Similar Image Search Borked?

Hey everyone.

I've been running around Pixiv, finding a few nice pics and using the Danbooru Image search to confirm if a duplicate already exists in the site. Problem is, the last two searches I did via the Image search returned "No such image in Danbooru", but when I try uploading, I finally get told that a duplicate exists and it tells me where the real deal was.

The two I tried on image search

http://www.pixiv.net/member_illust.php?mode=medium&illust_id=8237684
http://www.pixiv.net/member_illust.php?mode=medium&illust_id=8070718

The subsequent uploads

http://danbooru.donmai.us/uploads/68079
http://danbooru.donmai.us/uploads/68082

Transparent backgrounds fuck up iqdb, that's all it is.

It's mainly because iqdb uses a white background for transparency like Pixiv does, whereas Danbooru uses a black background. Since Danbooru also hardcodes the background into the thumbnail (because it's saved as .jpg), there's no way to compare the transparency properly.

The solution would be for Danbooru to either switch to a white background (which I think looks better anyway for the vast majority of pics), or save transparent PNG thumbnails in that case.

Danbooru switched to a white background for transparency already. The problem is that existing images from before D2 haven't been fixed.