Question

Is there any built in library for sliding a window (custom size) over an image in opencv version 2.x?
I tried to write the algorithm by myself but I found it very painful and probably error-prone.
I need to slide over an image and create histogram for the input of svm.
there is one for HOG Descriptor, which calculates HOG features but I have my own feature set so I just need an algorithm to let me slide over an image.

Answer 1

You can define a Region of Interest (ROI) on a cv::Mat object, which gives you a new Mat object referring to the sub-window. This does not copy the underlying data, merely a new header with the appropriate metadata.

• cv::Mat::operator()

See also this other question:

• OpenCV C++, getting Region Of Interest (ROI) using cv::Mat