Vips.Image
Description: Reference for Vips.Image

### Class

# VipsImage

#### Description [src]

    class Vips.Image : Vips.Object
    {
      /* No available fields */
    }

The `VipsImage` class and associated types and macros.

Images can be created from formatted files on disc, from C-style arrays on disc, from formatted areas of memory, or from C-style arrays in memory. See `vips_image_new_from_file()` and friends. Creating an image is fast. libvips reads just enough of the image to be able to get the various properties, such as width in pixels. It delays reading any pixels until they are really needed.

Once you have an image, you can get properties from it in the usual way. You can use projection functions, like `vips_image_get_width()` or `g_object_get()`, to get `GObject` properties.

`.v` images are three-dimensional arrays, the dimensions being width, height and bands. Each dimension can be up to 2 ** 31 pixels (or band elements). An image has a format, meaning the machine number type used to represent each value. libvips supports 10 formats, from 8-bit unsigned integer up to 128-bit double complex, see `vips_image_get_format()`.

In libvips, images are uninterpreted arrays, meaning that from the point of view of most operations, they are just large collections of numbers. There’s no difference between an RGBA (RGB with alpha) image and a CMYK image, for example, they are both just four-band images. It’s up to the user of the library to pass the right sort of image to each operation.

To take an example, libvips has `vips_Lab2XYZ()`, an operation to transform an image from CIE LAB colour space to CIE XYZ space. It assumes the first three bands represent pixels in LAB colour space and returns an image where the first three bands are transformed to XYZ and any remaining bands are just copied. Pass it an RGB image by mistake and you’ll just get nonsense.

libvips has a feature to help (a little) with this: it sets a `VipsInterpretation` hint for each image (see `vips_image_get_interpretation()`); a hint which says how pixels should be interpreted. For example, `vips_Lab2XYZ()` will set the interpretation of the output image to `VIPS_INTERPRETATION_XYZ`. A few utility operations will also use interpretation as a guide. For example, you can give `vips_colourspace()` an input image and a desired colourspace and it will use the input’s interpretation hint to apply the best sequence of colourspace transforms to get to the desired space.

Use things like `vips_invert()` to manipulate your images. When you are done, you can write images to disc files (with `vips_image_write_to_file()`), to formatted memory buffers (with `vips_image_write_to_buffer()`) and to C-style memory arrays (with `vips_image_write_to_memory()`).

You can also write images to other images. Create, for example, a temporary disc image with `vips_image_new_temp_file()`, then write your image to that with `vips_image_write()`. You can create several other types of image and write to them, see `vips_image_new_memory()`, for example.

See `VipsOperation` for an introduction to running operations on images, see Image headers for getting and setting image metadata. See `VipsObject` for a discussion of the lower levels.

#### Ancestors

- VipsObject
- GObject

#### Constructors

###### vips_image_memory

A renamed `vips_image_new_memory()` … Some gobject binding systems do not like more than one `_new()` method.

###### vips_image_new

`vips_image_new()` creates a new, empty `VipsImage`. If you write to one of these images, vips will just attach some callbacks, no pixels will be generated.

###### vips_image_new_from_buffer

Loads an image from the formatted area of memory `buf`, `len` using the loader recommended by `vips_foreign_find_load_buffer()`. To load an unformatted area of memory, use `vips_image_new_from_memory()`.

###### vips_image_new_from_file

`vips_image_new_from_file()` opens `name` for reading. It can load files in many image formats, including VIPS, TIFF, PNG, JPEG, FITS, Matlab, OpenEXR, CSV, WebP, Radiance, RAW, PPM and others.

###### vips_image_new_from_file_RW

Opens the named file for simultaneous reading and writing. This will only work for VIPS files in a format native to your machine. It is only for paintbox-type applications.

###### vips_image_new_from_file_raw

This function maps the named file and returns a `VipsImage` you can use to read it.

###### vips_image_new_from_image

Creates a new image with width, height, format, interpretation, resolution and offset taken from `image`, but with number of bands taken from `n` and the value of each band element set from `c`.

###### vips_image_new_from_image1

Creates a new image with width, height, format, interpretation, resolution and offset taken from `image`, but with one band and each pixel having the value `c`.

###### vips_image_new_from_memory

This function wraps a `VipsImage` around a memory area. The memory area must be a simple array, for example RGBRGBRGB, left-to-right, top-to-bottom. Use `vips_image_new_from_buffer()` to load an area of memory containing an image in a format.

###### vips_image_new_from_memory_copy

Like `vips_image_new_from_memory()`, but VIPS will make a copy of the memory area. This means more memory use and an extra copy operation, but is much simpler and safer.

###### vips_image_new_from_source

Loads an image from the formatted source `input`, loader recommended by `vips_foreign_find_load_source()`.

###### vips_image_new_matrix

This convenience function makes an image which is a matrix: a one-band `VIPS_FORMAT_DOUBLE` image held in memory.

###### vips_image_new_matrix_from_array

A binding-friendly version of `vips_image_new_matrixv()`.

###### vips_image_new_matrixv

As `vips_image_new_matrix()`, but initialise the matrix from the argument list. After `height` should be `width` * `height` double constants which are used to set the matrix elements.

###### vips_image_new_memory

`vips_image_new_memory()` creates a new `VipsImage` which, when written to, will create a memory image.

###### vips_image_new_temp_file

Make a `VipsImage` which, when written to, will create a temporary file on disc. The file will be automatically deleted when the image is destroyed. `format` is something like “%s.v” for a vips file.

###### vips_analyzeload

Load an Analyze 6.0 file. If `filename` is “fred.img”, this will look for an image header called “fred.hdr” and pixel data in “fred.img”. You can also load “fred” or “fred.hdr”.

###### vips_black

Make a black unsigned char image of a specified size.

###### vips_csvload

Load a CSV (comma-separated values) file.

###### vips_csvload_source

Exactly as `vips_csvload()`, but read from a source.

###### vips_eye

Create a test pattern with increasing spatial frequency in X and amplitude in Y.

###### vips_fitsload

Read a FITS image file into a VIPS image.

###### vips_fitsload_source

Exactly as `vips_fitsload()`, but read from a source.

###### vips_fractsurf

Generate an image of size `width` by `height` and fractal dimension `fractal_dimension`. The dimension should be between 2 and 3.

###### vips_gaussmat

Creates a circularly symmetric Gaussian image of radius `sigma`.

###### vips_gaussnoise

Make a one band float image of gaussian noise with the specified distribution.

###### vips_gifload

Read a GIF file into a libvips image.

###### vips_gifload_buffer

Exactly as `vips_gifload()`, but read from a memory buffer.

###### vips_gifload_source

Exactly as `vips_gifload()`, but read from a source.

###### vips_grey

Create a one-band float image with the left-most column zero and the right-most 1.

###### vips_heifload

Read a HEIF image file into a VIPS image.

###### vips_heifload_buffer

Read a HEIF image file into a VIPS image. Exactly as `vips_heifload()`, but read from a memory buffer.

###### vips_heifload_source

Exactly as `vips_heifload()`, but read from a source.

###### vips_identity

Creates an identity lookup table, ie. one which will leave an image unchanged when applied with `vips_maplut()`. Each entry in the table has a value equal to its position.

###### vips_jp2kload

Read a JPEG2000 image.

###### vips_jp2kload_buffer

Exactly as `vips_jp2kload()`, but read from a buffer.

###### vips_jp2kload_source

Exactly as `vips_jp2kload()`, but read from a source.

###### vips_jpegload

Read a JPEG file into a VIPS image. It can read most 8-bit JPEG images, including CMYK and YCbCr.

###### vips_jpegload_buffer

Read a JPEG-formatted memory block into a VIPS image. Exactly as `vips_jpegload()`, but read from a memory buffer.

###### vips_jpegload_source

Read a JPEG-formatted memory block into a VIPS image. Exactly as `vips_jpegload()`, but read from a source.

###### vips_jxlload

Read a JPEG-XL image.

###### vips_jxlload_buffer

Exactly as `vips_jxlload()`, but read from a buffer.

###### vips_jxlload_source

Exactly as `vips_jxlload()`, but read from a source.

###### vips_logmat

Create a circularly symmetric Laplacian of Gaussian mask of radius `sigma`.

###### vips_magickload

Read in an image using libMagick, the ImageMagick library.

###### vips_magickload_buffer

Read an image memory block using libMagick into a VIPS image. Exactly as `vips_magickload()`, but read from a memory source.

###### vips_mask_butterworth

Make an butterworth high- or low-pass filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff`, where `frequency_cutoff` is in range 0 - 1.

###### vips_mask_butterworth_band

Make an butterworth band-pass or band-reject filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff_x`, `frequency_cutoff_y`, of radius `radius`.

###### vips_mask_butterworth_ring

Make a butterworth ring-pass or ring-reject filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff` of width `width`, where `frequency_cutoff` is in the range 0 - 1.

###### vips_mask_fractal

This operation should be used to create fractal images by filtering the power spectrum of Gaussian white noise.

###### vips_mask_gaussian

Make a gaussian high- or low-pass filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff`.

###### vips_mask_gaussian_band

Make a gaussian band-pass or band-reject filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff_x`, `frequency_cutoff_y`, of radius `radius`.

###### vips_mask_gaussian_ring

Make a gaussian ring-pass or ring-reject filter, that is, one with a variable, smooth transition positioned at `frequency_cutoff` of width `ringwidth`.

###### vips_mask_ideal

Make an ideal high- or low-pass filter, that is, one with a sharp cutoff positioned at `frequency_cutoff`, where `frequency_cutoff` is in the range 0 - 1.

###### vips_mask_ideal_band

Make an ideal band-pass or band-reject filter, that is, one with a sharp cutoff around the point `frequency_cutoff_x`, `frequency_cutoff_y`, of size `radius`.

###### vips_mask_ideal_ring

Make an ideal ring-pass or ring-reject filter, that is, one with a sharp ring positioned at `frequency_cutoff` of width `width`, where `frequency_cutoff` and `width` are expressed as the range 0 - 1.

###### vips_matload

Read a Matlab save file into a VIPS image.

###### vips_matrixload

Reads a matrix from a file.

###### vips_matrixload_source

Exactly as `vips_matrixload()`, but read from a source.

###### vips_niftiload

Read a NIFTI image file into a VIPS image.

###### vips_niftiload_source

Exactly as `vips_niftiload()`, but read from a source.

###### vips_openexrload

Read a OpenEXR file into a VIPS image.

###### vips_openslideload

Read a virtual slide supported by the OpenSlide library into a VIPS image. OpenSlide supports images in Aperio, Hamamatsu, MIRAX, Sakura, Trestle, and Ventana formats.

###### vips_openslideload_source

Exactly as `vips_openslideload()`, but read from a source.

###### vips_pdfload

Render a PDF file into a VIPS image.

###### vips_pdfload_buffer

Read a PDF-formatted memory buffer into a VIPS image. Exactly as `vips_pdfload()`, but read from memory.

###### vips_pdfload_source

Exactly as `vips_pdfload()`, but read from a source.

###### vips_perlin

Create a one-band float image of Perlin noise.

###### vips_pngload

Read a PNG file into a VIPS image. It can read all png images, including 8- and 16-bit images, 1 and 3 channel, with and without an alpha channel.

###### vips_pngload_buffer

Exactly as `vips_pngload()`, but read from a PNG-formatted memory block.

###### vips_pngload_source

Exactly as `vips_pngload()`, but read from a source.

###### vips_ppmload

Read a PPM/PBM/PGM/PFM file into a VIPS image.

###### vips_ppmload_buffer

Exactly as `vips_ppmload()`, but read from a memory source.

###### vips_ppmload_source

Exactly as `vips_ppmload()`, but read from a source.

###### vips_radload

Read a Radiance (HDR) file into a VIPS image.

###### vips_radload_buffer

Exactly as `vips_radload()`, but read from a HDR-formatted memory block.

###### vips_radload_source

Exactly as `vips_radload()`, but read from a source.

###### vips_rawload

This operation mmaps the file, setting up `out` so that access to that image will read from the file.

###### vips_sdf

Create a signed distance field (SDF) image of the given `shape`.

###### vips_sines

Creates a float one band image of the a sine waveform in two dimensions.

###### vips_svgload

Render a SVG file into a VIPS image.

###### vips_svgload_buffer

Read a SVG-formatted memory block into a VIPS image. Exactly as `vips_svgload()`, but read from a memory buffer.

###### vips_svgload_source

Exactly as `vips_svgload()`, but read from a source.

###### vips_svgload_string

Exactly as `vips_svgload()`, but read from a string. This function takes a copy of the string.

###### vips_system

`vips_system()` runs a command, optionally passing a set of images in and optionally getting an image back. The command’s stdout is returned in `log`.

###### vips_text

Draw the string `text` to an image.

###### vips_thumbnail

Make a thumbnail from a file.

###### vips_thumbnail_buffer

Exactly as `vips_thumbnail()`, but read from a memory buffer.

###### vips_thumbnail_source

Exactly as `vips_thumbnail()`, but read from a source.

###### vips_tiffload

Read a TIFF file into a VIPS image.

###### vips_tiffload_buffer

Read a TIFF-formatted memory block into a VIPS image. Exactly as `vips_tiffload()`, but read from a memory source.

###### vips_tiffload_source

Exactly as `vips_tiffload()`, but read from a source.

###### vips_tonelut

`vips_tonelut()` generates a tone curve for the adjustment of image levels.

###### vips_vipsload

Read in a vips image.

###### vips_vipsload_source

Exactly as `vips_vipsload()`, but read from a source.

###### vips_webpload

Read a WebP file into a VIPS image.

###### vips_webpload_buffer

Read a WebP-formatted memory block into a VIPS image. Exactly as `vips_webpload()`, but read from a memory buffer.

###### vips_webpload_source

Exactly as `vips_webpload()`, but read from a source.

###### vips_worley

Create a one-band float image of Worley noise.

###### vips_xyz

Create a two-band uint32 image where the elements in the first band have the value of their x coordinate and elements in the second band have their y coordinate.

###### vips_zone

Create a one-band image of a zone plate.

#### Functions

###### vips_image_get_format_max

No description available.

###### vips_image_matrix_from_array

A renamed `vips_image_new_matrix_from_array()`. Some gobject bindings do not like more than one _new method.

###### vips_image_pipeline_array

Add an image to a pipeline. `image` depends on all of the images in `in`, `image` prefers to supply pixels according to `hint`.

###### vips_arrayjoin

Lay out the images in `in` in a grid. The grid is `across` images across and however high is necessary to use up all of `in`. Images are set down left-to-right and top-to-bottom. `across` defaults to `n`.

###### vips_bandjoin

Join a set of images together, bandwise.

###### vips_bandrank

Sorts the images `in` band-element-wise, then outputs an image in which each band element is selected from the sorted list by the `index` parameter. For example, if `index` is zero, then each output band element will be the minimum of all the corresponding input band elements.

###### vips_composite

Composite an array of images together.

###### vips_sum

This operation sums all images in `in` and writes the result to `out`.

###### vips_switch

The `tests` images are evaluated and at each point the index of the first non-zero value is written to `out`. If all `tests` are false, the value (`n` + 1) is written.

#### Instance methods

###### vips_CMC2LCh

Turn LCh to CMC.

###### vips_CMYK2XYZ

Turn CMYK to XYZ. If the image has an embedded ICC profile this will be used for the conversion. If there is no embedded profile, a generic fallback profile will be used.

###### vips_HSV2sRGB

Convert HSV to sRGB.

###### vips_LCh2CMC

Turn LCh to CMC.

###### vips_LCh2Lab

Turn LCh to Lab.

###### vips_Lab2LCh

Turn Lab to LCh.

###### vips_Lab2LabQ

Convert a Lab three-band float image to LabQ (`VIPS_CODING_LABQ`).

###### vips_Lab2LabS

Turn Lab to LabS, signed 16-bit int fixed point.

###### vips_Lab2XYZ

Turn Lab to XYZ. The colour temperature defaults to D65, but can be specified with `temp`.

###### vips_LabQ2Lab

Unpack a LabQ (`VIPS_CODING_LABQ`) image to a three-band float image.

###### vips_LabQ2LabS

Unpack a LabQ (`VIPS_CODING_LABQ`) image to a three-band short image.

###### vips_LabQ2sRGB

Unpack a LabQ (`VIPS_CODING_LABQ`) image to a three-band short image.

###### vips_LabS2Lab

Convert a LabS three-band signed short image to a three-band float image.

###### vips_LabS2LabQ

Convert a LabS three-band signed short image to LabQ.

###### vips_XYZ2CMYK

Turn XYZ to CMYK.

###### vips_XYZ2Lab

Turn XYZ to Lab, optionally specifying the colour temperature. `temp` defaults to D65.

###### vips_XYZ2Yxy

Turn XYZ to Yxy.

###### vips_XYZ2scRGB

Turn XYZ to scRGB.

###### vips_Yxy2XYZ

Turn XYZ to Yxy.

###### vips_abs

This operation finds the absolute value of an image. It does a copy for unsigned integer types, negate for negative values in signed integer types, `fabs()` for float types, and calculates modulus for complex types.

###### vips_acos

Perform `VIPS_OPERATION_MATH_ACOS` on an image. See `vips_math()`.

###### vips_acosh

Perform `VIPS_OPERATION_MATH_ACOSH` on an image. See `vips_math()`.

###### vips_add

This operation calculates `in1` + `in2` and writes the result to `out`.

###### vips_addalpha

Append an alpha channel.

###### vips_affine

This operator performs an affine transform on an image using `interpolate`.

###### vips_andimage

Perform `VIPS_OPERATION_BOOLEAN_AND` on a pair of images. See `vips_boolean()`.

###### vips_andimage_const

Perform `VIPS_OPERATION_BOOLEAN_AND` on an image and an array of constants. See `vips_boolean_const()`.

###### vips_andimage_const1

Perform `VIPS_OPERATION_BOOLEAN_AND` on an image and a constant. See `vips_boolean_const1()`.

###### vips_asin

Perform `VIPS_OPERATION_MATH_ASIN` on an image. See `vips_math()`.

###### vips_asinh

Perform `VIPS_OPERATION_MATH_ASINH` on an image. See `vips_math()`.

###### vips_atan

Perform `VIPS_OPERATION_MATH_ATAN` on an image. See `vips_math()`.

###### vips_atan2

Perform `VIPS_OPERATION_MATH2_ATAN2` on a pair of images. See `vips_math2()`.

###### vips_atan2_const

Perform `VIPS_OPERATION_MATH2_ATAN2` on an image and a constant. See `vips_math2_const()`.

###### vips_atan2_const1

Perform `VIPS_OPERATION_MATH2_ATAN2` on an image and a constant. See `vips_math2_const()`.

###### vips_atanh

Perform `VIPS_OPERATION_MATH_ATANH` on an image. See `vips_math()`.

###### vips_autorot

Look at the image metadata and rotate and flip the image to make it upright. The `VIPS_META_ORIENTATION` tag is removed from `out` to prevent accidental double rotation.

###### vips_autorot_remove_angle

Remove the orientation tag on `image`. Also remove any exif orientation tags. You must `vips_copy()` the image before calling this function since it modifies metadata.

###### vips_avg

This operation finds the average value in an image. It operates on all bands of the input image: use `vips_stats()` if you need to calculate an average for each band. For complex images, return the average modulus.

###### vips_bandand

Perform `VIPS_OPERATION_BOOLEAN_AND` on an image. See `vips_bandbool()`.

###### vips_bandbool

Perform various boolean operations across the bands of an image. For example, a three-band uchar image operated on with `VIPS_OPERATION_BOOLEAN_AND` will produce a one-band uchar image where each pixel is the bitwise and of the band elements of the corresponding pixel in the input image.

###### vips_bandeor

Perform `VIPS_OPERATION_BOOLEAN_EOR` on an image. See `vips_bandbool()`.

###### vips_bandfold

Fold up an image horizontally: width is collapsed into bands. Use `factor` to set how much to fold by: `factor` 3, for example, will make the output image three times narrower than the input, and with three times as many bands. By default the whole of the input width is folded up.

###### vips_bandjoin2

Join a pair of images together, bandwise. See `vips_bandjoin()`.

###### vips_bandjoin_const

Append a set of constant bands to an image.

###### vips_bandjoin_const1

Append a single constant band to an image.

###### vips_bandmean

This operation writes a one-band image where each pixel is the average of the bands for that pixel in the input image. The output band format is the same as the input band format. Integer types use round-to-nearest averaging.

###### vips_bandor

Perform `VIPS_OPERATION_BOOLEAN_OR` on an image. See `vips_bandbool()`.

###### vips_bandunfold

Unfold image bands into x axis. Use `factor` to set how much to unfold by: `factor` 3, for example, will make the output image three times wider than the input, and with one third as many bands. By default, all bands are unfolded.

###### vips_boolean

Perform various boolean operations on pairs of images.

###### vips_boolean_const

Perform various boolean operations on an image against an array of constants.

###### vips_boolean_const1

Perform various boolean operations on an image with a single constant. See `vips_boolean_const()`.

###### vips_buildlut

This operation builds a lookup table from a set of points. Intermediate values are generated by piecewise linear interpolation. The lookup table is always of type `VIPS_FORMAT_DOUBLE`, use `vips_cast()` to change it to the type you need.

###### vips_byteswap

Swap the byte order in an image.

###### vips_canny

Find edges by Canny’s method: The maximum of the derivative of the gradient in the direction of the gradient. Output is float, except for uchar input, where output is uchar, and double input, where output is double. Non-complex images only.

###### vips_case

Use values in `index` to select pixels from `cases`.

###### vips_cast

Convert `in` to `format`. You can convert between any pair of formats. Floats are truncated (not rounded). Out of range values are clipped.

###### vips_cast_char

Convert `in` to `VIPS_FORMAT_CHAR`. See `vips_cast()`.

###### vips_cast_complex

Convert `in` to `VIPS_FORMAT_COMPLEX`. See `vips_cast()`.

###### vips_cast_double

Convert `in` to `VIPS_FORMAT_DOUBLE`. See `vips_cast()`.

###### vips_cast_dpcomplex

Convert `in` to `VIPS_FORMAT_DPCOMPLEX`. See `vips_cast()`.

###### vips_cast_float

Convert `in` to `VIPS_FORMAT_FLOAT`. See `vips_cast()`.

###### vips_cast_int

Convert `in` to `VIPS_FORMAT_INT`. See `vips_cast()`.

###### vips_cast_short

Convert `in` to `VIPS_FORMAT_SHORT`. See `vips_cast()`.

###### vips_cast_uchar

Convert `in` to `VIPS_FORMAT_UCHAR`. See `vips_cast()`.

###### vips_cast_uint

Convert `in` to `VIPS_FORMAT_UINT`. See `vips_cast()`.

###### vips_cast_ushort

Convert `in` to `VIPS_FORMAT_USHORT`. See `vips_cast()`.

###### vips_ceil

Round to an integral value with `VIPS_OPERATION_ROUND_CEIL`. See `vips_round()`.

###### vips_clamp

This operation clamps pixel values to a range, by default 0 - 1.

###### vips_colourspace

This operation looks at the interpretation field of `in` (or uses `source_space`, if set) and runs a set of colourspace conversion functions to move it to `space`.

###### vips_colourspace_issupported

Test if `image` is in a colourspace that `vips_colourspace()` can process.

###### vips_compass

This convolves `in` with `mask` `times` times, rotating `mask` by `angle` each time. By default, it comvolves twice, rotating by 90 degrees, taking the maximum result.

###### vips_complex

Perform various operations on complex images.

###### vips_complex2

Perform various binary operations on complex images.

###### vips_complexform

Compose two real images to make a complex image. If either `left` or `right` are `VIPS_FORMAT_DOUBLE`, `out` is `VIPS_FORMAT_DPCOMPLEX`. Otherwise `out` is `VIPS_FORMAT_COMPLEX`. `left` becomes the real component of `out` and `right` the imaginary.

###### vips_complexget

Get components of complex images.

###### vips_composite2

Composite `overlay` on top of `base` with `mode`. See `vips_composite()`.

###### vips_conj

Perform `VIPS_OPERATION_COMPLEX_CONJ` on an image. See `vips_complex()`.

###### vips_conv

Perform a convolution of `in` with `mask`.

###### vips_conva

Perform an approximate integer convolution of `in` with `mask`. This is a low-level operation, see `vips_conv()` for something more convenient.

###### vips_convasep

Approximate separable integer convolution. This is a low-level operation, see `vips_convsep()` for something more convenient.

###### vips_convf

Convolution. This is a low-level operation, see `vips_conv()` for something more convenient.

###### vips_convi

Integer convolution. This is a low-level operation, see `vips_conv()` for something more convenient.

###### vips_convsep

Perform a separable convolution of `in` with `mask`. See `vips_conv()` for a detailed description.

###### vips_copy

Copy an image, optionally modifying the header. VIPS copies images by copying pointers, so this operation is instant, even for very large images.

###### vips_copy_file

A simple convenience function to copy an image to a file, then copy again to output. If the image is already a file, just copy straight through.

###### vips_image_copy_memory

This function allocates memory, renders `image` into it, builds a new image around the memory area, and returns that.

###### vips_cos

Perform `VIPS_OPERATION_MATH_COS` on an image. See `vips_math()`.

###### vips_cosh

Perform `VIPS_OPERATION_MATH_COSH` on an image. See `vips_math()`.

###### vips_countlines

Function which calculates the number of transitions between black and white for the horizontal or the vertical direction of an image. black<128 , white>=128 The function calculates the number of transitions for all Xsize or Ysize and returns the mean of the result Input should be one band, 8-bit.

###### vips_crop

A synonym for `vips_extract_area()`.

###### vips_cross_phase

Perform `VIPS_OPERATION_COMPLEX2_CROSS_PHASE` on an image. See `vips_complex2()`.

###### vips_csvsave

Writes the pixels in `in` to the `filename` as CSV (comma-separated values).

###### vips_csvsave_target

As `vips_csvsave()`, but save to a target.

###### vips_dE00

Calculate dE 00.

###### vips_dE76

Calculate dE 76.

###### vips_dECMC

Calculate dE CMC. The input images are transformed to CMC colour space and the euclidean distance between corresponding pixels calculated.

###### vips_image_decode

A convenience function to unpack to a format that we can compute with. `out`.coding is always `VIPS_CODING_NONE`.

###### vips_image_decode_predict

We often need to know what an image will decode to without actually decoding it, for example, in arg checking.

###### vips_deviate

This operation finds the standard deviation of all pixels in `in`. It operates on all bands of the input image: use `vips_stats()` if you need to calculate an average for each band.

###### vips_divide

This operation calculates `in1` / `in2` and writes the result to `out`. If any pixels in `in2` are zero, the corresponding pixel in `out` is also zero.

###### vips_draw_circle

Draws a circle on `image`.

###### vips_draw_circle1

As `vips_draw_circle()`, but just takes a single double for `ink`.

###### vips_draw_flood

Flood-fill `image` with `ink`, starting at position `x`, `y`.

###### vips_draw_flood1

As `vips_draw_flood()`, but just takes a single double for `ink`.

###### vips_draw_image

Draw `sub` on top of `image` at position `x`, `y`.

###### vips_draw_line

Draws a 1-pixel-wide line on an image.

###### vips_draw_line1

As `vips_draw_line()`, but just take a single double for `ink`.

###### vips_draw_mask

Draw `mask` on the image. `mask` is a monochrome 8-bit image with 0/255 for transparent or `ink` coloured points. Intermediate values blend the ink with the pixel. Use with `vips_text()` to draw text on an image. Use in a `vips_draw_line()` subclass to draw an object along a line.

###### vips_draw_mask1

As `vips_draw_mask()`, but just takes a single double for `ink`.

###### vips_draw_point

As `vips_draw_rect()`, but draw a single pixel at `x`, `y`.

###### vips_draw_point1

As `vips_draw_point()`, but just take a single double for `ink`.

###### vips_draw_rect

Paint pixels within `left`, `top`, `width`, `height` in `image` with `ink`.

###### vips_draw_rect1

As `vips_draw_rect()`, but just take a single double for `ink`.

###### vips_draw_smudge

Smudge a section of `image`. Each pixel in the area `left`, `top`, `width`, `height` is replaced by the average of the surrounding 3x3 pixels.

###### vips_dzsave

Save an image as a set of tiles at various resolutions. By default dzsave uses DeepZoom layout — use `layout` to pick other conventions.

###### vips_dzsave_buffer

As `vips_dzsave()`, but save to a memory buffer.

###### vips_dzsave_target

As `vips_dzsave()`, but save to a target.

###### vips_embed

The opposite of `vips_extract_area()`: embed `in` within an image of size `width` by `height` at position `x`, `y`.

###### vips_image_encode

A convenience function to pack to a coding. The inverse of `vips_image_decode()`.

###### vips_eorimage

Perform `VIPS_OPERATION_BOOLEAN_EOR` on a pair of images. See `vips_boolean()`.

###### vips_eorimage_const

Perform `VIPS_OPERATION_BOOLEAN_EOR` on an image and an array of constants. See `vips_boolean_const()`.

###### vips_eorimage_const1

Perform `VIPS_OPERATION_BOOLEAN_EOR` on an image and a constant. See `vips_boolean_const1()`.

###### vips_equal

Perform `VIPS_OPERATION_RELATIONAL_EQUAL` on a pair of images. See `vips_relational()`.

###### vips_equal_const

Perform `VIPS_OPERATION_RELATIONAL_EQUAL` on an image and a constant. See `vips_relational_const()`.

###### vips_equal_const1

Perform `VIPS_OPERATION_RELATIONAL_EQUAL` on an image and a constant. See `vips_relational_const()`.

###### vips_image_eval

No description available.

###### vips_exp

Perform `VIPS_OPERATION_MATH_EXP` on an image. See `vips_math()`.

###### vips_exp10

Perform `VIPS_OPERATION_MATH_EXP10` on an image. See `vips_math()`.

###### vips_extract_area

Extract an area from an image. The area must fit within `in`.

###### vips_extract_band

Extract a band or bands from an image. Extracting out of range is an error.

###### vips_falsecolour

Force `in` to 1 band, 8-bit, then transform to a 3-band 8-bit image with a false colour map. The map is supposed to make small differences in brightness more obvious.

###### vips_fastcor

Calculate a fast correlation surface.

###### vips_fill_nearest

Fill outwards from every non-zero pixel in `in`, setting pixels in `distance` and `value`.

###### vips_find_trim

Search `in` for the bounding box of the non-background area.

###### vips_fitssave

Write a VIPS image to a file in FITS format.

###### vips_flatten

Take the last band of `in` as an alpha and use it to blend the remaining channels with `background`.

###### vips_flip

Flips an image left-right or up-down.

###### vips_float2rad

Convert a three-band float image to Radiance 32-bit packed format.

###### vips_floor

Round to an integral value with `VIPS_OPERATION_ROUND_FLOOR`. See `vips_round()`.

###### vips_foreign_load_invalidate

Loaders can call this on the image they are making if they see a read error from the load library. It signals “invalidate” on the load operation and will cause it to be dropped from cache.

###### vips_image_free_buffer

Free the externally allocated buffer found in the input image. This function is intended to be used with g_signal_connect.

###### vips_freqmult

Multiply `in` by `mask` in Fourier space.

###### vips_fwfft

Transform an image to Fourier space.

###### vips_gamma

Calculate `in` ** (1 / `exponent`), normalising to the maximum range of the input type. For float types use 1.0 as the maximum.

###### vips_gaussblur

This operator runs `vips_gaussmat()` and `vips_convsep()` for you on an image.

###### vips_image_generate

Generates an image. The action depends on the image type.

###### vips_image_get

Fill `value_copy` with a copy of the header field. `value_copy` must be zeroed but uninitialised.

###### vips_image_get_area

Gets `data` from `image` under the name `name`. A convenience function over `vips_image_get()`. Use `vips_image_get_typeof()` to test for the existence of a piece of metadata.

###### vips_image_get_array_double

Gets `out` from `im` under the name `name`. The field must be of type `VIPS_TYPE_ARRAY_INT`.

###### vips_image_get_array_int

Gets `out` from `im` under the name `name`. The field must be of type `VIPS_TYPE_ARRAY_INT`.

###### vips_image_get_as_string

Returns `name` from `image` in `out`. This function will read any field, returning it as a printable string. You need to free the string with `g_free()` when you are done with it.

###### vips_image_get_bands

No description available.

###### vips_image_get_blob

Gets `data` from `image` under the name `name`, optionally returns its length in `length`. Use `vips_image_get_typeof()` to test for the existence of a piece of metadata.

###### vips_image_get_coding

No description available.

###### vips_image_get_concurrency

Fetch and sanity-check `VIPS_META_CONCURRENCY`. Default to 1 if not present or crazy.

###### vips_image_get_data

Return a pointer to the image’s pixel data, if possible. This can involve allocating large amounts of memory and performing a long computation. Image pixels are laid out in band-packed rows.

###### vips_image_get_double

Gets `out` from `im` under the name `name`. The value will be transformed into a double, if possible.

###### vips_image_get_fields

Get a `NULL`-terminated array listing all the metadata field names on `image`. Free the return result with `g_strfreev()`.

###### vips_image_get_filename

No description available.

###### vips_image_get_format

No description available.

###### vips_image_get_height

No description available.

###### vips_image_get_history

This function reads the image history as a C string. The string is owned by VIPS and must not be freed.

###### vips_image_get_image

Gets `out` from `im` under the name `name`. The field must be of type `VIPS_TYPE_IMAGE`. You must unref `out` with `g_object_unref()`.

###### vips_image_get_int

Gets `out` from `im` under the name `name`. The value will be transformed into an int, if possible.

###### vips_image_get_interpretation

Return the `VipsInterpretation` set in the image header. Use `vips_image_guess_format()` if you want a sanity-checked value.

###### vips_image_get_mode

Image modes are things like `"t"`, meaning a memory buffer, and `"p"` meaning a delayed computation.

###### vips_image_get_n_pages

Fetch and sanity-check `VIPS_META_N_PAGES`. Default to 1 if not present or crazy.

###### vips_image_get_n_subifds

Fetch and sanity-check `VIPS_META_N_SUBIFDS`. Default to 0 if not present or crazy.

###### vips_image_get_offset

Matrix images can have an optional `offset` field for use by integer convolution.

###### vips_image_get_orientation

Fetch and sanity-check `VIPS_META_ORIENTATION`. Default to 1 (no rotate, no flip) if not present or crazy.

###### vips_image_get_orientation_swap

Return `TRUE` if applying the orientation would swap width and height.

###### vips_image_get_page_height

Multi-page images can have a page height. Fetch it, and sanity check it. If page-height is not set, it defaults to the image height.

###### vips_image_get_scale

Matrix images can have an optional `scale` field for use by integer convolution.

###### vips_image_get_string

Gets `out` from `im` under the name `name`. The field must be of type `G_TYPE_STRING` or `VIPS_TYPE_REF_STRING`.

###### vips_get_tile_size

Pick a tile size and a buffer height for this image and the current value of `vips_concurrency_get()`. The buffer height will always be a multiple of tile_height.

###### vips_image_get_typeof

Read the `GType` for a header field. Returns zero if there is no field of that name.

###### vips_image_get_width

No description available.

###### vips_image_get_xoffset

No description available.

###### vips_image_get_xres

No description available.

###### vips_image_get_yoffset

No description available.

###### vips_image_get_yres

No description available.

###### vips_getpoint

Reads a single pixel on an image.

###### vips_gifsave

Write to a file in GIF format.

###### vips_gifsave_buffer

As `vips_gifsave()`, but save to a memory buffer.

###### vips_gifsave_target

As `vips_gifsave()`, but save to a target.

###### vips_globalbalance

`vips_globalbalance()` can be used to remove contrast differences in an assembled mosaic.

###### vips_gravity

The opposite of `vips_extract_area()`: place `in` within an image of size `width` by `height` at a certain gravity.

###### vips_grid

Chop a tall thin image up into a set of tiles, lay the tiles out in a grid.

###### vips_image_guess_format

Return the `VipsBandFormat` for an image, guessing a sane value if the set value looks crazy.

###### vips_image_guess_interpretation

Return the `VipsInterpretation` for an image, guessing a sane value if the set value looks crazy.

###### vips_image_hasalpha

Look at an image’s interpretation and see if it has extra alpha bands. For example, a 4-band `VIPS_INTERPRETATION_sRGB` would, but a six-band `VIPS_INTERPRETATION_MULTIBAND` would not.

###### vips_heifsave

Write a VIPS image to a file in HEIF format.

###### vips_heifsave_buffer

As `vips_heifsave()`, but save to a memory buffer.

###### vips_heifsave_target

As `vips_heifsave()`, but save to a target.

###### vips_hist_cum

Form cumulative histogram.

###### vips_hist_entropy

Estimate image entropy from a histogram. Entropy is calculated as:.

###### vips_hist_equal

Histogram-equalise `in`.

###### vips_hist_find

Find the histogram of `in`. Find the histogram for band `band` (producing a one-band histogram), or for all bands (producing an n-band histogram) if `band` is -1.

###### vips_hist_find_indexed

Make a histogram of `in`, but use image `index` to pick the bins. In other words, element zero in `out` contains the combination of all the pixels in `in` whose corresponding pixel in `index` is zero.

###### vips_hist_find_ndim

Make a one, two or three dimensional histogram of a 1, 2 or 3 band image. Divide each axis into `bins` bins .. ie. output is 1 x bins, bins x bins, or bins x bins x bins bands. `bins` defaults to 10.

###### vips_hist_ismonotonic

Test `in` for monotonicity. `out` is set non-zero if `in` is monotonic.

###### vips_hist_local

Performs local histogram equalisation on `in` using a window of size `width` by `height` centered on the input pixel.

###### vips_hist_match

Adjust `in` to match `ref`. If `in` and `ref` are normalised cumulative histograms, `out` will be a LUT that adjusts the PDF of the image from which `in` was made to match the PDF of `ref`‘s image.

###### vips_hist_norm

Normalise histogram. The maximum of each band becomes equal to the maximum index, so for example the max for a uchar image becomes 255. Normalise each band separately.

###### vips_hist_plot

Plot a 1 by any or any by 1 image file as a max by any or any by max image using these rules:.

###### vips_image_history_args

Formats the name/argv as a single string and calls `vips_image_history_printf()`. A convenience function for command-line programs.

###### vips_image_history_printf

Add a line to the image history. The `format` and arguments are expanded, the date and time is appended prefixed with a hash character, and the whole string is appended to the image history and terminated with a newline.

###### vips_hough_circle

Find the circular Hough transform of an image. `in` must be one band, with non-zero pixels for image edges. `out` is three-band, with the third channel representing the detected circle radius. The operation scales the number of votes by circle circumference so circles of differing size are given equal weight.

###### vips_hough_line

Find the line Hough transform for `in`. `in` must have one band. `out` has one band, with pixels being the number of votes for that line. The X dimension of `out` is the line angle in 0 - 180 degrees, the Y dimension is the distance of the closest part of that line to the origin in the top-left.

###### vips_icc_ac2rc

Transform an image from absolute to relative colorimetry using the MediaWhitePoint stored in the ICC profile.

###### vips_icc_export

Export an image from D65 LAB to device space with an ICC profile.

###### vips_icc_import

Import an image from device space to D65 LAB with an ICC profile.

###### vips_icc_transform

Transform an image with a pair of ICC profiles.

###### vips_ifthenelse

This operation scans the condition image `cond` and uses it to select pixels from either the then image `in1` or the else image `in2`. Non-zero means `in1`, 0 means `in2`.

###### vips_imag

Perform `VIPS_OPERATION_COMPLEXGET_IMAG` on an image. See `vips_complexget()`.

###### vips_image_init_fields

A convenience function to set the header fields after creating an image. Normally you copy the fields from your input images with [method.Image.pipelinev] and then make any adjustments you need, but if you are creating an image from scratch, for example `vips_black()` or `vips_jpegload()`, you do need to set all the fields yourself.

###### vips_image_inplace

Gets `image` ready for an in-place operation, such as `vips_draw_circle()`. After calling this function you can both read and write the image with `VIPS_IMAGE_ADDR()`.

###### vips_insert

Insert `sub` into `main` at position `x`, `y`.

###### vips_image_invalidate_all

Invalidate all pixel caches on `image` and any downstream images, that is, images which depend on this image. Additionally, all operations which depend upon this image are dropped from the VIPS operation cache.

###### vips_invert

For unsigned formats, this operation calculates (max - `in`), eg. (255 - `in`) for uchar. For signed and float formats, this operation calculates (-1 `in`).

###### vips_invertlut

Given a mask of target values and real values, generate a LUT which will map reals to targets.

###### vips_invfft

Transform an image from Fourier space to real space.

###### vips_image_isMSBfirst

Return `TRUE` if `image` is in most-significant- byte first form. This is the byte order used on the SPARC architecture and others.

###### vips_image_is_sequential

`TRUE` if any of the images upstream from `image` were opened in sequential mode. Some operations change behaviour slightly in sequential mode to optimize memory behaviour.

###### vips_image_isfile

Return `TRUE` if `image` represents a file on disc in some way.

###### vips_image_iskilled

If `image` has been killed (see `vips_image_set_kill()`), set an error message, clear the `VipsImage`.kill flag and return `TRUE`. Otherwise return `FALSE`.

###### vips_image_ispartial

Return `TRUE` if `im` represents a partial image (a delayed calculation).

###### vips_join

Join `in1` and `in2` together, left-right or up-down depending on the value of `direction`.

###### vips_jp2ksave

Write a VIPS image to a file in JPEG2000 format.

###### vips_jp2ksave_buffer

As `vips_jp2ksave()`, but save to a target.

###### vips_jp2ksave_target

As `vips_jp2ksave()`, but save to a target.

###### vips_jpegsave

Write a VIPS image to a file as JPEG.

###### vips_jpegsave_buffer

As `vips_jpegsave()`, but save to a memory buffer.

###### vips_jpegsave_mime

As `vips_jpegsave()`, but save as a mime jpeg on stdout.

###### vips_jpegsave_target

As `vips_jpegsave()`, but save to a target.

###### vips_jxlsave

Write a VIPS image to a file in JPEG-XL format.

###### vips_jxlsave_buffer

As `vips_jxlsave()`, but save to a memory buffer.

###### vips_jxlsave_target

As `vips_jxlsave()`, but save to a target.

###### vips_labelregions

Label regions of equal pixels in an image.

###### vips_less

Perform `VIPS_OPERATION_RELATIONAL_LESS` on a pair of images. See `vips_relational()`.

###### vips_less_const

Perform `VIPS_OPERATION_RELATIONAL_LESS` on an image and a constant. See `vips_relational_const()`.

###### vips_less_const1

Perform `VIPS_OPERATION_RELATIONAL_LESS` on an image and a constant. See `vips_relational_const()`.

###### vips_lesseq

Perform `VIPS_OPERATION_RELATIONAL_LESSEQ` on a pair of images. See `vips_relational()`.

###### vips_lesseq_const

Perform `VIPS_OPERATION_RELATIONAL_LESSEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_lesseq_const1

Perform `VIPS_OPERATION_RELATIONAL_LESSEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_linear

Pass an image through a linear transform, ie. (`out` = `in` * `a` + `b`). Output is float for integer input, double for double input, complex for complex input and double complex for double complex input. Set `uchar` to output uchar pixels.

###### vips_linear1

Run `vips_linear()` with a single constant.

###### vips_linecache

This operation behaves rather like `vips_copy()` between images `in` and `out`, except that it keeps a cache of computed scanlines.

###### vips_log

Perform `VIPS_OPERATION_MATH_LOG` on an image. See `vips_math()`.

###### vips_log10

Perform `VIPS_OPERATION_MATH_LOG10` on an image. See `vips_math()`.

###### vips_lshift

Perform `VIPS_OPERATION_BOOLEAN_LSHIFT` on a pair of images. See `vips_boolean()`.

###### vips_lshift_const

Perform `VIPS_OPERATION_BOOLEAN_LSHIFT` on an image and an array of constants. See `vips_boolean_const()`.

###### vips_lshift_const1

Perform `VIPS_OPERATION_BOOLEAN_LSHIFT` on an image and a constant. See `vips_boolean_const1()`.

###### vips_magicksave

Write an image using libMagick.

###### vips_magicksave_buffer

As `vips_magicksave()`, but save to a memory buffer.

###### vips_image_map

This function calls `fn` for every header field, including every item of metadata.

###### vips_mapim

This operator resamples `in` using `index` to look up pixels.

###### vips_maplut

Map an image through another image acting as a LUT (Look Up Table). The lut may have any type and the output image will be that type.

###### vips_match

Scale, rotate and translate `sec` so that the tie-points line up.

###### vips_math

Perform various functions in -lm, the maths library, on images.

###### vips_math2

This operation calculates a 2-ary maths operation on a pair of images and writes the result to `out`. The images may have any non-complex format. `out` is float except in the case that either of `left` or `right` are double, in which case `out` is also double.

###### vips_math2_const

This operation calculates various 2-ary maths operations on an image and an array of constants and writes the result to `out`. The image may have any non-complex format. `out` is float except in the case that `in` is double, in which case `out` is also double.

###### vips_math2_const1

This operation calculates various 2-ary maths operations on an image and a constant. See `vips_math2_const()`.

###### vips_matrixinvert

This operation calculates the inverse of the matrix represented in `m`. The scale and offset members of the input matrix are ignored.

###### vips_matrixmultiply

Multiplies two matrix images.

###### vips_matrixprint

Print `in` to %stdout in matrix format. See `vips_matrixload()` for a description of the format.

###### vips_matrixsave

Write `in` to `filename` in matrix format. See `vips_matrixload()` for a description of the format.

###### vips_matrixsave_target

As `vips_matrixsave()`, but save to a target.

###### vips_max

This operation finds the maximum value in an image.

###### vips_maxpair

For each pixel, pick the maximum of a pair of images.

###### vips_measure

Analyse a grid of colour patches, producing an array of patch averages. The mask has a row for each measured patch and a column for each image band. The operations issues a warning if any patch has a deviation more than 20% of the mean. Only the central 50% of each patch is averaged.

###### vips_median

A convenience function equivalent to:.

###### vips_merge

This operation joins two images left-right (with `ref` on the left) or up-down (with `ref` above) with a smooth seam.

###### vips_min

This operation finds the minimum value in an image.

###### vips_image_minimise_all

Minimise memory use on this image and any upstream images, that is, images which this image depends upon. This function is called automatically at the end of a computation, but it might be useful to call at other times.

###### vips_minpair

For each pixel, pick the minimum of a pair of images.

###### vips_more

Perform `VIPS_OPERATION_RELATIONAL_MORE` on a pair of images. See `vips_relational()`.

###### vips_more_const

Perform `VIPS_OPERATION_RELATIONAL_MORE` on an image and a constant. See `vips_relational_const()`.

###### vips_more_const1

Perform `VIPS_OPERATION_RELATIONAL_MORE` on an image and a constant. See `vips_relational_const()`.

###### vips_moreeq

Perform `VIPS_OPERATION_RELATIONAL_MOREEQ` on a pair of images. See `vips_relational()`.

###### vips_moreeq_const

Perform `VIPS_OPERATION_RELATIONAL_MOREEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_moreeq_const1

Perform `VIPS_OPERATION_RELATIONAL_MOREEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_morph

Performs a morphological operation on `in` using `mask` as a structuring element.

###### vips_mosaic

This operation joins two images left-right (with `ref` on the left) or top-bottom (with `ref` above) given an approximate overlap.

###### vips_mosaic1

This operation joins two images top-bottom (with `sec` on the right) or left-right (with `sec` at the bottom) given an approximate pair of tie-points. `sec` is scaled and rotated as necessary before the join.

###### vips_msb

Turn any integer image to 8-bit unsigned char by discarding all but the most significant byte. Signed values are converted to unsigned by adding 128.

###### vips_multiply

This operation calculates `left` * `right` and writes the result to `out`.

###### vips_niftisave

Write a VIPS image to a file in NIFTI format.

###### vips_notequal

Perform `VIPS_OPERATION_RELATIONAL_NOTEQ` on a pair of images. See `vips_relational()`.

###### vips_notequal_const

Perform `VIPS_OPERATION_RELATIONAL_NOTEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_notequal_const1

Perform `VIPS_OPERATION_RELATIONAL_NOTEQ` on an image and a constant. See `vips_relational_const()`.

###### vips_orimage

Perform `VIPS_OPERATION_BOOLEAN_OR` on a pair of images. See `vips_boolean()`.

###### vips_orimage_const

Perform `VIPS_OPERATION_BOOLEAN_OR` on an image and an array of constants. See `vips_boolean_const()`.

###### vips_orimage_const1

Perform `VIPS_OPERATION_BOOLEAN_OR` on an image and a constant. See `vips_boolean_const1()`.

###### vips_percent

`vips_percent()` returns (through the `threshold` parameter) the threshold below which there are `percent` values of `in`. For example:.

###### vips_phasecor

Convert the two input images to Fourier space, calculate phase-correlation, back to real space.

###### vips_image_pio_input

Check that an image is readable with `vips_region_prepare()` and friends. If it isn’t, try to transform the image so that `vips_region_prepare()` can work.

###### vips_image_pio_output

Check that an image is writeable with `vips_image_generate()`. If it isn’t, try to transform the image so that `vips_image_generate()` can work.

###### vips_image_pipelinev

Build an array and call `vips_image_pipeline_array()`.

###### vips_pngsave

Write a VIPS image to a file as PNG.

###### vips_pngsave_buffer

As `vips_pngsave()`, but save to a memory buffer.

###### vips_pngsave_target

As `vips_pngsave()`, but save to a target.

###### vips_polar

Perform `VIPS_OPERATION_COMPLEX_POLAR` on an image. See `vips_complex()`.

###### vips_image_posteval

No description available.

###### vips_pow

Perform `VIPS_OPERATION_MATH2_POW` on a pair of images. See `vips_math2()`.

###### vips_pow_const

Perform `VIPS_OPERATION_MATH2_POW` on an image and a constant. See `vips_math2_const()`.

###### vips_pow_const1

Perform `VIPS_OPERATION_MATH2_POW` on an image and a constant. See `vips_math2_const()`.

###### vips_ppmsave

Write a VIPS image to a file as PPM.

###### vips_ppmsave_target

As `vips_ppmsave()`, but save to a target.

###### vips_image_preeval

No description available.

###### vips_premultiply

Premultiplies any alpha channel.

###### vips_prewitt

Prewitt edge detector.

###### vips_image_print_field

Prints field `name` to stdout as ASCII. Handy for debugging.

###### vips_profile

`vips_profile()` searches inward from the edge of `in` and finds the first non-zero pixel. Pixels in `columns` have the distance from the top edge to the first non-zero pixel in that column, `rows` has the distance from the left edge to the first non-zero pixel in that row.

###### vips_project

Find the horizontal and vertical projections of an image, ie. the sum of every row of pixels, and the sum of every column of pixels. The output format is uint, int or double, depending on the input format.

###### vips_quadratic

Transform an image with a 0, 1, 2, or 3rd order polynomial.

###### vips_rad2float

Unpack a RAD (`VIPS_CODING_RAD`) image to a three-band float image.

###### vips_radsave

Write a VIPS image in Radiance (HDR) format.

###### vips_radsave_buffer

As `vips_radsave()`, but save to a memory buffer.

###### vips_radsave_target

As `vips_radsave()`, but save to a target.

###### vips_rank

`vips_rank()` does rank filtering on an image. A window of size `width` by `height` is passed over the image. At each position, the pixels inside the window are sorted into ascending order and the pixel at position `index` is output. `index` numbers from 0.

###### vips_rawsave

Writes the pixels in `in` to the file `filename` with no header or other metadata.

###### vips_rawsave_buffer

As `vips_rawsave()`, but save to a memory buffer.

###### vips_rawsave_target

As `vips_rawsave()`, but save to a target.

###### vips_real

Perform `VIPS_OPERATION_COMPLEXGET_REAL` on an image. See `vips_complexget()`.

###### vips_recomb

This operation recombines an image’s bands. Each pixel in `in` is treated as an n-element vector, where n is the number of bands in `in`, and multiplied by the n x m matrix `m` to produce the m-band image `out`.

###### vips_rect

Perform `VIPS_OPERATION_COMPLEX_RECT` on an image. See `vips_complex()`.

###### vips_reduce

Reduce `in` by a pair of factors with a pair of 1D kernels.

###### vips_reduceh

Reduce `in` horizontally by a float factor.

###### vips_reducev

Reduce `in` vertically by a float factor.

###### vips_relational

Perform various relational operations on pairs of images.

###### vips_relational_const

Perform various relational operations on an image and an array of constants.

###### vips_relational_const1

Perform various relational operations on an image and a constant. See `vips_relational_const()`.

###### vips_remainder

This operation calculates `left` % `right` (remainder after integer division) and writes the result to `out`. The images may have any non-complex format. For float formats, `vips_remainder()` calculates `in1` - `in2` * floor (`in1` / `in2`).

###### vips_remainder_const

This operation calculates `in` % `c` (remainder after division by an array of constants) and writes the result to `out`. The image may have any non-complex format. For float formats, `vips_remainder_const()` calculates `in` - `c` * floor (`in` / `c`).

###### vips_remainder_const1

This operation calculates `in` % `c` (remainder after division by a constant) and writes the result to `out`. The image may have any non-complex format. For float formats, `vips_remainder_const()` calculates `in` - `c` * floor (`in` / `c`).

###### vips_remosaic

`vips_remosaic()` works rather as `vips_globalbalance()`. It takes apart the mosaiced image `in` and rebuilds it, substituting images.

###### vips_image_remove

Find and remove an item of metadata. Return `FALSE` if no metadata of that name was found.

###### vips_reorder_margin_hint

`vips_reorder_margin_hint()` sets a hint that `image` contains a margin, that is, that each `vips_region_prepare()` on `image` will request a slightly larger region from it’s inputs. A good value for `margin` is (width * height) for the window the operation uses.

###### vips_reorder_prepare_many

`vips_reorder_prepare_many()` runs `vips_region_prepare()` on each region in `regions`, requesting the pixels in `r`.

###### vips_replicate

Repeats an image many times.

###### vips_resize

Resize an image.

###### vips_rint

Round to an integral value with `VIPS_OPERATION_ROUND_RINT`. See `vips_round()`.

###### vips_rot

Rotate `in` by a multiple of 90 degrees.

###### vips_rot180

Rotate `in` by 180 degrees. A convenience function over `vips_rot()`.

###### vips_rot270

Rotate `in` by 270 degrees clockwise. A convenience function over `vips_rot()`.

###### vips_rot45

Rotate `in` by a multiple of 45 degrees. Odd-length sides and square images only.

###### vips_rot90

Rotate `in` by 90 degrees clockwise. A convenience function over `vips_rot()`.

###### vips_rotate

This operator calls `vips_affine()` for you, calculating the matrix for the affine transform from `scale` and `angle`.

###### vips_round

Round to an integral value.

###### vips_rshift

Perform `VIPS_OPERATION_BOOLEAN_RSHIFT` on a pair of images. See `vips_boolean()`.

###### vips_rshift_const

Perform `VIPS_OPERATION_BOOLEAN_LSHIFT` on an image and an array of constants. See `vips_boolean_const()`.

###### vips_rshift_const1

Perform `VIPS_OPERATION_BOOLEAN_RSHIFT` on an image and a constant. See `vips_boolean_const1()`.

###### vips_sRGB2HSV

Convert to HSV.

###### vips_sRGB2scRGB

Convert an sRGB image to scRGB.

###### vips_scRGB2BW

Convert an scRGB image to greyscale. Set `depth` to 16 to get 16-bit output.

###### vips_scRGB2XYZ

Turn XYZ to scRGB.

###### vips_scRGB2sRGB

Convert an scRGB image to sRGB. Set `depth` to 16 to get 16-bit output.

###### vips_scale

Search the image for the maximum and minimum value, then return the image as unsigned 8-bit, scaled so that the maximum value is 255 and the minimum is zero.

###### vips_scharr

Scharr edge detector.

###### vips_sequential

This operation behaves rather like `vips_copy()` between images `in` and `out`, except that it checks that pixels on `in` are only requested top-to-bottom. This operation is useful for loading file formats which are strictly top-to-bottom, like PNG.

###### vips_image_set

Set a piece of metadata on `image`. Any old metadata with that name is destroyed. The `GValue` is copied into the image, so you need to unset the value when you’re done with it.

###### vips_image_set_area

Attaches `data` as a metadata item on `image` under the name `name`. When VIPS no longer needs the metadata, it will be freed with `free_fn`.

###### vips_image_set_array_double

Attaches `array` as a metadata item on `image` as `name`. A convenience function over `vips_image_set()`.

###### vips_image_set_array_int

Attaches `array` as a metadata item on `image` as `name`. A convenience function over `vips_image_set()`.

###### vips_image_set_blob

Attaches `data` as a metadata item on `image` under the name `name`.

###### vips_image_set_blob_copy

Attaches `data` as a metadata item on `image` under the name `name`, taking a copy of the memory area.

###### vips_image_set_delete_on_close

Sets the delete_on_close flag for the image. If this flag is set, when `image` is finalized, the filename held in `image`->filename at the time of this call is deleted.

###### vips_image_set_double

Attaches `d` as a metadata item on `image` as `name`. A convenience function over `vips_image_set()`.

###### vips_image_set_image

Attaches `im` as a metadata item on `image` as `name`. A convenience function over `vips_image_set()`.

###### vips_image_set_int

Attaches `i` as a metadata item on `image` under the name `name`. A convenience function over `vips_image_set()`.

###### vips_image_set_kill

Set the `VipsImage`.kill flag on an image. Handy for stopping sets of threads.

###### vips_image_set_progress

Vips signals evaluation progress via the `VipsImage::preeval`, `VipsImage::eval` and `VipsImage::posteval` signals. Progress is signalled on the most-downstream image for which `vips_image_set_progress()` was called.

###### vips_image_set_string

Attaches `str` as a metadata item on `image` as `name`. A convenience function over `vips_image_set()` using `VIPS_TYPE_REF_STRING`.

###### vips_sharpen

Selectively sharpen the L channel of a LAB image. The input image is transformed to `VIPS_INTERPRETATION_LABS`.

###### vips_shrink

Shrink `in` by a pair of factors with a simple box filter.

###### vips_shrinkh

Shrink `in` horizontally by an integer factor. Each pixel in the output is the average of the corresponding line of `hshrink` pixels in the input.

###### vips_shrinkv

Shrink `in` vertically by an integer factor.

###### vips_sign

Finds the unit vector in the direction of the pixel value. For non-complex images, it returns a signed char image with values -1, 0, and 1 for negative, zero and positive pixels. For complex images, it returns a complex normalised to length 1.

###### vips_similarity

This operator calls `vips_affine()` for you, calculating the matrix for the affine transform from `scale` and `angle`. Other parameters are passed on to `vips_affine()` unaltered.

###### vips_sin

Perform `VIPS_OPERATION_MATH_SIN` on an image. See `vips_math()`.

###### vips_sinh

Perform `VIPS_OPERATION_MATH_SINH` on an image. See `vips_math()`.

###### vips_sink

Loops over an image. `generate_fn` is called for every pixel in the image, with the `reg` argument being a region of calculated pixels. `vips_sink()` is used to implement operations like `vips_avg()` which have no image output.

###### vips_sink_disc

`vips_sink_disc()` loops over `im`, top-to-bottom, generating it in sections. As each section is produced, `write_fn` is called.

###### vips_sink_screen

This operation renders `in` in the background, making pixels available on `out` as they are calculated. The `notify_fn` callback is run every time a new set of pixels are available. Calculated pixels are kept in a cache with tiles sized `tile_width` by `tile_height` pixels and with at most `max_tiles` tiles. If `max_tiles` is -1, the cache is of unlimited size (up to the maximum image * size). The `mask` image is a one-band uchar image and has 255 for pixels which are currently in cache and 0 for uncalculated pixels.

###### vips_sink_tile

Loops over an image. `generate_fn` is called for every pixel in the image, with the `reg` argument being a region of calculated pixels.

###### vips_smartcrop

Crop an image down to a specified width and height by removing boring parts.

###### vips_sobel

Sobel edge detector.

###### vips_spcor

Calculate a correlation surface.

###### vips_spectrum

Make a displayable (ie. 8-bit unsigned int) power spectrum.

###### vips_stats

Find many image statistics in a single pass through the data. `out` is a one-band `VIPS_FORMAT_DOUBLE` image of at least 10 columns by n + 1 (where n is number of bands in image `in`) rows. Columns are statistics, and are, in order: minimum, maximum, sum, sum of squares, mean, standard deviation, x coordinate of minimum, y coordinate of minimum, x coordinate of maximum, y coordinate of maximum. Later versions of `vips_stats()` may add more columns.

###### vips_stdif

`vips_stdif()` performs statistical differencing according to the formula given in page 45 of the book “An Introduction to Digital Image Processing” by Wayne Niblack.

###### vips_subsample

Subsample an image by an integer fraction. This is fast, nearest-neighbour shrink.

###### vips_subtract

This operation calculates `in1` - `in2` and writes the result to `out`.

###### vips_tan

Perform `VIPS_OPERATION_MATH_TAN` on an image. See `vips_math()`.

###### vips_tanh

Perform `VIPS_OPERATION_MATH_TANH` on an image. See `vips_math()`.

###### vips_thumbnail_image

Exactly as `vips_thumbnail()`, but read from an existing image.

###### vips_tiffsave

Write a VIPS image to a file as TIFF.

###### vips_tiffsave_buffer

As `vips_tiffsave()`, but save to a memory buffer.

###### vips_tiffsave_target

As `vips_tiffsave()`, but save to a target.

###### vips_tilecache

This operation behaves rather like `vips_copy()` between images `in` and `out`, except that it keeps a cache of computed pixels. This cache is made of up to `max_tiles` tiles (a value of -1 means any number of tiles), and each tile is of size `tile_width` by `tile_height` pixels.

###### vips_transpose3d

Transpose a volumetric image.

###### vips_unpremultiply

Unpremultiplies any alpha channel.

###### vips_vipssave

Write `in` to `filename` in VIPS format.

###### vips_vipssave_target

As `vips_vipssave()`, but save to a target.

###### vips_webpsave

Write an image to a file in WebP format.

###### vips_webpsave_buffer

As `vips_webpsave()`, but save to a memory buffer.

###### vips_webpsave_mime

As `vips_webpsave()`, but save as a mime webp on stdout.

###### vips_webpsave_target

As `vips_webpsave()`, but save to a target.

###### vips_image_wio_input

Check that an image is readable via the `VIPS_IMAGE_ADDR()` macro, that is, that the entire image is in memory and all pixels can be read with `VIPS_IMAGE_ADDR()`. If it isn’t, try to transform it so that `VIPS_IMAGE_ADDR()` can work.

###### vips_wop

Perform `VIPS_OPERATION_MATH2_WOP` on a pair of images. See `vips_math2()`.

###### vips_wop_const

Perform `VIPS_OPERATION_MATH2_WOP` on an image and a constant. See `vips_math2_const()`.

###### vips_wop_const1

Perform `VIPS_OPERATION_MATH2_WOP` on an image and a constant. See `vips_math2_const()`.

###### vips_wrap

Slice an image up and move the segments about so that the pixel that was at 0, 0 is now at `x`, `y`.

###### vips_image_write

Write `image` to `out`. Use `vips_image_new()` and friends to create the `VipsImage` you want to write to.

###### vips_image_write_line

Write a line of pixels to an image. This function must be called repeatedly with `ypos` increasing from 0 to `VipsImage:height`. `linebuffer` must be `VIPS_IMAGE_SIZEOF_LINE()` bytes long.

###### vips_image_write_prepare

Call this after setting header fields (width, height, and so on) to allocate resources ready for writing.

###### vips_image_write_to_buffer

Writes `in` to a memory buffer in a format specified by `suffix`.

###### vips_image_write_to_file

Writes `in` to `name` using the saver recommended by `vips_foreign_find_save()`.

###### vips_image_write_to_memory

Writes `in` to memory as a simple, unformatted C-style array.

###### vips_image_write_to_target

Writes `in` to `output` in format `suffix`.

###### vips_zoom

Zoom an image by repeating pixels. This is fast nearest-neighbour zoom.

##### Methods inherited from VipsObject (27)

Please see VipsObject for a full list of methods.

##### Methods inherited from GObject (43)

Please see GObject for a full list of methods.

#### Properties

###### Vips.Image:bands

No description available.

###### Vips.Image:coding

No description available.

###### Vips.Image:demand

No description available.

###### Vips.Image:filename

No description available.

###### Vips.Image:foreign-buffer

No description available.

###### Vips.Image:format

No description available.

###### Vips.Image:height

No description available.

###### Vips.Image:interpretation

No description available.

###### Vips.Image:kill

No description available.

###### Vips.Image:mode

No description available.

###### Vips.Image:sizeof-header

No description available.

###### Vips.Image:width

No description available.

###### Vips.Image:xoffset

No description available.

###### Vips.Image:xres

No description available.

###### Vips.Image:yoffset

No description available.

###### Vips.Image:yres

No description available.

##### Properties inherited from VipsObject (2)

###### Vips.Object:description

No description available.

###### Vips.Object:nickname

No description available.

#### Signals

###### Vips.Image::eval

This signal is emitted once per work unit (typically a 128 x 128 area of pixels) during image computation.

###### Vips.Image::invalidate

This signal is emitted when an image or one of it’s upstream data sources has been destructively modified. See `vips_image_invalidate_all()`.

###### Vips.Image::minimise

This signal is emitted when an image has been asked to minimise memory usage. All non-essential caches are dropped. See `vips_image_minimise_all()`.

###### Vips.Image::posteval

This signal is emitted once at the end of the computation of `image`. It’s a good place to shut down evaluation feedback.

###### Vips.Image::preeval

This signal is emitted once before computation of `image` starts. It’s a good place to set up evaluation feedback.

###### Vips.Image::written

This signal is emitted just after an image has been written to. It is used by vips to implement things like write to foreign file formats.

##### Signals inherited from VipsObject (4)

###### VipsObject::close

The ::close signal is emitted once during object close. The object is dying and may not work.

###### VipsObject::postbuild

The ::postbuild signal is emitted once just after successful object construction. Return non-zero to cause object construction to fail.

###### VipsObject::postclose

The ::postclose signal is emitted once after object close. The object pointer is still valid, but nothing else.

###### VipsObject::preclose

The ::preclose signal is emitted once just before object close starts. The object is still alive.

##### Signals inherited from GObject (1)

###### GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

#### Class structure

    struct VipsImageClass {
      VipsObjectClass parent_class;
      void (* preeval) (
        VipsImage* image,
        VipsProgress* progress,
        void* data
      );
      void (* eval) (
        VipsImage* image,
        VipsProgress* progress,
        void* data
      );
      void (* posteval) (
        VipsImage* image,
        VipsProgress* progress,
        void* data
      );
      void (* written) (
        VipsImage* image,
        int* result,
        void* data
      );
      void (* invalidate) (
        VipsImage* image,
        void* data
      );
      void (* minimise) (
        VipsImage* image,
        void* data
      );

    }

No description available.

###### Class members

`parent_class: VipsObjectClass`

  No description available.

`preeval: void (* preeval) ( VipsImage* image, VipsProgress* progress, void* data )`

  No description available.

`eval: void (* eval) ( VipsImage* image, VipsProgress* progress, void* data )`

  No description available.

`posteval: void (* posteval) ( VipsImage* image, VipsProgress* progress, void* data )`

  No description available.

`written: void (* written) ( VipsImage* image, int* result, void* data )`

  No description available.

`invalidate: void (* invalidate) ( VipsImage* image, void* data )`

  No description available.

`minimise: void (* minimise) ( VipsImage* image, void* data )`

  No description available.

#### Virtual methods

###### Vips.ImageClass.eval

No description available.

###### Vips.ImageClass.invalidate

No description available.

###### Vips.ImageClass.minimise

No description available.

###### Vips.ImageClass.posteval

No description available.

###### Vips.ImageClass.preeval

No description available.

###### Vips.ImageClass.written

No description available.