Use checkVector over "2-point trick"

Fix warnings on MSVC compiler

- reduce unused dependencies

* Computer Vision based Alpha Matting Code

alpha matting code

This is a combination of 3 commits.

removed whitespaces

addressed issues raised in the PR

removed whitespaces

* removed global variable

* incorporated changes suggested by second round of review

* updated build instructions

* changed to OutputArray

* removed whitespaces

* alphamat: fix bugs triggered by assertions of Debug builds

* alphamat: fix documentation

* alphamat: coding style fixes

- get rid of std::cout
- remove clock_t
- drop unnecessary cast: float pix = tmap.at<uchar>(i, j);
- global 'dim' => 'ALPHAMAT_DIM'
- fix sample command line handling

* alphamat: apply clang-format

* clang-format fixups

* Fix for Depth Registration. Issue #2234

* Fix style

* Incorporating suggestions. 1. Trailing whitespace 2. Matx33f 3. EXPECT_EQ

* test: use Matx33f ctor

* Adding constructor for kinfu_Params(). Allows users to configure parameters for KinFu Algorithm

* Trailing whitespace correct

* Add constructor for TSDF Initial Pose. Allowed parameters are Matx33f,Vec3f and Matx44f. Also added function setInitialVolumePose to handle Matx44f param data type.

SinusoidalPattern::unwrapPhaseMap now takes an InputArray instead of InputArrayOfArrays to correct a Python binding problem
present a scriptable HistogramPhaseUnwrapping::create

replicate C++ structured_light test in Python

PhaseUnwrapping now init unwrappedPhase so pixel outside the mask area are set to 0

python binding for HistogramPhaseUnwrapping::Params to use HistogramPhaseUnwrapping::create

reformatted the documentation

* issue-16736: quick step towards moving SIFT from non-free to free. Moves
include, tests, and implementation to free area.

* FREAK : better rounding off for weighted dx and dy of orientation pairs

* updated using cvRound

* cvRound modified

* Add overload method and fix typos in omnidir (1/2)

Addresses part of https://github.com/opencv/opencv/issues/16601

* Add overload method in omnidir (2/2)

Addresses part of https://github.com/opencv/opencv/issues/16601

videostab: Fix out of range data usage

* videostab: Add simple UTs for video stabilizers

Reproduces issue #5178

* videostab: Fix out of range data usage

Fixes issue #5178

* videostab: Use cv::Range for ranges instead of std::pair