Lab, Luv and XYZ conversions rewritten to wide intrinsics (#14106)
* rgb2xyz<float> re-vectorized
* rgb2xyz_i vectorized for ushort and uchar
* xyz2rgb<float> vectorized
* xyz2rgb_i vectorized for both uchar and ushort
* intermediate conversions (int->float) rewritten
* packed rgb2luv rewritten
* (some) float conversions rewritten
* burnt volatile int _3 and similar
* RGB2Lab_b rewritten
* tests: logging made better
* RGB2Lab_f (LRGB path) rewritten
* Lab2RGBfloat rewritten
* Lab2RGBinteger and Lab2RGB_b rewritten to wide universal intrinsics
* Luv2RGBinteger wide vectorized
* RGB2Lab_b fixed: v_sub_wrap instead of saturated sub
* warnings fixed
* trying to fix compilation on older compilers
* using 16x8 registers for 8-element dot product
* cleanup added
* splineInterpolate: loop unrolled, perf fix for f32x4
* Lab2RGBfloat: grab 2x more data to process on f32x4
* nrepeats for Luv2RGBfloat, +20% perf
* minor
* nrepeats to RGB2Lab_f
* Lab2RGBinteger: no tab for linear BGR
* nrepeats for RGB2Luvfloat
* Luv2RGBinteger: no tab for linear RGB
* +10% more to perf of Luv2RGBfloat
* nrepeats for 256-simd for Lab2RGBfloat
* less warnings
* BOM removed
* CV_SIMD_WIDTH used for lanes number checking
* trilinearPackedInterpolate: 128-bit specialization added
* fix build; no vx_cleanup(), instrumentation instead
Lab/XYZ modes have been postponed (color_lab.cpp):
- need to split code for tables initialization and for pixels processing first
- no significant performance improvements for switching between SSE42 / AVX2 code generation
Resize reworked using wide universal intrinsics (#13781)
* Added wide universal intrinsics optimized implementation for 3 channel bit-exact linear resize
* Reworked linear resize using new wide LUT intrinsics
* Fix for VSX intrinsics
* LineIterator witout a Mat
cv::LineIterator can be used without being attached to any cv::Mat, it only needs the size and type of data. An alternative constructor has been defined for that.
In that case, a LineIterator can no more be dereferenced with the * operator, but pos() still returns valid pixel positions.
It can be useful when LineIterator is just used to compute positions of pixels on a line, without requiring to build a Mat just for that.
Use case : with a dataset that would represent a huge image, pixel positions can be pre-computed before querying the dataset API.
* Update imgproc.hpp
removed trailing spaces
* Update drawing.cpp
fixed warning
