Oftentimes when we are surfing the net, we come across photos or images that are not attributed to any source. Google solves this problem for us with Google Image Search “Search by Image” feature.

Recently I have started a Tumblr application that finds photos of particular models on the Tumblr network.  One problem I had was that oftentimes you couldn’t find what the source of the image was, where it came from, or what the model’s name was as there was no tags, watermarks, or any information besides the photo.

I wanted to give my users a way to find out the source of the photo with a “Find similar images” button.

Google’s “Search by Image” feature immediately came to mind, but the solution wasn’t apparent.  At first glance, there was no API, and the javascript on their “Search by Image” feature was obfuscated.

However, by disabling javascript, you quickly find out that Google is very complete in their service to all users.

You may use  http://images.google.com/searchbyimage with a image_url GET variable to find similar images to a given URL.  This makes it easy to programmatically create a “Find similiar images” button.

Here’s an example:

http://images.google.com/searchbyimage?image_url=http://beautybuz.com/files/2011/04/makeup_artist_model_fiona.jpg