PHP. Руководство по PHP. 2005
imagecolorclosest
imagecolorclosest
Description
int imagecolorclosest (resource image, int red, int green, int blue)Returns the index of the color in the palette of the image which is "closest" to the specified RGB value.
The "distance" between the desired color and each color in the palette is calculated as if the RGB values represented points in three-dimensional space.
If you created the image from a file, only colors used in the image are resolved. Colors present only in the pallete are not resolved.
See also imagecolorexact().
imagecolorat
imagecolorclosestalpha
