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): bool

    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

    Returns true on success or false on failure.

    Changelog

    VersionDescription
    8.0.0image expects a GdImage instance now; previously, a valid gdresource 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 and free image
    imagegif($im, './php_gamma_corrected.gif');
    imagedestroy($im);
    ?>
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