How can I perform image registration on very simple black and white images with repeating patterns?

What I need to do is pick out a known shape from a jumble of other shapes, and return its translation, rotation and scale.

Here's an example - given this photo: http://s17.postimage.org/5thesoem7/paint2.png

I need to return the x, y offset, rotation and scale of this shape: http://s14.postimage.org/hnl0vsz8h/template2.png

I'm testing the shapes in the big image one at a time (using bwconncomp) and I followed the Image Registration example I found here: http://www.mathworks.co.uk/help/toolbox/vision/gs/btd0kxr.html#btd1247

The problem is that's not working at all, its pretty much matching points randomly. I get the impression that the SURF features thing really wants a big multicoloured image, and my little black and white squares are too simple or repetitive for it to work.

My main problem is inexperience: I've been doing this for just over a day and I wouldn't even know what to google.

Can anyone suggest a better approach?

Answer 1

[Image Analyst]

Have you tried normxcorr2() yet?