Help with GD and changing the color of an image

[ladymeow]

I'm trying to come up with a script that will change the color of a transparent png to a new color. Like #FF0000 to #0000FF. The images I'm using are solid color with a transparent background. Anyways it's not going so well. I have this script that works for palpated images but when I try to use it with an image that has alpha transparency it gets all weird on me and shows up as solid blocks of color.

 

<?php
   $pic = imagecreatefrompng("base.png");
   $colorToChange = "FF0000";
   $newColor = "0000FF";

   $c1 = sscanf($colorToChange,"%2x%2x%2x");
   $c2 = sscanf($newColor ,"%2x%2x%2x");

   $cIndex = imagecolorexact($pic,$c1[0],$c1[1],$c1[2]);
   imagecolorset($pic,$cIndex,$c2[0],$c2[1],$c2[2]);

   header("Content-Type: image/png");
   imagepng($image);
   imagedestroy($image);
?> 

 

I want to be able to change the color of a png image that has alpha transparency so that I can keep the soft line rather then having a pixilated edge. Is this even possible to do with PHP? Please help point me in the right direction. I'm very new to GD and PHP.

[gerkintrigg]

Could you not isolate the alpha channel value for each pixel and turn it up to 100%. If the alpha value is less than 50% (for example) then replace the colour with white at 100%?

 

Then create a loop to do this for every pixel and you'll have a new image that you could create as a JPG if necessary.