Milestone changed to Elgg 1.8.1 by ewinslow on 41199884-08-12

trac user twall wrote on 41347185-02-25

At first I looked at doing this by overriding the mod/profile upload actions (which have moved in 1.8), but that leaves un-fixed group icons and any other similar operations which might implement their own actions. So I looked to see if I could make a fix in a more central location.

The image resizing in filestore discards transparency information in converting to jpg.

Here is a partial solution to preserve transparency in filestore.php:get_resized_image_from_existing_file:

Insert this code immediately before the call to imagecopyresampled:

        // preserve transparency information, if any                            
        $trans = imagecolortransparent($original_image);
        $newsize = $params['newwidth'] * $params['newheight'];
        if ($trans >= 0) {
          $tc = imagecolorsforindex($original_image, $trans);
          $ti = imagecolorallocate($new_image, $tc['red'], $tc['green'], $tc['b\
lue']);
          imagefill($new_image, 0, 0, $ti);
          imagecolortransparent($new_image, $ti);
          $use_png = true;
        }
        // heuristic to use transparency only with icons/avatars                
        else if ($newsize <= 200*200) {
          // NOTE: most PNGs with transparency end up here                      
          imagealphablending($new_image, false);
          $color = imagecolorallocatealpha($new_image, 0, 0, 0, 127);
          imagefill($new_image, 0, 0, $color);
          imagesavealpha($new_image, true);
          $use_png = true;
        }

and then instead of always outputting jpeg:

        if ($use_png)
          imagepng($new_image);
        else
          // end famos                                                          
          imagejpeg($new_image, NULL, 90);

I haven't checked whether any callers of this function depend on the result being in jpeg format. I've also arbitrarily limited the size to 200x200, since you'll probably want jpeg for larger images, which aren't as likely as icons to have transparency.

Anyhow, the above patches work to allow transparency in uploaded user and group icons.

cash wrote on 41431226-06-23

Elgg needs a standard way to handle images (including routing without the full engine being loaded). I'm thinking that we can use something like the new cache handler that we added in 1.8.

@hypeJunction another images-related ticket :)

There are too many :) let's create a milestone for a rewrite. And let's agree on an image manipulation library

Consolidating on #6152