Method

VipsImagemorph

Declaration [src]

int
vips_morph (
  VipsImage* in,
  VipsImage** out,
  VipsImage* mask,
  VipsOperationMorphology morph,
  ...
)

Description [src]

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

The image should have 0 (black) for no object and 255 (non-zero) for an object. Note that this is the reverse of the usual convention for these operations, but more convenient when combined with the boolean operators. The output image is the same size as the input image: edge pxels are made by expanding the input image as necessary.

Mask coefficients can be either 0 (for object) or 255 (for background) or 128 (for do not care). The origin of the mask is at location (m.xsize / 2, m.ysize / 2), integer division. All algorithms have been based on the book “Fundamentals of Digital Image Processing” by A. Jain, pp 384-388, Prentice-Hall, 1989.

For #VIPS_OPERATION_MORPHOLOGY_ERODE, the whole mask must match for the output pixel to be set, that is, the result is the logical AND of the selected input pixels.

For #VIPS_OPERATION_MORPHOLOGY_DILATE, the output pixel is set if any part of the mask matches, that is, the result is the logical OR of the selected input pixels.

See the boolean operations vips_andimage(), vips_orimage() and vips_eorimage() for analogues of the usual set difference and set union operations.

Operations are performed using the processor’s vector unit, if possible. Disable this with --vips-novector or VIPS_NOVECTOR or vips_vector_set_enabled().

This method is not directly available to language bindings.