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imagecolorset
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imagecolorset

Name

imagecolorset — Replaces one color with another color.

Synopsis

bool imagecolorset(image, color, red, green, blue); int image: Image identifier int color: Color to change int red: Red component of new color int green: Green component of new color int blue: Blue component of new color

Returns

TRUE on success; FALSE on error

Description

Changes one color already in an image to a new specified color. Useful for replacing a block of color in an image without having to do any possibly complex redrawing operations. In the following example, the closest blue is found in the image using imagecolorclosest() and then replaced with green. This demonstrates how a color doesn't even need to be known exactly to be replaced.

Example

Example 400. Replace blue with green

header("Content-type: image/png");
$im = imagecreate(200, 200);
$red = imagecolorallocate($im, 255, 0, 0);
$offblue = imagecolorallocate($im, 90, 90, 200);
imagefill($im, 0, 0, $red);
imagefilledrectangle($im, 10, 10, 40, 40, $offblue);
// above could come from an uploaded image
// find a blue in the image
$newblue = imagecolorclosest($im, 0, 0, 255);
// change it to green
imagecolorset($im, $newblue, 0, 255, 0);
imagepng($im);
imagedestroy($im);

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