GD and Image 函数
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imagegammacorrect

(PHP 4, PHP 5)

imagegammacorrect对 GD 图像应用 gamma 修正

说明

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

imagegammacorrect() 函数用给定的输入 gamma 值 inputgamma 和输出 gamma 值 outputgamma 对一幅 GD 图像流(image)应用 gamma 修正。


GD and Image 函数
在线手册:中文 英文
PHP手册
PHP手册 - N: 对 GD 图像应用 gamma 修正

用户评论:

brian dot duncan at fife dot co dot uk (26-Jan-2002 01:46)

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 ) ;
}