GD and Image 函数
PHP Manual

imagepalettetotruecolor

(PHP 5 >= 5.5.0)

imagepalettetotruecolorConverts a palette based image to true color

说明

bool imagepalettetotruecolor ( resource $src )

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.

范例

Example #1 Converts any image resource to true color

<?php
// Backwards compatiblity
if(!function_exists('imagepalettetotruecolor'))
{
    function 
imagepalettetotruecolor(&$src)
    {
        if(
imageistruecolor($src))
        {
            return(
true);
        }

        
$dst imagecreatetruecolor(imagesx($src), imagesy($src));

        
imagecopy($dst$src0000imagesx($src), imagesy($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(100100);
$typeof();

// Convert it to true color
imagepalettetotruecolor($im);
$typeof();

// Free the memory
imagedestroy($im);
?>

以上例程会输出:

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

参见


GD and Image 函数
PHP Manual