I have an image which I want to crop, for this I am using masking operation with `copyTo()` function. Here is the code block that does the operation:
// ROI by creating mask for the trapezoid
Mat mask = Mat(frame.rows, frame.cols, CV_8UC1, Scalar(0));
// Create Polygon from vertices
approxPolyDP(pointsForTrapezoid, roiPolygonized, 1.0, true);
// Fill polygon white
fillConvexPoly(mask, &roiPolygonized[0], roiPolygonized.size(), 255, 8, 0);
// Create new image for result storage
Mat maskedImage = Mat(frame.rows, frame.cols, CV_8UC3);
frame.copyTo(maskedImage, mask);
return maskedImage;
However, there is something really weird with this. I get different outputs from each run. Sometimes it works and sometimes it does not. Let me explain with snapshots:
This is the correct mask which I generate:
[![enter image description here][1]][1]
This is the correctly applied mask, after the operation:
[![enter image description here][2]][2]
And these are the ridiculously applied masks, after the operations:
[![enter image description here][3]][3]
[![enter image description here][4]][4]
[![enter image description here][5]][5]
[1]: http://i.stack.imgur.com/3iSfB.png
[2]: http://i.stack.imgur.com/KcBHO.png
[3]: http://i.stack.imgur.com/qHWtc.png
[4]: http://i.stack.imgur.com/UBB7h.png
[5]: http://i.stack.imgur.com/yLjot.png
As you can see, sometimes the masking operation works, and sometimes it does not. I don't know what the hell is wrong with OpenCV, but this shouldn't happen. Same code with same input should not create different output on each run. I suspect that `copyTo()` function is messed up.
Any thoughts?
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