improve error checks

Mser sample improvments (#12032)

* Fixed bug in detect_mser sample
Wrong number of colors used to generate the synthetic images

* Formatting improvements

* Using safer casts

* Improved readability of legend generation

* Various readability fixes in detect_mser sample

the static variables will cause race-condition when operating in
multithread scenarios.
Signed-off-by: Teng Yiliang <ylteng@outlook.com>
Signed-off-by: Teng Yiliang <yiliang.teng@weimob.com>

  * replace binary literal prefix to hexadecimal literal prefix

Example (reuse 'Transform' test case):
PERF_TEST(Transform, getPerspectiveTransform_1000) { ... }
PERF_TEST(Transform, getPerspectiveTransform_QR_1000) { ... }

* Add Java overloads for each default argument

* Add "fisheye_" prefix for cv::fisheye:: functions and enums

Signed-off-by: Li Peng <peng.li@intel.com>

* core:OE-27 prepare universal intrinsics to expand (#11022)

* core:OE-27 prepare universal intrinsics to expand (#11022)

* core: Add universal intrinsics for AVX2

* updated implementation of wide univ. intrinsics; converted several OpenCV HAL functions: sqrt, invsqrt, magnitude, phase, exp to the wide universal intrinsics.

* converted log to universal intrinsics; cleaned up the code a bit; added v_lut_deinterleave intrinsics.

* core: Add universal intrinsics for AVX2

* fixed multiple compile errors

* fixed many more compile errors and hopefully some test failures

* fixed some more compile errors

* temporarily disabled IPP to debug exp & log; hopefully fixed Doxygen complains

* fixed some more compile errors

* fixed v_store(short*, v_float16&) signatures

* trying to fix the test failures on Linux

* fixed some issues found by alalek

* restored IPP optimization after the patch with AVX wide intrinsics has been properly tested

* restored IPP optimization after the patch with AVX wide intrinsics has been properly tested