Vips.Image.mask_ideal_ring
Description: Reference for Vips.Image.mask_ideal_ring

### Constructor

# Vips Imagemask_ideal_ring

#### Declaration [src]

    int
    vips_mask_ideal_ring (
      VipsImage** out,
      int width,
      int height,
      double frequency_cutoff,
      double ringwidth,
      ...
    )

#### Description [src]

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.

Optional arguments

- `nodc`: `gboolean`, don’t set the DC pixel
- `reject`: `gboolean`, invert the filter sense
- `optical`: `gboolean`, coordinates in optical space
- `uchar`: `gboolean`, output a uchar image

See also

`vips_mask_ideal()`.

This constructor is not directly available to language bindings.

#### Parameters

`out`

  Type: `VipsImage`

  Output image.

  The argument will be set by the function.
  The caller of the function takes ownership of the returned data, and is responsible for freeing it.

`width`

  Type: `int`

  Image size.

`height`

  Type: `int`

  Image size.

`frequency_cutoff`

  Type: `double`

  Threshold at which filter ends.

`ringwidth`

  Type: `double`

  Ring width.

`...`

  Type: ``

  `NULL`-terminated list of optional named arguments.

#### Return value

Type: `int`

0 on success, -1 on error.