SSE速度优化：彩色图转灰度图 （OpenCV、SSE、AVX、OpenMP、std::async线程对比）

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// TestOpenCV4.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//
#include "pch.h"
#include 
#include "vInclude.h"
#include 
#include 
#include 
#include "omp.h" 

using namespace std;
using namespace cv;

void RGB2Y_0(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride)
{
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT;
	for (int Y = 0; Y < Height; Y++)
	{
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		for (int X = 0; X < Width; X++, LinePS += 3)
		{
			LinePD[X] = (B_WT * LinePS[0] + G_WT * LinePS[1] + R_WT * LinePS[2]) >> 8;
		}
	}
}

void RGB2Y_1(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride) {
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT;
	for (int Y = 0; Y < Height; Y++) {
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		#pragma omp parallel for
		for (int X = 0; X < Width; X++) 
		{
			unsigned char * Line = LinePS + 3 * X;
			LinePD[X] = (B_WT * Line[0] + G_WT * Line[1] + R_WT * Line[2]) >> 8;
		}
	}
}

void RGB2Y_2(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride) {
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT; // int(0.299 * 256 + 0.5)
	for (int Y = 0; Y < Height; Y++) {
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		int X = 0;
		for (; X < Width - 4; X += 4, LinePS += 12) 
		{
			LinePD[X + 0] = (B_WT * LinePS[0] + G_WT * LinePS[1] + R_WT * LinePS[2]) >> 8;
			LinePD[X + 1] = (B_WT * LinePS[3] + G_WT * LinePS[4] + R_WT * LinePS[5]) >> 8;
			LinePD[X + 2] = (B_WT * LinePS[6] + G_WT * LinePS[7] + R_WT * LinePS[8]) >> 8;
			LinePD[X + 3] = (B_WT * LinePS[9] + G_WT * LinePS[10] + R_WT * LinePS[11]) >> 8;
		}
	}
}

void RGB2Y_22(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride) {
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT; // int(0.299 * 256 + 0.5)
	for (int Y = 0; Y < Height; Y++) {
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		int X = 0;
		for (; X < Width - 6; X += 6, LinePS += 18)
		{
			LinePD[X + 0] = (B_WT * LinePS[0] + G_WT * LinePS[1] + R_WT * LinePS[2]) >> 8;
			LinePD[X + 1] = (B_WT * LinePS[3] + G_WT * LinePS[4] + R_WT * LinePS[5]) >> 8;
			LinePD[X + 2] = (B_WT * LinePS[6] + G_WT * LinePS[7] + R_WT * LinePS[8]) >> 8;
			LinePD[X + 3] = (B_WT * LinePS[9] + G_WT * LinePS[10] + R_WT * LinePS[11]) >> 8;
			LinePD[X + 4] = (B_WT * LinePS[12] + G_WT * LinePS[13] + R_WT * LinePS[14]) >> 8;
			LinePD[X + 5] = (B_WT * LinePS[15] + G_WT * LinePS[16] + R_WT * LinePS[17]) >> 8;
		}
	}
}

void RGB2Y_3(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride) {
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT; // int(0.299 * 256 + 0.5)

	for (int Y = 0; Y < Height; Y++) {
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		int X = 0;
		for (; X < Width - 12; X += 12, LinePS += 36) 
		{
			__m128i temp0;
			__m128i temp1;
			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 0));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT);
			__m128i p1aL = _mm_mullo_epi16(temp0, temp1);
			p1aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 0))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT)); //1

			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 1));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT);
			__m128i p2aL = _mm_mullo_epi16(temp0, temp1);
			 p2aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 1))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT)); //2

			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 2));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT);
			__m128i p3aL = _mm_mullo_epi16(temp0, temp1);
			p3aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 2))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT)); //3

			__m128i p1aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 8))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));
			__m128i p2aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 9))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p3aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 10))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));

			__m128i p1bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 18))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p2bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 19))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));
			__m128i p3bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 20))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));

			__m128i p1bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 26))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));
			__m128i p2bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 27))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p3bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 28))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));

			__m128i sumaL = _mm_add_epi16(p3aL, _mm_add_epi16(p1aL, p2aL));
			__m128i sumaH = _mm_add_epi16(p3aH, _mm_add_epi16(p1aH, p2aH));
			__m128i sumbL = _mm_add_epi16(p3bL, _mm_add_epi16(p1bL, p2bL));
			__m128i sumbH = _mm_add_epi16(p3bH, _mm_add_epi16(p1bH, p2bH));
			__m128i sclaL = _mm_srli_epi16(sumaL, 8);
			__m128i sclaH = _mm_srli_epi16(sumaH, 8);
			__m128i sclbL = _mm_srli_epi16(sumbL, 8);
			__m128i sclbH = _mm_srli_epi16(sumbH, 8);
			__m128i shftaL = _mm_shuffle_epi8(sclaL, _mm_setr_epi8(0, 6, 12, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftaH = _mm_shuffle_epi8(sclaH, _mm_setr_epi8(-1, -1, -1, 18, 24, 30, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftbL = _mm_shuffle_epi8(sclbL, _mm_setr_epi8(-1, -1, -1, -1, -1, -1, 0, 6, 12, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftbH = _mm_shuffle_epi8(sclbH, _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, 18, 24, 30, -1, -1, -1, -1));
			__m128i accumL = _mm_or_si128(shftaL, shftbL);
			__m128i accumH = _mm_or_si128(shftaH, shftbH);
			__m128i h3 = _mm_or_si128(accumL, accumH);
			//h3 = _mm_blendv_epi8(accumL, accumH, _mm_setr_epi8(0, 0, 0, -1, -1, -1, 0, 0, 0, -1, -1, -1, 1, 1, 1, 1));
			_mm_storeu_si128((__m128i *)(LinePD + X), h3);
		}
	}
}

void RGB2Y_4(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride) {
	const int B_WT = int(0.114 * 256 + 0.5);
	const int G_WT = int(0.587 * 256 + 0.5);
	const int R_WT = 256 - B_WT - G_WT; // int(0.299 * 256 + 0.5)

	for (int Y = 0; Y < Height; Y++) {
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		int X = 0;
		for (; X < Width - 15; X += 15, LinePS += 45)
		{
			__m128i temp0;
			__m128i temp1;
			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 0));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT);
			__m128i p1aL = _mm_mullo_epi16(temp0, temp1);
			p1aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 0))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT)); //1

			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 1));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT);
			__m128i p2aL = _mm_mullo_epi16(temp0, temp1);
			p2aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 1))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT)); //2

			temp0 = _mm_loadu_si128((__m128i *)(LinePS + 2));
			temp0 = _mm_cvtepu8_epi16(temp0);
			temp1 = _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT);
			__m128i p3aL = _mm_mullo_epi16(temp0, temp1);
			p3aL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 2))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT)); //3

			__m128i p1aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 8))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));
			__m128i p2aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 9))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p3aH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 10))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));

			__m128i p1bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 18))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p2bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 19))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));
			__m128i p3bL = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 20))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));

			__m128i p1bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 26))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));
			__m128i p2bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 27))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p3bH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 28))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));

			__m128i p1cH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 36))), _mm_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT));
			__m128i p2cH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 37))), _mm_setr_epi16(G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT));
			__m128i p3cH = _mm_mullo_epi16(_mm_cvtepu8_epi16(_mm_loadu_si128((__m128i *)(LinePS + 38))), _mm_setr_epi16(R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT));

			__m128i sumaL = _mm_add_epi16(p3aL, _mm_add_epi16(p1aL, p2aL));
			__m128i sumaH = _mm_add_epi16(p3aH, _mm_add_epi16(p1aH, p2aH));
			__m128i sumbL = _mm_add_epi16(p3bL, _mm_add_epi16(p1bL, p2bL));
			__m128i sumbH = _mm_add_epi16(p3bH, _mm_add_epi16(p1bH, p2bH));
			__m128i sumcH = _mm_add_epi16(p3cH, _mm_add_epi16(p1cH, p2cH));
			__m128i sclaL = _mm_srli_epi16(sumaL, 8);
			__m128i sclaH = _mm_srli_epi16(sumaH, 8);
			__m128i sclbL = _mm_srli_epi16(sumbL, 8);
			__m128i sclbH = _mm_srli_epi16(sumbH, 8);
			__m128i sclcH = _mm_srli_epi16(sumcH, 8);
			__m128i shftaL = _mm_shuffle_epi8(sclaL, _mm_setr_epi8(0, 6, 12, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftaH = _mm_shuffle_epi8(sclaH, _mm_setr_epi8(-1, -1, -1, 2, 8, 14, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftbL = _mm_shuffle_epi8(sclbL, _mm_setr_epi8(-1, -1, -1, -1, -1, -1, 0, 6, 12, -1, -1, -1, -1, -1, -1, -1));
			__m128i shftbH = _mm_shuffle_epi8(sclbH, _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, 2, 8, 14, -1, -1, -1, -1));
			__m128i shftcH = _mm_shuffle_epi8(sclcH, _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 6, 12, -1));
			__m128i accumL = _mm_or_si128(shftaL, shftbL);
			__m128i accumH = _mm_or_si128(shftaH, shftbH);
			__m128i h3 = _mm_or_si128(accumL, accumH);
			h3 = _mm_or_si128(h3, shftcH);
			_mm_storeu_si128((__m128i *)(LinePD + X), h3);
		}
	}
}

constexpr double B_WEIGHT = 0.114;
constexpr double G_WEIGHT = 0.587;
constexpr double R_WEIGHT = 0.299;
constexpr uint16_t B_WT = static_cast(32768.0 * B_WEIGHT + 0.5);
constexpr uint16_t G_WT = static_cast(32768.0 * G_WEIGHT + 0.5);
constexpr uint16_t R_WT = static_cast(32768.0 * R_WEIGHT + 0.5);
static const __m256i weight_vec = _mm256_setr_epi16(B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT, G_WT, R_WT, B_WT);

void __forceinline _RGB2Y(unsigned char* Src, const int32_t Width, const int32_t start_row, const int32_t thread_stride, const int32_t Stride, unsigned char* Dest)
{
	for (int Y = start_row; Y < start_row+ thread_stride; Y++)
	{
		//Sleep(1);
		unsigned char *LinePS = Src + Y * Stride;
		unsigned char *LinePD = Dest + Y * Width;
		int X = 0;
		for (; X < Width - 10; X += 10, LinePS += 30)
		{
			__m256i temp;
			__m128i tempp = _mm_loadu_si128((const __m128i*)(LinePS + 0));
			temp = _mm256_cvtepu8_epi16(tempp);
			__m256i in1 = _mm256_mulhrs_epi16(temp, weight_vec);
			temp = _mm256_cvtepu8_epi16(_mm_loadu_si128((const __m128i*)(LinePS + 15)));
			__m256i in2 = _mm256_mulhrs_epi16(temp, weight_vec);
			__m256i mul = _mm256_packus_epi16(in1, in2);
			__m256i b1 = _mm256_shuffle_epi8(mul, _mm256_setr_epi8(0, 3, 6, -1, -1, -1, 11, 14, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 4, 7, -1, -1, 9, 12, -1, -1, -1, -1, -1, -1));
			__m256i g1 = _mm256_shuffle_epi8(mul, _mm256_setr_epi8(1, 4, 7, -1, -1, 9, 12, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 2, 5, -1, -1, -1, 10, 13, -1, -1, -1, -1, -1, -1));
			__m256i r1 = _mm256_shuffle_epi8(mul, _mm256_setr_epi8(2, 5, -1, -1, -1, 10, 13, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 3, 6, -1, -1, 8, 11, 14, -1, -1, -1, -1, -1, -1));
			__m256i accum = _mm256_adds_epu8(r1, _mm256_adds_epu8(b1, g1));
			__m128i h3 = _mm_adds_epu8(_mm256_castsi256_si128(accum), _mm256_extracti128_si256(accum, 1));
			_mm_storeu_si128((__m128i *)(LinePD + X), h3);
		}
	}
}


void RGB2Y_5(unsigned char *Src, unsigned char *Dest, int width, int height, int stride)
{
	_RGB2Y(Src, width, 0, height, stride, Dest);
}

void RGB2Y_6(unsigned char *Src, unsigned char *Dest, int width, int height, int stride)
{
	const int32_t hw_concur = std::min(height >> 4, static_cast(std::thread::hardware_concurrency()));
	std::vector> fut(hw_concur);
	const int thread_stride = (height - 1) / hw_concur + 1;
	int i = 0, start = 0;
	for (; i < std::min(height, hw_concur); i++, start += thread_stride)
	{
		fut[i] = std::async(std::launch::async, _RGB2Y, Src, width, start, thread_stride, stride, Dest);
	}
	for (int j = 0; j < i; ++j) 
		fut[j].wait();
}

int main()
{
	Mat src = imread("test.jpg");
	int Height = src.rows;
	int Width = src.cols;
	unsigned char *Src = src.data;
	unsigned char *Dest = new unsigned char[Height * Width];
	int Stride = Width * 3;
	int Radius = 11;

	int64 st; 
	double duration; 

	st = cv::getTickCount();
	Mat newimage_cv;
	cv::cvtColor(src, newimage_cv, COLOR_BGR2GRAY);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("OpenCV:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_1(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("RGB2Y_1:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_2(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("RGB2Y_2:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_3(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("RGB2Y_3:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_4(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("RGB2Y_4:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_5(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 1000;
	printf("RGB2Y_5:%.5f\n", duration);

	st = cv::getTickCount();
	RGB2Y_6(Src, Dest, Width, Height, Stride);
	duration = (cv::getTickCount() - st) / cv::getTickFrequency() * 100;
	printf("RGB2Y_6:%.5f\n", duration);


	Mat dst(Height, Width, CV_8UC1, Dest);
	//imshow("origin", src);
	//imshow("result", dst);
	waitKey(0);
	return 0;
}

 

相关链接：

https://www.cnblogs.com/Imageshop/p/6261719.html

https://github.com/komrad36/RGB2Y