Transforms input image into a gray-level image. The intensity of
each pixel in the output image reflects the distance between a
reference color and the color of the pixel in the RGB color space.
The lower the intensity, the closer the pixel matches the reference
color. If the invert flag is
true, higher intensity means
closer match. If the input is a gray-level image, all color
channels are assumed to be identical and equal to the intensity of
image: Input image.
referenceColor: The color to which differences are calculated.
invert: Inversion flag. If this value is
true, smaller intensity in the output image indicates greater color distance. If invert is
true, 255 indicates a perfect match.
normalize: Color intensity normalization flag. If this value is
true, intensities of the RGB components of both the reference color and colors of the pixels in the input image are normalized before distance calculation. The removes the effect of varying brightness due to e.g. uneven lighting or light drop-off towards the edge of the field of view. This flag has no effect if the input is a gray-level image.
image: Absolute color distances. If invert is
false, lower intensity means shorter distance to referenceColor. If invert is
true, brighter intensity means a better match.