本文主要是介绍opencv 的pyramid down函数verilog实现，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
实现opencv如下的函数，在pyramid lk算法中用到，其他地方也有用得到，单独拿出来。
代码共享在github: https://github.com/tishi43/pyr_down
template<class CastOp, class VecOp> voidpyrDown_( const Mat& _src, Mat& _dst, int borderType ){const int PD_SZ = 5;typedef typename CastOp::type1 WT;typedef typename CastOp::rtype T;CV_Assert( !_src.empty() );Size ssize = _src.size(), dsize = _dst.size();int cn = _src.channels();int bufstep = (int)alignSize(dsize.width*cn, 16);AutoBuffer<WT> _buf(bufstep*PD_SZ + 16);WT* buf = alignPtr((WT*)_buf, 16);int tabL[CV_CN_MAX*(PD_SZ+2)], tabR[CV_CN_MAX*(PD_SZ+2)];AutoBuffer<int> _tabM(dsize.width*cn);int* tabM = _tabM;WT* rows[PD_SZ];CastOp castOp;VecOp vecOp;char path[64] = { 0 };int pyramid_level = 0;sprintf(path, "hor%d.txt", pyramid_level);fopen_s(&f_hor, path, "wb");sprintf(path, "ver%d.txt", pyramid_level);fopen_s(&f_ver, "ver.txt", "wb");CV_Assert( ssize.width > 0 && ssize.height > 0 &&std::abs(dsize.width*2 - ssize.width) <= 2 &&std::abs(dsize.height*2 - ssize.height) <= 2 );int k, x, sy0 = -PD_SZ/2, sy = sy0, width0 = std::min((ssize.width-PD_SZ/2-1)/2 + 1, dsize.width);for( x = 0; x <= PD_SZ+1; x++ ){int sx0 = borderInterpolate(x - PD_SZ/2, ssize.width, borderType)*cn;int sx1 = borderInterpolate(x + width0*2 - PD_SZ/2, ssize.width, borderType)*cn;for( k = 0; k < cn; k++ ){tabL[x*cn + k] = sx0 + k;tabR[x*cn + k] = sx1 + k;}}ssize.width *= cn;dsize.width *= cn;width0 *= cn;for( x = 0; x < dsize.width; x++ )tabM[x] = (x/cn)*2*cn + x % cn;for( int y = 0; y < dsize.height; y++ ){T* dst = _dst.ptr<T>(y);WT *row0, *row1, *row2, *row3, *row4;// fill the ring buffer (horizontal convolution and decimation)for( ; sy <= y*2 + 2; sy++ ){WT* row = buf + ((sy - sy0) % PD_SZ)*bufstep;int _sy = borderInterpolate(sy, ssize.height, borderType);const T* src = _src.ptr<T>(_sy);int limit = cn;const int* tab = tabL;for( x = 0;;){for( ; x < limit; x++ ){row[x] = src[tab[x+cn*2]]*6 + (src[tab[x+cn]] + src[tab[x+cn*3]])*4 +src[tab[x]] + src[tab[x+cn*4]];if (sy >= 0)Log_hor("y=%d x=%d conv=%d\n",sy,x,row[x]);}if( x == dsize.width )break;if( cn == 1 ){for (; x < width0; x++){row[x] = src[x * 2] * 6 + (src[x * 2 - 1] + src[x * 2 + 1]) * 4 +src[x * 2 - 2] + src[x * 2 + 2];if (sy >= 0)Log_hor("y=%d x=%d conv=%d\n",sy, x, row[x]);}}else if( cn == 3 ){for( ; x < width0; x += 3 ){const T* s = src + x*2;WT t0 = s[0]*6 + (s[-3] + s[3])*4 + s[-6] + s[6];WT t1 = s[1]*6 + (s[-2] + s[4])*4 + s[-5] + s[7];WT t2 = s[2]*6 + (s[-1] + s[5])*4 + s[-4] + s[8];row[x] = t0; row[x+1] = t1; row[x+2] = t2;}}else if( cn == 4 ){for( ; x < width0; x += 4 ){const T* s = src + x*2;WT t0 = s[0]*6 + (s[-4] + s[4])*4 + s[-8] + s[8];WT t1 = s[1]*6 + (s[-3] + s[5])*4 + s[-7] + s[9];row[x] = t0; row[x+1] = t1;t0 = s[2]*6 + (s[-2] + s[6])*4 + s[-6] + s[10];t1 = s[3]*6 + (s[-1] + s[7])*4 + s[-5] + s[11];row[x+2] = t0; row[x+3] = t1;}}else{for( ; x < width0; x++ ){int sx = tabM[x];row[x] = src[sx]*6 + (src[sx - cn] + src[sx + cn])*4 +src[sx - cn*2] + src[sx + cn*2];}}limit = dsize.width;tab = tabR - x;}}// do vertical convolution and decimation and write the result to the destination imagefor( k = 0; k < PD_SZ; k++ )rows[k] = buf + ((y*2 - PD_SZ/2 + k - sy0) % PD_SZ)*bufstep;row0 = rows[0]; row1 = rows[1]; row2 = rows[2]; row3 = rows[3]; row4 = rows[4];//x = vecOp(rows, dst, (int)_dst.step, dsize.width);x = 0;for (; x < dsize.width; x++){dst[x] = castOp(row2[x] * 6 + (row1[x] + row3[x]) * 4 + row0[x] + row4[x]);Log_ver("y=%d x=%d conv=%d cast=%d(0x%x)\n", y, x, row2[x] * 6 + (row1[x] + row3[x]) * 4 + row0[x] + row4[x]+128, dst[x], dst[x]);}}fclose(f_hor);fclose(f_ver);}这篇关于opencv 的pyramid down函数verilog实现的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
