Magento - Removing the black background from automatic thumbnails? - php

Question

On a Magento site, I’m just uploading one picture per product, and using that as the base, small and thumbnail images. However, my pictures aren’t square, so I’m getting a black background added to the thumbnail that’s created. Any ideas how to change that to a white background?
http://www.magentocommerce.com/?ACT=25&fid=10&aid=10785_osKeOnfKFLFvgqVYbr0j&board_id=1
I’ve searched for this but can’t find a decent answer anywhere…

Answer 1

I found a workaround for this. The side effect is that the class used for image resize will fill all images with white (even transparent ones), but this doesn't realy affect Magento since it doesn't use transparent fill anyway. So to solve the issue do this:
Go to lib\Varien\Image\Adapter\Gd2.php in your magento folder
Find this line
$this->_fillBackgroundColor($newImage);
and replace it with this line
$this->_fillBackgroundColor($newImage,$frameWidth,$frameWidth);
Find this line
private function _fillBackgroundColor(&$imageResourceTo)
and replace it with this
private function _fillBackgroundColor(&$imageResourceTo,$w,$h)
Find this code
if (!imagefill($imageResourceTo, 0, 0, $color)) {
throw new Exception("Failed to fill image background with color {$r} {$g} {$b}.");
}
and replace it with this
imagefilledrectangle($imageResourceTo,0,0,$w,$h,$color);
That is it. The problem comes from the PHP function imagefill in Gd2 not working on some setings. This is a workaround using imagefilledrectangle, and worked for me. Hope it solves your problem too.

Answer 2

Correction on point 4 from Adi's answer:
4. Find this code
if (!imagefill($imageResourceTo, 0, 0, $color)) { throw new Exception("Failed to fill image background with color {$r} {$g} {$b}."); }
and replace it with:
if (!imagefilledrectangle($imageResourceTo,0,0,$w,$h,$color)) {
throw new Exception("Failed to fill image background with color {$r} {$g} {$b}.");

Answer 3

Varien_Image which is used in Magento offers a possibility to set background color of scaled image. You can use similar code somewhere before outputting the image (resize method?) to make background white:
$image->backgroundColor(array(255, 255, 255));

Answer 4

Adi's answer led me in the right direction, but I was still getting a black line on my images. I discovered that when an image is cropped, Magento creates a canvas background, then the image on top of it. The canvas was producing the black line on my images.
I managed to fix it by adding Adi's changes, and then additionally, in the crop() function (in the same file), I added:
list($r, $g, $b) = $this->_backgroundColor;
$bg_color = imagecolorallocate($canvas, $r, $g, $b);
imagefill($canvas, 0, 0, $bg_color);
After the function (around line 554, after adi's changes):
imagecopyresampled
Now my images have the background colour they should have!
Another thing to note, instead of editing this file directly in the core, it should be copied to:
app/code/local/Varien/Image/Adapter/Gd2.php
Hope this helps someone struggling with the same issue.