imagegammacorrect

(PHP 4, PHP 5, PHP 7, PHP 8)

imagegammacorrect — Apply a gamma correction to a GD image

Description

imagegammacorrect(GdImage $image, float $input_gamma, float $output_gamma): true

Applies gamma correction to the given gd image given an input and an output gamma.

Parameters

image

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

input_gamma

The input gamma.

output_gamma

The output gamma.

Return Values

Always returns true.

Changelog

VersionDescription
8.0.0image expects a GdImage instance now; previously, a valid gd resource was expected.

Examples

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');
?>