PHP 7.0.6 Released

    imagepalettetotruecolor

    (PHP 5 >= 5.5.0, PHP 7)

    imagepalettetotruecolor — Converts a palette based image to true color

    Description

    bool imagepalettetotruecolor ( resource $src )

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

    Parameters

    image

    An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().

    Return Values

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

    Examples

    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, $src, 0, 0, 0, 0, imagesx($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 color
    imagepalettetotruecolor($im);
    $typeof();

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

    The above example will output:

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

    See Also

    User Contributed Notes

    Polda18
    2 years ago
    PHP ver 5.4.24 does not support this function (it has not been defined). To get rid of this, you must copy image resource to new image created by function imagecreatetruecolor();

    Example with image loaded from GIF file:

    $image  = imagecreatefromgif("path/to/gif/file.gif");  //create an image from GIF
    $width  = imagesx($image);                             //get width of source image
    $height = imagesy($image);                             //get height of source image
    $image2 = imagecreatetruecolor($width,$height);        //create new image of true colors with given width and height
    imagecopy($image2,$image,0,0,0,0,$width,$height);      //copy source image to new one

    header("Content-Type: image/jpeg");                    //set header for JPG image
    imagejpg($image2);                                     //render JPg image into browser

    imagedestroy($image);                                  //free up memory
    imagedestroy($image2);
    walf
    2 years ago
    The backwards compatibility example does not preserve transparency. You must first wipe out the default black background on the new image:

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

                $dst = imagecreatetruecolor(imagesx($src), imagesy($src));
           
                imagealphablending($dst, false);//prevent blending with default black
                $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);//change the RGB values if you need, but leave alpha at 127
                imagefilledrectangle($dst, 0, 0, $imagesx($src), imagesy($src), $transparent);//simpler than flood fill
                imagealphablending($dst, true);//restore default blending

                imagecopy($dst, $src, 0, 0, 0, 0, imagesx($src), imagesy($src));
                imagedestroy($src);

                $src = $dst;
            return     true;
        }
    }
    ?>
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