Find position of an object in an other image

I want to detect the position of a simple object of an image into another image. The object is like a simple rectangle of couple of overlapping rectangles with uniform color background.

I tried matlab functions of detectHarrisFeatures and detectSURFFeatures.

detectHarrisFeatures works well but fails when the pair of images have a different magnifications (change in number of pixels of the object). It also fails when there is a small disturbance (defect, hot spot, partical) in one of the image. Whereas detectSURFFeatures fails when the object is too simple (eg. just a rectangle)

Any suggestion? Thanks in advance

Answer 1

[Image Analyst]

You might try Hu's moments which are rotation and scale invariant.

http://www.youtube.com/watch?v=Nc06tlZAv_Q