Vips.Image.mask_ideal (original) (raw)

Constructor

VipsImagemask_ideal

Declaration [src]

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

Description [src]

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.

This operation creates a one-band float image of the specified size. The image has values in the range [0, 1] and is typically used for multiplying against frequency domain images to filter them. Masks are created with the DC component at (0, 0). The DC pixel always has the value 1.0.

Set nodc to not set the DC pixel.

Set optical to position the DC component in the centre of the image. This makes the mask suitable for multiplying against optical Fourier transforms. See vips_wrap().

Set reject to invert the sense of the filter. For example, low-pass becomes low-reject.

Set uchar to output an 8-bit unsigned char image rather than a float image. In this case, pixels are in the range [0 - 255].

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

This constructor is not directly available to language bindings.

Parameters

out

Type: VipsImage

Output image.

width

Type: int

Image size.

height

Type: int

Image size.

frequency_cutoff

Type: double

Threshold at which filter ends.

...

Type: ``

NULL-terminated list of optional named arguments.

Return value

Type: int

0 on success, -1 on error.