ændre baggrundsfarve på png

Hvis det er PNG der er tale om, kunne jeg godt tænke mig at man kan ændre baggrunden til en farve.

Håber i kan hjælpe.

mvh

Henrik

--------------------------------------------------------

<?php
//http://www.eksperten.dk/spm/812550

$imgName = $_GET['src'];

if(preg_match('/\.(:?jpeg|jpe|jpg)$/i', $imgName))
    $imgImport = imagecreatefromjpeg($imgName);
elseif(preg_match('/\.(:?png)$/i', $imgName))
    $imgImport = imagecreatefrompng($imgName);
elseif(preg_match('/\.(:?gif)$/i', $imgName))
    $imgImport = imagecreatefromgif($imgName);   
else {
    header ("Content-type: image/png");
    $im = @imagecreatetruecolor(120, 20) or die("Cannot Initialize new GD image stream");
    $text_color = imagecolorallocate($im, 233, 14, 91);
    imagestring($im, 1, 5, 5, "ERROR", $text_color);
    imagepng($im);
    imagedestroy($im);
    exit();
}


$imgName_w = imagesx($imgImport);
$imgName_h = imagesy($imgImport);

$gradientHeight = 100;

// Create new blank image with sizes.
$background = imagecreatetruecolor($imgName_w, $gradientHeight);

$gradientColor = "0 0 0"; //White
$gradparts = explode(" ",$gradientColor); // get the parts of the  colour (RRR,GGG,BBB)
$dividerHeight = 1;

$gradient_y_startpoint = $dividerHeight;
$gdGradientColor=ImageColorAllocate($background,$gradparts[0],$gradparts[1],$gradparts[2]);

$newImage = imagecreatetruecolor($imgName_w, $imgName_h);
for ($x = 0; $x < $imgName_w; $x++){
    for ($y = 0; $y < $imgName_h; $y++){
        imagecopy($newImage, $imgImport, $x, $imgName_h - $y - 1, $x, $y, 1, 1);
    }
}
// Add it to the blank background image
imagecopymerge ($background, $newImage, 0, 0, 0, 0, $imgName_w, $imgName_h, 100);

//create from a the image so we can use fade out.
$gradient_line = imagecreatetruecolor($imgName_w, 1);

// Next we draw a GD line into our gradient_line
imageline ($gradient_line, 0, 0, $imgName_w, 0, $gdGradientColor);

$i = 0;
$transparency = 30; //from 0 - 100

while ($i < $gradientHeight){ //create line by line changing as we go
    imagecopymerge ($background, $gradient_line, 0,$gradient_y_startpoint, 0, 0, $imgName_w, 1, $transparency);
    ++$i;
    ++$gradient_y_startpoint;
             
    if ($transparency == 100){
        $transparency = 100;
    }else{
        // this will determing the height of the
        //reflection. The higher the number, the smaller the reflection.
        //1 being the lowest(highest reflection)
        $transparency = $transparency + 1;
    }
}

//New blank image, wetfloor effect image + original image.
$output = imagecreatetruecolor($imgName_w, $imgName_h + $gradientHeight);

//Copy original image
imagecopy($output, $imgImport, 0, 0, 0, 0, $imgName_w, $imgName_h);

// Set the thickness of the line we're about to draw
imagesetthickness($background, 3);

// Draw the line - me do not likey the liney
imageline($background, 0, 0, $imgName_w, 0, $gdGradientColor);

//Copy wetfloor image
imagecopy($output, $background, 0, $imgName_h, 0, 0, $imgName_w, $gradientHeight);

header("Content-type: image/jpeg");

imagejpeg($output, NULL, 100); //100 being the quality of image 100 Max(Best)
imagedestroy($background);
imagedestroy($gradient_line);
imagedestroy($newImage);
imagedestroy($output);

?>