How to set ROI in OpenCV?

by

I think you have something wrong. If the first one is smaller than the other one and you want to copy the second image in the first one, you don’t need an ROI. You can just resize the second image in copy it into the first one.

However if you want to copy the first one in the second one, I think this code should work:

cv::Rect roi = cv::Rect((img2.cols - img1.cols)/2,(img2.rows - img1.rows)/2,img1.cols,img1.rows);

cv::Mat roiImg;
roiImg = img2(roi);

img1.copyTo(roiImg);

More Related Contents:

  1. opencv multi channel element access
  2. Easiest way to rotate by 90 degrees an image using OpenCV?
  3. Rotate an image in C++ without using OpenCV functions
  4. Using hierarchy in findContours () in OpenCV?
  5. OpenCV warpperspective
  6. Setup OpenCV-2.3 for Visual Studio 2010
  7. Image Processing: Algorithm Improvement for ‘Coca-Cola Can’ Recognition
  8. Getting started with OpenCV 2.4 and MinGW on Windows 7
  9. What does OpenCV’s cvWaitKey( ) function do?
  10. OpenCV better detection of red color?
  11. OpenCV C++/Obj-C: Advanced square detection
  12. how to check whether two matrices are identical in OpenCV
  13. Nonfree module is missing in OpenCV 3.0
  14. openCV program compile error “libopencv_core.so.2.4: cannot open shared object file: No such file or directory” in ubuntu 12.04
  15. Copy an cv::Mat inside a ROI of another one
  16. Compiling a static executable with CMake
  17. read pixel value in bmp file [closed]
  18. Converting cv::Mat to IplImage*
  19. Fast color quantization in OpenCV
  20. Convert a single color with cvtColor
  21. How to get a color palette from an image using OpenCV [closed]
  22. Inverse fourier transformation in OpenCV
  23. scale and rotation Template matching
  24. cmake find_package specify path
  25. Writing robust (color and size invariant) circle detection with OpenCV (based on Hough transform or other features)
  26. load image with openCV Mat c++
  27. OpenCV: Find all non-zero coordinates of a binary Mat image
  28. How to detect region of large # of white pixels using OpenCV?
  29. SVM classifier based on HOG features for “object detection” in OpenCV
  30. Using OpenCV Output as Webcam [closed]

Leave a Comment