要C++的
时间: 2023-07-11 17:19:11 浏览: 42
好的,这是一个使用C++实现的带参数WARP_INVERSE_MAP的warpAffine函数,并使用SSE2指令集加速的示例代码:
```c++
#include <iostream>
#include <opencv2/opencv.hpp>
#include <emmintrin.h>
using namespace std;
using namespace cv;
void warpAffine_sse2(const Mat& src, Mat& dst, const Mat& M)
{
int h = src.rows;
int w = src.cols;
dst.create(h, w, src.type());
// 计算变换矩阵的逆矩阵
Mat M_inv;
invertAffineTransform(M, M_inv);
// 使用SSE2指令集进行加速
__m128i zero = _mm_setzero_si128();
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x += 4)
{
float fx[4], fy[4];
__m128i ix, iy;
__m128i i0, i1, i2, i3;
__m128i val0, val1, val2, val3;
__m128 dx, dy;
__m128i irow0, irow1;
__m128 frow0, frow1;
// 计算变换后的像素坐标
for (int k = 0; k < 4; k++)
{
int x0 = x + k;
int y0 = y;
fx[k] = M_inv.at<float>(0, 0) * x0 + M_inv.at<float>(0, 1) * y0 + M_inv.at<float>(0, 2);
fy[k] = M_inv.at<float>(1, 0) * x0 + M_inv.at<float>(1, 1) * y0 + M_inv.at<float>(1, 2);
}
// 判断像素坐标是否在图像范围内
ix = _mm_cvtps_epi32(_mm_load_ps(fx));
iy = _mm_cvtps_epi32(_mm_load_ps(fy));
i0 = _mm_cmplt_epi32(ix, zero);
i1 = _mm_cmplt_epi32(iy, zero);
i2 = _mm_cmpgt_epi32(ix, _mm_set1_epi32(w - 2));
i3 = _mm_cmpgt_epi32(iy, _mm_set1_epi32(h - 2));
if (_mm_movemask_epi8(_mm_or_si128(_mm_or_si128(i0, i1), _mm_or_si128(i2, i3))) != 0)
continue;
// 双线性插值
dx = _mm_sub_ps(_mm_load_ps(fx), _mm_cvtepi32_ps(ix));
dy = _mm_sub_ps(_mm_load_ps(fy), _mm_cvtepi32_ps(iy));
irow0 = _mm_mul_epu32(_mm_add_epi32(_mm_mul_epu32(_mm_sub_epi32(_mm_set1_epi32(1), _mm_castps_si128(dy)), ix), _mm_mul_epu32(_mm_castps_si128(dy), _mm_add_epi32(ix, _mm_set1_epi32(1)))), _mm_set1_epi32(w * src.elemSize()));
irow1 = _mm_add_epi32(irow0, _mm_set1_epi32(w * src.elemSize()));
frow0 = _mm_sub_ps(_mm_set1_ps(1), dx);
frow1 = dx;
val0 = _mm_unpacklo_epi8(_mm_loadl_epi64((const __m128i*)(src.data + iy[0] * src.step + irow0[0])), zero);
val1 = _mm_unpackhi_epi8(_mm_loadl_epi64((const __m128i*)(src.data + iy[0] * src.step + irow0[0])), zero);
val2 = _mm_unpacklo_epi8(_mm_loadl_epi64((const __m128i*)(src.data + iy[0] * src.step + irow1[0])), zero);
val3 = _mm_unpackhi_epi8(_mm_loadl_epi64((const __m128i*)(src.data + iy[0] * src.step + irow1[0])), zero);
val0 = _mm_mullo_epi16(val0, _mm_castps_si128(frow0));
val1 = _mm_mullo_epi16(val1, _mm_castps_si128(frow0));
val2 = _mm_mullo_epi16(val2, _mm_castps_si128(frow1));
val3 = _mm_mullo_epi16(val3, _mm_castps_si128(frow1));
val0 = _mm_add_epi16(val0, val2);
val1 = _mm_add_epi16(val1, val3);
val0 = _mm_srli_epi16(_mm_add_epi16(val0, _mm_set1_epi16(1)), 1);
val1 = _mm_srli_epi16(_mm_add_epi16(val1, _mm_set1_epi16(1)), 1);
_mm_storeu_si128((__m128i*)(dst.data + y * dst.step + x * dst.elemSize()), _mm_packus_epi16(val0, val1));
}
}
}
int main()
{
Mat src = imread("test.jpg");
Mat dst1, dst2;
Mat M = (Mat_<float>(2, 3) << 1, 0, 100, 0, 1, 50);
// 使用OpenCV自带的函数进行变换
warpAffine(src, dst1, M, src.size(), WARP_INVERSE_MAP);
// 使用SSE2指令集加速的函数进行变换
warpAffine_sse2(src, dst2, M);
// 比较两个结果是否相同
cout << "diff: " << countNonZero(dst1 != dst2) << endl;
return 0;
}
```
在这个示例代码中,我们首先定义了一个warpAffine_sse2函数,用于进行变换。在函数内部,我们使用了SSE2指令集来加速双线性插值的计算。具体来说,我们使用了_mm_cvtps_epi32将浮点数转换为整数,_mm_cmplt_epi32和_mm_cmpgt_epi32进行了边界判断,_mm_unpacklo_epi8和_mm_unpackhi_epi8进行了像素值的拆分和扩展,_mm_mullo_epi16进行了乘法运算,_mm_add_epi16进行了加法运算,_mm_srli_epi16进行了右移运算,_mm_storeu_si128进行了内存写操作,等等。
最后,我们可以运行这个程序,测试两个函数的性能和正确性。