(PHP 4, PHP 5, PHP 7, PHP 8)
imagegammacorrect — Apply a gamma correction to a GD image
imagegammacorrect(GdImage $image, float $input_gamma, float $output_gamma): bool
Applies gamma correction to the given gd image given an input and an output gamma.
image
A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
input_gammaThe input gamma.
output_gammaThe output gamma.
| Version | Description |
|---|---|
| 8.0.0 | image expects a GdImage instance now; previously, a valid gd resource was expected. |
Example #1 imagegammacorrect() usage
<?php
// Create image instance
$im = imagecreatefromgif('php.gif');
// Correct gamma, out = 1.537
imagegammacorrect($im, 1.0, 1.537);
// Save
imagegif($im, './php_gamma_corrected.gif');
?>
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https://www.php.net/manual/en/function.imagegammacorrect.php