imagegammacorrect

(PHP 4, PHP 5)

imagegammacorrect — Apply a gamma correction to a GD image

Descrizione

bool imagegammacorrect ( resource $image , float $inputgamma , float $outputgamma )

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

Elenco dei parametri

image: Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().
inputgamma: The input gamma.
outputgamma: The output gamma.

Valori restituiti

Restituisce TRUE in caso di successo, FALSE in caso di fallimento.

Esempi

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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brian dot duncan at fife dot co dot uk ¶

11 years ago


Just thought I'd add how I used the gamma correction function (seeing as no-one had done so previously).  works great.



I used a form which has a parameter $GAMMA, so I usually type in something like 1.6



$image = ImageCreateFromJpeg ( "pictures/".$PICTURE2 ) ;

if ($GAMMA != "")

{

    $GammaFloat = (double) $GAMMA ;

    imagegammacorrect ($image, 1.0, $GammaFloat ) ;

        // now save the file

    imagejpeg ( $image, "pictures/"."$PICTURE2", 90 ) ;

}

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