Question

I am trying to centre an image in a frame as shown below. I am using openCV and C. I searched for linear transformations and shifting functions in openCV but got nothing so far. Would anyone be able to advise me as to which functions to use in order to achieve the effect in the 2nd image? I would greatly appreciate it.

Answer 1

Have you looked at transform?

http://opencv.willowgarage.com/documentation/python/operations_on_arrays.html#transform

Transform(src, dst, transmat, shiftvec=NULL) → None¶

Performs matrix transformation of every array element.
Parameters: 

    src (CvArr) – The first source array
    dst (CvArr) – The destination array
    transmat (CvMat) – Transformation matrix
    shiftvec (CvMat) – Optional shift vector