diff --git a/modules/calib3d/src/calibinit.cpp b/modules/calib3d/src/calibinit.cpp index 283a9217a9..123cf2ba04 100644 --- a/modules/calib3d/src/calibinit.cpp +++ b/modules/calib3d/src/calibinit.cpp @@ -497,7 +497,8 @@ int cvFindChessboardCorners( const void* arr, CvSize pattern_size, int max_quad_buf_size = 0; cvFree(&quads); cvFree(&corners); - int quad_count = icvGenerateQuads( &quads, &corners, storage, thresh_img_new, flags, &max_quad_buf_size ); + Mat binarized_img = thresh_img_new.clone(); // make clone because cvFindContours modifies the source image + int quad_count = icvGenerateQuads( &quads, &corners, storage, binarized_img, flags, &max_quad_buf_size ); PRINTF("Quad count: %d/%d\n", quad_count, (pattern_size.width/2+1)*(pattern_size.height/2+1)); SHOW_QUADS("New quads", thresh_img_new, quads, quad_count); if (processQuads(quads, quad_count, pattern_size, max_quad_buf_size, storage, corners, out_corners, out_corner_count, prev_sqr_size)) @@ -562,7 +563,8 @@ int cvFindChessboardCorners( const void* arr, CvSize pattern_size, int max_quad_buf_size = 0; cvFree(&quads); cvFree(&corners); - int quad_count = icvGenerateQuads( &quads, &corners, storage, thresh_img, flags, &max_quad_buf_size); + Mat binarized_img = (useAdaptive) ? thresh_img : thresh_img.clone(); // make clone because cvFindContours modifies the source image + int quad_count = icvGenerateQuads( &quads, &corners, storage, binarized_img, flags, &max_quad_buf_size); PRINTF("Quad count: %d/%d\n", quad_count, (pattern_size.width/2+1)*(pattern_size.height/2+1)); SHOW_QUADS("Old quads", thresh_img, quads, quad_count); if (processQuads(quads, quad_count, pattern_size, max_quad_buf_size, storage, corners, out_corners, out_corner_count, prev_sqr_size))