Image Processing Reference
(Reduce to a limited
set of colors)
This tool can gradually reduce the number of colors
in an image or harmonize the colors. You might find
it helpful when converting a photograph for screen
printing or when vectorizing the image.
One click on Desaturate turns a color image
into a grayscale image (black-and-white photo).
The command can be used on one layer of a
multilayered image. The image remains in the
RGB color space, so it isn't a real grayscale image
with just 256 colors. Therefore, the image can be
Intended for the developing of scanned color
negatives or altering a color photo into it´s negative.
Generally speaking, the command reverses the color
values and the brightness of the image or the layer.
Dark colors appear light and the colors are substituted
by complementary colors.
Reverses the pixels brightness values of the active layer
or the selected area. The color value and saturation
should be kept the same. Nevertheless, when the
image is rendered or when the tool is applied several
times, the colors can appear offset.
Offers a couple of automatic corrections, essentially,
one-click rendering to improve the contrast or colors.
Equalize adjusts the brightness values so that they
are equally dispersed. The curve of the histogram
is flattened, so to speak. Either the contrast of the
image or levels is raised and thereby improved or the
opposite occurs and the result is very bad. With dull
pictures, it is worth a try.
Auto: White Balance
White Balance recalibrates the colors automatically. It
is especially useful for images that contain a off-white
Normalize renders the image or layer so that the
darkest pixels are automatically set to black and the
brightest to almost white. This replaces the color
correction and is suitable for dull images lacking