Serializing OpenCV Mat_

The earlier answers are good, but they won’t work for non-continuous matrices which arise when you want to serialize regions of interest (among other things). Also, it is unnecessary to serialize elemSize() because this is derived from the type value. Here’s some code that will work regardless of continuity (with includes/namespace) #pragma once #include <boost/archive/text_oarchive.hpp> … Read more

What is the algorithm that opencv uses for finding contours?

If you read the documentation it is mentioned this function implements the algorithm of: Suzuki, S. and Abe, K., Topological Structural Analysis of Digitized Binary Images by Border Following. CVGIP 30 1, pp 32-46 (1985) OpenCV is open source if you want to see how this is implemented just need to read the code: … Read more

Using hierarchy in findContours () in OpenCV?

The hierarchy returned by findContours has the following form: hierarchy[idx][{0,1,2,3}]={next contour (same level), previous contour (same level), child contour, parent contour} CV_RETR_CCOMP, returns a hierarchy of outer contours and holes. This means elements 2 and 3 of hierarchy[idx] have at most one of these not equal to -1: that is, each element has either no … Read more

Video Stabilization with OpenCV

I can suggest one of the following solutions: Using local high level features: OpenCV includes SURF, so: for each frame, extract SURF features. Then build feature Kd-Tree (also in OpenCV), then match each two consecutive frames to find pairs of corresponding features. Feed those pairs into cvFindHomography to compute the homography between those frames. Warp … Read more

OpenCV / SURF How to generate a image hash / fingerprint / signature out of the descriptors?

The feature data you mention (position, laplacian, size, orientation, hessian) is insufficient for your purpose (these are actually the less relevant parts of the descriptor if you want to do matching). The data you want to look at are the “descriptors” (the 4th argument): void cvExtractSURF(const CvArr* image, const CvArr* mask, CvSeq** keypoints, CvSeq** descriptors, … Read more