imagepalettetotruecolor

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

imagepalettetotruecolor — Converts a palette based image to true color

说明

imagepalettetotruecolor(GdImage $image): bool

Converts a palette based image, created by functions like imagecreate() to a true color image, like imagecreatetruecolor().

参数

image: 由图象创建函数(例如imagecreatetruecolor())返回的图象资源。

返回值

Returns true if the convertion was complete, or if the source image already is a true color image, otherwise false is returned.

更新日志

版本	说明
8.0.0	`image` expects a GdImage instance now; previously, a resource was expected.

范例

示例 #1 Converts any image object to true color

<?php 
// Backwards compatiblityif(!function_exists('imagepalettetotruecolor')){
    function imagepalettetotruecolor(&$src)    {
        if(imageistruecolor($src))        {
            return(true);
        }
        $dst = imagecreatetruecolor(imagesx($src), imagesy($src));
        imagecopy($dst, $src, 0, 0, 0, 0, imagesx($src), imagesy($src));
        imagedestroy($src);
        $src = $dst;
        return(true);
    }
}
// Helper closure$typeof = function() use($im){
    echo 'typeof($im) = ' . (imageistruecolor($im) ? 'true color' : 'palette'), PHP_EOL;
}
;
// Create a palette based image$im = imagecreate(100, 100);
$typeof();
// Convert it to true colorimagepalettetotruecolor($im);
$typeof();
// Free the memoryimagedestroy($im);
?>

以上例程会输出：

typeof($im) = palette
typeof($im) = true color

参见

imagecreatetruecolor() - 新建一个真彩色图像
imageistruecolor() - 检查图像是否为真彩色图像

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