Set the color for the specified palette index
Syntax
imagecolorset(
GdImage $image,
int $color,
int $red,
int $green,
int $blue,
int $alpha = 0
): ?falseParameters
imageA GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
colorAn index in the palette.
redValue of red component.
greenValue of green component.
blueValue of blue component.
alphaValue of alpha component.
Return
The function returns null on success, or false on failure.
Examples
1 · image color red green blue
<? $width = 100; $height = 100; $image = imagecreate($width, $height); $red = 0; $green = 0; $blue = 0; imagecolorallocate($image, $red, $green, $blue); $x = 0; $y = 0; $color = imagecolorat($image, $x, $y); $red = 255; $green = 255; $blue = 255; $return = imagecolorset($image, $color, $red, $green, $blue); var_export($return); ?>
NULL
2 · alpha
<? $width = 100; $height = 100; $image = imagecreate($width, $height); $red = 0; $green = 0; $blue = 0; imagecolorallocate($image, $red, $green, $blue); $x = 0; $y = 0; $color = imagecolorat($image, $x, $y); $red = 255; $green = 255; $blue = 255; $alpha = 64; $return = imagecolorset($image, $color, $red, $green, $blue, $alpha); var_export($return); ?>
NULL
3 · base64
<?
$width = 100;
$height = 100;
$image = imagecreate($width, $height);
$red = 0;
$green = 0;
$blue = 0;
imagecolorallocate($image, $red, $green, $blue);
$x = 0;
$y = 0;
$color = imagecolorat($image, $x, $y);
$red = 255;
$green = 255;
$blue = 255;
$alpha = 64;
imagecolorset($image, $color, $red, $green, $blue, $alpha);
ob_start();
imagepng($image);
$output = ob_get_clean();
echo '<!doctype html>
<html>
<body>
<img src="data:image/png;base64,' . base64_encode($output) . '">
</body>
</html>';
?><!doctype html>
<html>
<body>
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAGQAAABkAQMAAABKLAcXAAAAA1BMVEX///+nxBvIAAAAAXRSTlN+91uEXQAAAAlwSFlzAAAOxAAADsQBlSsOGwAAABRJREFUOI1jYBgFo2AUjIJRQE8AAAV4AAH5pV7HAAAAAElFTkSuQmCC">
</body>
</html>
