给个例程
时间: 2023-08-05 17:05:28 浏览: 44
以下是一个使用SSE2指令集加速WARP_INVERSE_MAP算法的示例代码:
```c++
#include <emmintrin.h>
void warpAffineInverseMapSSE2(const Mat& src, Mat& dst, const Mat& M)
{
int src_rows = src.rows, src_cols = src.cols;
int dst_rows = dst.rows, dst_cols = dst.cols;
__m128i zero = _mm_setzero_si128();
for (int i = 0; i < dst_rows; i++)
{
uchar* dst_data = dst.ptr<uchar>(i);
for (int j = 0; j < dst_cols; j += 8)
{
__m128i dst_idx = _mm_set_epi32(j + 7, j + 6, j + 5, j + 4);
__m128i dst_idx2 = _mm_set_epi32(j + 3, j + 2, j + 1, j);
__m128i x = _mm_add_epi32(_mm_mul_epu32(dst_idx, M.row(0)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(1)));
__m128i y = _mm_add_epi32(_mm_mul_epu32(dst_idx, M.row(3)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(4)));
__m128i w = _mm_add_epi32(_mm_mul_epu32(dst_idx, M.row(6)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(7)));
__m128i x2 = _mm_add_epi32(_mm_mul_epu32(dst_idx2, M.row(0)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(1)));
__m128i y2 = _mm_add_epi32(_mm_mul_epu32(dst_idx2, M.row(3)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(4)));
__m128i w2 = _mm_add_epi32(_mm_mul_epu32(dst_idx2, M.row(6)), _mm_mul_epu32(_mm_set1_epi32(i), M.row(7)));
__m128i x_inv = _mm_srli_epi32(_mm_div_epi32(_mm_add_epi32(x, w), w), 16);
__m128i y_inv = _mm_srli_epi32(_mm_div_epi32(_mm_add_epi32(y, w), w), 16);
__m128i mask_x = _mm_and_si128(_mm_cmpgt_epi32(x_inv, zero), _mm_cmplt_epi32(x_inv, _mm_set1_epi32(src_cols)));
__m128i mask_y = _mm_and_si128(_mm_cmpgt_epi32(y_inv, zero), _mm_cmplt_epi32(y_inv, _mm_set1_epi32(src_rows)));
__m128i mask_xy = _mm_and_si128(mask_x, mask_y);
__m128i src_idx = _mm_add_epi32(_mm_mul_epu32(y_inv, _mm_set1_epi32(src_cols)), x_inv);
__m128i src_data = _mm_and_si128(_mm_loadu_si128((__m128i*)(src.data + src_idx)), mask_xy);
__m128i dst_data1 = _mm_and_si128(_mm_loadl_epi64((__m128i*)(dst_data + j)), _mm_xor_si128(mask_xy, _mm_set1_epi8(0xFF)));
__m128i dst_data2 = _mm_and_si128(_mm_loadl_epi64((__m128i*)(dst_data + j + 4)), _mm_xor_si128(mask_xy, _mm_set1_epi8(0xFF)));
__m128i res = _mm_or_si128(_mm_or_si128(dst_data1, _mm_slli_si128(src_data, j & 7)), _mm_slli_si128(dst_data2, (j + 4) & 7));
_mm_storeu_si128((__m128i*)(dst_data + j), res);
}
}
}
```
该代码中,使用了SSE2指令集对仿射变换的计算进行加速,并使用了SIMD指令对图像像素的读取和写入进行优化,以提高图像处理效率。