Note:
This is a duplicate of my SO question.
Observation
Performing the same Laplacian operation in C++ and Python appears to produce different results. Notably, the C++ variant does not report negative slopes in the result matrix.
Versions
- OpenCV => C++ 3.4.1 and 4.4, Python 4.1.1
- Operating System / Platform => Ubuntu 18.04
- Compiler => g++
Similar issues:
- There are several SO questions with similar reports, but they all appear to have some unrelated error. I list a few in my SO question.
- An issue was reported on Github reports a similar platform problem, but it was fixed by not attempting to use the Laplacian function in place. I use
clone()in my code to avoid this issue. - A question on this site appears almost identical, sadly it has no satisfactory answer.
Source code and files for duplication
Gist link to C++ and Python code
Quick description of the code
My code is a pared down segment of a larger program where I want to extract the first derivative of pixel brightness on the points of a detected contour for discriminant analysis. I use two images for this in my sample program above to reduce the amount of code for a MWE.
Question:
Is there some simple issue I am not seeing in my code like the other similar (yet unrelated) questions I mention? I would like to make sure I have covered every possible solution before raising an Issue on Github.