detect the position of an object

i work on registration job , that include alignment of two images , the first is a part of another or it represent one object into the second image which have multiple objects. if you can help me to find the position of the first inside the second using any feature discrbtor.

[Walter Roberson]

Duplicates http://uk.mathworks.com/matlabcentral/answers/254767-how-i-can-find-the-position-of-an-object-on-an-image-using-feature-extractor