add input paramter checking that verifies the existance of the input files to stero_match example
Merge remote-tracking branch 'upstream/master'
check input paramter by checking the image size
update IPPICV package
IPPICV: disable NormDiff_L1_16s_C1R for IPP/ICV 8.2/8.2.1
IPPICV: disable boxFilter 16SC1/16UC1 (performance)
remove the unnecessary header file
Minor optimization for ocl_canny
Removed incorrect using of rootn() and powr() in ocl_pow
fixed test for ocl WarpAffine
Merge pull request #3396 from akarsakov:ocl_pow_fix
Merge pull request #3138 from alalek:icv_update
Correctly unrolled some cycles
Fix HoughLines crashes (Bug #3959).

Avoid phi exceed PI/2 to get the negative value of cos(phi).
fixed my_umat(roi).clone() test by disabling poorly aligned ROI's. Real fix of the problem will require a separate branch in UMat::copyTo().
Merge pull request #3397 from ElenaGvozdeva:ocl_WarpAffine_test
Merge pull request #3392 from wangyan42164:houghlines_bug_fix
Merge pull request #3357 from briansp2020:master
Merge pull request #3394 from akarsakov:ocl_canny
Merge pull request #3400 from vpisarev:fixed_umat_test_crash