imagegammacorrect() is an inbuilt function in PHP that is used to apply a gamma correction to a given Graphics Draw (GD) input image and an output gamma.
Syntax
bool imagegammacorrect(resource $image, float $inputgamma, float $outputgamma)
Parameters
imagegammacorrect() takes three different parameters: $image, $inputgamma and $outputgamma.
$image − Specifies the image to be worked.
$inputgamma − Specifies the input gamma.
$outputgamma − Specifies the output gamma.
Return Values
imagegammacorrect() returns True on success and False on failure.
Example 1
<?php
// load an image from the local drive folder
$img = imagecreatefrompng('C:\xampp\htdocs\Images\img58.png');
// Change the image gamma by using imagegammacorrect
imagegammacorrect($img, 15, 1.5);
// Output image to the browser
header('Content-Type: image/png');
imagepng($img);
imagedestroy($img);
?>Output
Input image before using imagegammacorrect() PHP function
Output image after using imagegammacorrect() PHP function
Explanation − In this example, we loaded the image from the local drive folder by using the imagecreatefrompng() function or we can also use the URL of an image. After that, we applied imagegammacorrect() with the values 5 and 1.5. We can see the difference between the two images in the output.