This function, along with other functions, is good for color manipulation inside a dynamic image. imagecolorclosest() lets you specify a custom color, and the function searches for and returns the closest match it can find in the color palette. It's not useful in a function such as imagecolortransparent() , but can be used for other purposes such as determining whether the base image contains a required range of color without actually needing the exact color.
Example 395. Get the actual color closest to the desired color from an image
header("Content-type: image/png"); $im = imagecreate(200, 200); $red = imagecolorallocate($im, 255, 0, 0); // create a shade of blue $offblue = imagecolorallocate($im, 90, 90, 200); imagefill($im, 0, 0, $red); imagefilledrectangle($im, 10, 10, 40, 40, $offblue); // get closest color to actual blue from image $newblue = imagecolorclosest($im, 0, 0, 255); imagefilledrectangle($im, 100, 100, 140, 140, $newblue); imagepng($im); imagedestroy($im);
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