OpenCV代码提取：resize函数的实现

之前在http://blog.csdn.net/fengbingchun/article/details/17335477 中有过对cv::resize函数五种插值算法的介绍。这里将OpenCV3.1中五种插值算法的代码进行了提取调整。支持N通道uchar和float类型。经测试，与OpenCV3.1结果完全一致。

实现代码resize.hpp：

// fbc_cv is free software and uses the same licence as OpenCV// Email: [e-mail]#ifndef FBC_CV_RESIZE_HPP_#define FBC_CV_RESIZE_HPP_/* reference: imgproc/include/opencv2/imgproc.hpp              imgproc/src/imgwarp.cpp*/#include "core/mat.hpp"#include "core/base.hpp"#include "core/saturate.hpp"#include "core/utility.hpp"#include "imgproc.hpp"namespace fbc {static const int MAX_ESIZE = 16;// interpolation formulas and tablesconst int INTER_RESIZE_COEF_BITS = 11;const int INTER_RESIZE_COEF_SCALE = 1 << INTER_RESIZE_COEF_BITS;template<typename _Tp, int chs> static int resize_nearest(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst);template<typename _Tp, int chs> static int resize_linear(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst);template<typename _Tp, int chs> static int resize_cubic(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst);template<typename _Tp, int chs> static int resize_area(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst);template<typename _Tp, int chs> static int resize_lanczos4(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst);// resize the image src down to or up to the specified size// support type: uchar/floattemplate<typename _Tp, int chs>int resize(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst, int interpolation = NTER_LINEAR){FBC_Assert((interpolation >= 0) && (interpolation < 5));FBC_Assert((src.rows >= 4 && src.cols >= 4) && (dst.rows >= 4  && dst.cols >= 4));FBC_Assert((sizeof(_Tp) == 1) || sizeof(_Tp) == 4); // uchar || floatSize ssize = src.size();Size dsize = dst.size();if (dsize == ssize) {// Source and destination are of same size. Use simple copy.src.copyTo(dst);return 0;}switch (interpolation) {case 0: {resize_nearest(src, dst);break;}case 1: {resize_linear(src, dst);break;}case 2: {resize_cubic(src, dst);break;}case 3: {resize_area(src, dst);break;}case 4: {resize_lanczos4(src, dst);break;}default:return -1;}return 0;}struct DecimateAlpha{int si, di;float alpha;};template<typename type>static int computeResizeAreaTab(int ssize, int dsize, int cn, double scale, DecimateAlpha* tab){int k = 0;for (int dx = 0; dx < dsize; dx++) {double fsx1 = dx * scale;double fsx2 = fsx1 + scale;double cellWidth = std::min(scale, ssize - fsx1);int sx1 = fbcCeil(fsx1), sx2 = fbcFloor(fsx2);sx2 = std::min(sx2, ssize - 1);sx1 = std::min(sx1, sx2);if (sx1 - fsx1 > 1e-3) {assert(k < ssize * 2);tab[k].di = dx * cn;tab[k].si = (sx1 - 1) * cn;tab[k++].alpha = (float)((sx1 - fsx1) / cellWidth);}for (int sx = sx1; sx < sx2; sx++) {assert(k < ssize * 2);tab[k].di = dx * cn;tab[k].si = sx * cn;tab[k++].alpha = float(1.0 / cellWidth);}if (fsx2 - sx2 > 1e-3) {assert(k < ssize * 2);tab[k].di = dx * cn;tab[k].si = sx2 * cn;tab[k++].alpha = (float)(std::min(std::min(fsx2 - sx2, 1.), cellWidth) / cellWidth);}}return k;}template<typename ST, typename DT> struct Cast{typedef ST type1;typedef DT rtype;DT operator()(ST val) const { return saturate_cast<DT>(val); }};template<typename ST, typename DT, int bits> struct FixedPtCast{typedef ST type1;typedef DT rtype;enum { SHIFT = bits, DELTA = 1 << (bits - 1) };DT operator()(ST val) const { return saturate_cast<DT>((val + DELTA) >> SHIFT); }};template<typename type>static type clip(type x, type a, type b){return x >= a ? (x < b ? x : b - 1) : a;}template<typename T, typename WT, typename AT>struct HResizeLinear{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const T** src, WT** dst, int count,const int* xofs, const AT* alpha,int swidth, int dwidth, int cn, int xmin, int xmax, int ONE) const{int dx, k;int dx0 = 0;for (k = 0; k <= count - 2; k++) {const T *S0 = src[k], *S1 = src[k + 1];WT *D0 = dst[k], *D1 = dst[k + 1];for (dx = dx0; dx < xmax; dx++) {int sx = xofs[dx];WT a0 = alpha[dx * 2], a1 = alpha[dx * 2 + 1];WT t0 = S0[sx] * a0 + S0[sx + cn] * a1;WT t1 = S1[sx] * a0 + S1[sx + cn] * a1;D0[dx] = t0; D1[dx] = t1;}for (; dx < dwidth; dx++) {int sx = xofs[dx];D0[dx] = WT(S0[sx] * ONE); D1[dx] = WT(S1[sx] * ONE);}}for (; k < count; k++) {const T *S = src[k];WT *D = dst[k];for (dx = 0; dx < xmax; dx++) {int sx = xofs[dx];D[dx] = S[sx] * alpha[dx * 2] + S[sx + cn] * alpha[dx * 2 + 1];}for (; dx < dwidth; dx++) {D[dx] = WT(S[xofs[dx]] * ONE);}}}};template<typename T, typename WT, typename AT, class CastOp>struct VResizeLinear{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const WT** src, T* dst, const AT* beta, int width) const{WT b0 = beta[0], b1 = beta[1];const WT *S0 = src[0], *S1 = src[1];CastOp castOp;int x = 0;for (; x <= width - 4; x += 4) {WT t0, t1;t0 = S0[x] * b0 + S1[x] * b1;t1 = S0[x + 1] * b0 + S1[x + 1] * b1;dst[x] = castOp(t0); dst[x + 1] = castOp(t1);t0 = S0[x + 2] * b0 + S1[x + 2] * b1;t1 = S0[x + 3] * b0 + S1[x + 3] * b1;dst[x + 2] = castOp(t0); dst[x + 3] = castOp(t1);}for (; x < width; x++) {dst[x] = castOp(S0[x] * b0 + S1[x] * b1);}}};template<>struct VResizeLinear<uchar, int, short, FixedPtCast<int, uchar, INTER_RESIZE_COEF_BITS * 2>>{typedef uchar value_type;typedef int buf_type;typedef short alpha_type;void operator()(const buf_type** src, value_type* dst, const alpha_type* beta, int width) const{alpha_type b0 = beta[0], b1 = beta[1];const buf_type *S0 = src[0], *S1 = src[1];int x = 0;for (; x <= width - 4; x += 4) {dst[x + 0] = uchar((((b0 * (S0[x + 0] >> 4)) >> 16) + ((b1 * (S1[x + 0] >> 4)) >> 16) + 2) >> 2);dst[x + 1] = uchar((((b0 * (S0[x + 1] >> 4)) >> 16) + ((b1 * (S1[x + 1] >> 4)) >> 16) + 2) >> 2);dst[x + 2] = uchar((((b0 * (S0[x + 2] >> 4)) >> 16) + ((b1 * (S1[x + 2] >> 4)) >> 16) + 2) >> 2);dst[x + 3] = uchar((((b0 * (S0[x + 3] >> 4)) >> 16) + ((b1 * (S1[x + 3] >> 4)) >> 16) + 2) >> 2);}for (; x < width; x++) {dst[x] = uchar((((b0 * (S0[x] >> 4)) >> 16) + ((b1 * (S1[x] >> 4)) >> 16) + 2) >> 2);}}};template<typename T, typename WT, typename AT>struct HResizeCubic{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const T** src, WT** dst, int count,const int* xofs, const AT* alpha,int swidth, int dwidth, int cn, int xmin, int xmax) const{for (int k = 0; k < count; k++) {const T *S = src[k];WT *D = dst[k];int dx = 0, limit = xmin;for (;;) {for (; dx < limit; dx++, alpha += 4) {int j, sx = xofs[dx] - cn;WT v = 0;for (j = 0; j < 4; j++) {int sxj = sx + j*cn;if ((unsigned)sxj >= (unsigned)swidth) {while (sxj < 0)sxj += cn;while (sxj >= swidth)sxj -= cn;}v += S[sxj] * alpha[j];}D[dx] = v;}if (limit == dwidth)break;for (; dx < xmax; dx++, alpha += 4) {int sx = xofs[dx];D[dx] = S[sx - cn] * alpha[0] + S[sx] * alpha[1] +S[sx + cn] * alpha[2] + S[sx + cn * 2] * alpha[3];}limit = dwidth;}alpha -= dwidth * 4;}}};template<typename T, typename WT, typename AT, class CastOp>struct VResizeCubic{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const WT** src, T* dst, const AT* beta, int width) const{WT b0 = beta[0], b1 = beta[1], b2 = beta[2], b3 = beta[3];const WT *S0 = src[0], *S1 = src[1], *S2 = src[2], *S3 = src[3];CastOp castOp;int x = 0;for (; x < width; x++) {dst[x] = castOp(S0[x] * b0 + S1[x] * b1 + S2[x] * b2 + S3[x] * b3);}}};template<typename T, typename WT, typename AT>struct HResizeLanczos4{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const T** src, WT** dst, int count,const int* xofs, const AT* alpha,int swidth, int dwidth, int cn, int xmin, int xmax) const{for (int k = 0; k < count; k++) {const T *S = src[k];WT *D = dst[k];int dx = 0, limit = xmin;for (;;) {for (; dx < limit; dx++, alpha += 8) {int j, sx = xofs[dx] - cn * 3;WT v = 0;for (j = 0; j < 8; j++) {int sxj = sx + j*cn;if ((unsigned)sxj >= (unsigned)swidth) {while (sxj < 0)sxj += cn;while (sxj >= swidth)sxj -= cn;}v += S[sxj] * alpha[j];}D[dx] = v;}if (limit == dwidth)break;for (; dx < xmax; dx++, alpha += 8) {int sx = xofs[dx];D[dx] = S[sx - cn * 3] * alpha[0] + S[sx - cn * 2] * alpha[1] +S[sx - cn] * alpha[2] + S[sx] * alpha[3] +S[sx + cn] * alpha[4] + S[sx + cn * 2] * alpha[5] +S[sx + cn * 3] * alpha[6] + S[sx + cn * 4] * alpha[7];}limit = dwidth;}alpha -= dwidth * 8;}}};template<typename T, typename WT, typename AT, class CastOp>struct VResizeLanczos4{typedef T value_type;typedef WT buf_type;typedef AT alpha_type;void operator()(const WT** src, T* dst, const AT* beta, int width) const{CastOp castOp;int k, x = 0;for (; x <= width - 4; x += 4) {WT b = beta[0];const WT* S = src[0];WT s0 = S[x] * b, s1 = S[x + 1] * b, s2 = S[x + 2] * b, s3 = S[x + 3] * b;for (k = 1; k < 8; k++) {b = beta[k]; S = src[k];s0 += S[x] * b; s1 += S[x + 1] * b;s2 += S[x + 2] * b; s3 += S[x + 3] * b;}dst[x] = castOp(s0); dst[x + 1] = castOp(s1);dst[x + 2] = castOp(s2); dst[x + 3] = castOp(s3);}for (; x < width; x++) {dst[x] = castOp(src[0][x] * beta[0] + src[1][x] * beta[1] +src[2][x] * beta[2] + src[3][x] * beta[3] + src[4][x] * beta[4] +src[5][x] * beta[5] + src[6][x] * beta[6] + src[7][x] * beta[7]);}}};template<typename T>struct ResizeAreaFastVec{ResizeAreaFastVec(int _scale_x, int _scale_y, int _cn, int _step) :scale_x(_scale_x), scale_y(_scale_y), cn(_cn), step(_step){fast_mode = scale_x == 2 && scale_y == 2 && (cn == 1 || cn == 3 || cn == 4);}int operator() (const T* S, T* D, int w) const{if (!fast_mode) {return 0;}const T* nextS = (const T*)((const uchar*)S + step);int dx = 0;if (cn == 1) {for (; dx < w; ++dx) {int index = dx * 2;D[dx] = (T)((S[index] + S[index + 1] + nextS[index] + nextS[index + 1] + 2) >> 2);}}else if (cn == 3) {for (; dx < w; dx += 3) {int index = dx * 2;D[dx] = (T)((S[index] + S[index + 3] + nextS[index] + nextS[index + 3] + 2) >> 2);D[dx + 1] = (T)((S[index + 1] + S[index + 4] + nextS[index + 1] + nextS[index + 4] + 2) >> 2);D[dx + 2] = (T)((S[index + 2] + S[index + 5] + nextS[index + 2] + nextS[index + 5] + 2) >> 2);}} else {FBC_Assert(cn == 4);for (; dx < w; dx += 4) {int index = dx * 2;D[dx] = (T)((S[index] + S[index + 4] + nextS[index] + nextS[index + 4] + 2) >> 2);D[dx + 1] = (T)((S[index + 1] + S[index + 5] + nextS[index + 1] + nextS[index + 5] + 2) >> 2);D[dx + 2] = (T)((S[index + 2] + S[index + 6] + nextS[index + 2] + nextS[index + 6] + 2) >> 2);D[dx + 3] = (T)((S[index + 3] + S[index + 7] + nextS[index + 3] + nextS[index + 7] + 2) >> 2);}}return dx;}private:int scale_x, scale_y;int cn;bool fast_mode;int step;};template<typename _Tp, typename value_type, typename buf_type, typename alpha_type, int chs>static void resizeGeneric_Linear(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst,const int* xofs, const void* _alpha, const int* yofs, const void* _beta, int xmin, int xmax, int ksize, int ONE){Size ssize = src.size(), dsize = dst.size();int dy, cn = src.channels;ssize.width *= cn;dsize.width *= cn;xmin *= cn;xmax *= cn;// image resize is a separable operation. In case of not too strongRange range(0, dsize.height);int bufstep = (int)alignSize(dsize.width, 16);AutoBuffer<buf_type> _buffer(bufstep*ksize);const value_type* srows[MAX_ESIZE] = { 0 };buf_type* rows[MAX_ESIZE] = { 0 };int prev_sy[MAX_ESIZE];for (int k = 0; k < ksize; k++) {prev_sy[k] = -1;rows[k] = (buf_type*)_buffer + bufstep*k;}const alpha_type* beta = (const alpha_type*)_beta + ksize * range.start;HResizeLinear<value_type, buf_type, alpha_type> hresize;VResizeLinear<value_type, buf_type, alpha_type, FixedPtCast<int, uchar, INTER_RESIZE_COEF_BITS * 2>> vresize1;VResizeLinear<value_type, buf_type, alpha_type, Cast<float, float>> vresize2;for (dy = range.start; dy < range.end; dy++, beta += ksize) {int sy0 = yofs[dy], k0 = ksize, k1 = 0, ksize2 = ksize / 2;for (int k = 0; k < ksize; k++) {int sy = clip<int>(sy0 - ksize2 + 1 + k, 0, ssize.height);for (k1 = std::max(k1, k); k1 < ksize; k1++) {if (sy == prev_sy[k1]) { // if the sy-th row has been computed already, reuse it.if (k1 > k) {memcpy(rows[k], rows[k1], bufstep*sizeof(rows[0][0]));}break;}}if (k1 == ksize) {k0 = std::min(k0, k); // remember the first row that needs to be computed}srows[k] = (const value_type*)src.ptr(sy);prev_sy[k] = sy;}if (k0 < ksize) {hresize((const value_type**)(srows + k0), (buf_type**)(rows + k0), ksize - k0, xofs, (const alpha_type*)(_alpha),ssize.width, dsize.width, cn, xmin, xmax, ONE);}if (sizeof(_Tp) == 1) { // ucharvresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);} else { // floatvresize2((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);}}}template<typename _Tp, typename value_type, typename buf_type, typename alpha_type, int chs>static void resizeGeneric_Cubic(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst,const int* xofs, const void* _alpha, const int* yofs, const void* _beta, int xmin, int xmax, int ksize){Size ssize = src.size(), dsize = dst.size();int dy, cn = src.channels;ssize.width *= cn;dsize.width *= cn;xmin *= cn;xmax *= cn;// image resize is a separable operation. In case of not too strongRange range(0, dsize.height);int bufstep = (int)alignSize(dsize.width, 16);AutoBuffer<buf_type> _buffer(bufstep*ksize);const value_type* srows[MAX_ESIZE] = { 0 };buf_type* rows[MAX_ESIZE] = { 0 };int prev_sy[MAX_ESIZE];for (int k = 0; k < ksize; k++) {prev_sy[k] = -1;rows[k] = (buf_type*)_buffer + bufstep*k;}const alpha_type* beta = (const alpha_type*)_beta + ksize * range.start;HResizeCubic<value_type, buf_type, alpha_type> hresize;VResizeCubic<value_type, buf_type, alpha_type, FixedPtCast<int, uchar, INTER_RESIZE_COEF_BITS * 2>> vresize1;VResizeCubic<value_type, buf_type, alpha_type, Cast<float, float>> vresize2;for (dy = range.start; dy < range.end; dy++, beta += ksize) {int sy0 = yofs[dy], k0 = ksize, k1 = 0, ksize2 = ksize / 2;for (int k = 0; k < ksize; k++) {int sy = clip<int>(sy0 - ksize2 + 1 + k, 0, ssize.height);for (k1 = std::max(k1, k); k1 < ksize; k1++) {if (sy == prev_sy[k1]) { // if the sy-th row has been computed already, reuse it.if (k1 > k) {memcpy(rows[k], rows[k1], bufstep*sizeof(rows[0][0]));}break;}}if (k1 == ksize) {k0 = std::min(k0, k); // remember the first row that needs to be computed}srows[k] = (const value_type*)src.ptr(sy);prev_sy[k] = sy;}if (k0 < ksize) {hresize((const value_type**)(srows + k0), (buf_type**)(rows + k0), ksize - k0, xofs, (const alpha_type*)(_alpha),ssize.width, dsize.width, cn, xmin, xmax);}if (sizeof(_Tp) == 1) { // ucharvresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);} else { // floatvresize2((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);}}}template<typename _Tp, typename value_type, typename buf_type, typename alpha_type, int chs>static void resizeGeneric_Lanczos4(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst,const int* xofs, const void* _alpha, const int* yofs, const void* _beta, int xmin, int xmax, int ksize){Size ssize = src.size(), dsize = dst.size();int dy, cn = src.channels;ssize.width *= cn;dsize.width *= cn;xmin *= cn;xmax *= cn;// image resize is a separable operation. In case of not too strongRange range(0, dsize.height);int bufstep = (int)alignSize(dsize.width, 16);AutoBuffer<buf_type> _buffer(bufstep*ksize);const value_type* srows[MAX_ESIZE] = { 0 };buf_type* rows[MAX_ESIZE] = { 0 };int prev_sy[MAX_ESIZE];for (int k = 0; k < ksize; k++) {prev_sy[k] = -1;rows[k] = (buf_type*)_buffer + bufstep*k;}const alpha_type* beta = (const alpha_type*)_beta + ksize * range.start;HResizeLanczos4<value_type, buf_type, alpha_type> hresize;VResizeLanczos4<value_type, buf_type, alpha_type, FixedPtCast<int, uchar, INTER_RESIZE_COEF_BITS * 2>> vresize1;VResizeLanczos4<value_type, buf_type, alpha_type, Cast<float, float>> vresize2;for (dy = range.start; dy < range.end; dy++, beta += ksize) {int sy0 = yofs[dy], k0 = ksize, k1 = 0, ksize2 = ksize / 2;for (int k = 0; k < ksize; k++) {int sy = clip<int>(sy0 - ksize2 + 1 + k, 0, ssize.height);for (k1 = std::max(k1, k); k1 < ksize; k1++) {if (sy == prev_sy[k1]) { // if the sy-th row has been computed already, reuse it.if (k1 > k) {memcpy(rows[k], rows[k1], bufstep*sizeof(rows[0][0]));}break;}}if (k1 == ksize) {k0 = std::min(k0, k); // remember the first row that needs to be computed}srows[k] = (const value_type*)src.ptr(sy);prev_sy[k] = sy;}if (k0 < ksize) {hresize((const value_type**)(srows + k0), (buf_type**)(rows + k0), ksize - k0, xofs, (const alpha_type*)(_alpha),ssize.width, dsize.width, cn, xmin, xmax);}if (sizeof(_Tp) == 1) { // ucharvresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);}else { // floatvresize2((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);}}}template<typename _Tp, typename T, typename WT, int chs>static void resizeGeneric_Area(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst,const DecimateAlpha* xtab0, int xtab_size0, const DecimateAlpha* ytab, int ytab_size, const int* tabofs){Size dsize = dst.size();int cn = dst.channels;Range range(0, dsize.height);dsize.width *= cn;AutoBuffer<WT> _buffer(dsize.width * 2);const DecimateAlpha* xtab = xtab0;int xtab_size = xtab_size0;WT *buf = _buffer, *sum = buf + dsize.width;int j_start = tabofs[range.start], j_end = tabofs[range.end], j, k, dx, prev_dy = ytab[j_start].di;for (dx = 0; dx < dsize.width; dx++) {sum[dx] = (WT)0;}for (j = j_start; j < j_end; j++) {WT beta = ytab[j].alpha;int dy = ytab[j].di;int sy = ytab[j].si;const T* S = (const T*)src.ptr(sy);for (dx = 0; dx < dsize.width; dx++) {buf[dx] = (WT)0;}if (cn == 1) {for (k = 0; k < xtab_size; k++) {int dxn = xtab[k].di;WT alpha = xtab[k].alpha;buf[dxn] += S[xtab[k].si] * alpha;}} else if (cn == 2) {for (k = 0; k < xtab_size; k++) {int sxn = xtab[k].si;int dxn = xtab[k].di;WT alpha = xtab[k].alpha;WT t0 = buf[dxn] + S[sxn] * alpha;WT t1 = buf[dxn + 1] + S[sxn + 1] * alpha;buf[dxn] = t0; buf[dxn + 1] = t1;}} else if (cn == 3) {for (k = 0; k < xtab_size; k++) {int sxn = xtab[k].si;int dxn = xtab[k].di;WT alpha = xtab[k].alpha;WT t0 = buf[dxn] + S[sxn] * alpha;WT t1 = buf[dxn + 1] + S[sxn + 1] * alpha;WT t2 = buf[dxn + 2] + S[sxn + 2] * alpha;buf[dxn] = t0; buf[dxn + 1] = t1; buf[dxn + 2] = t2;}} else if (cn == 4) {for (k = 0; k < xtab_size; k++) {int sxn = xtab[k].si;int dxn = xtab[k].di;WT alpha = xtab[k].alpha;WT t0 = buf[dxn] + S[sxn] * alpha;WT t1 = buf[dxn + 1] + S[sxn + 1] * alpha;buf[dxn] = t0; buf[dxn + 1] = t1;t0 = buf[dxn + 2] + S[sxn + 2] * alpha;t1 = buf[dxn + 3] + S[sxn + 3] * alpha;buf[dxn + 2] = t0; buf[dxn + 3] = t1;}} else {for (k = 0; k < xtab_size; k++) {int sxn = xtab[k].si;int dxn = xtab[k].di;WT alpha = xtab[k].alpha;for (int c = 0; c < cn; c++)buf[dxn + c] += S[sxn + c] * alpha;}}if (dy != prev_dy) {T* D = (T*)dst.ptr(prev_dy);for (dx = 0; dx < dsize.width; dx++) {D[dx] = saturate_cast<T>(sum[dx]);sum[dx] = beta*buf[dx];}prev_dy = dy;} else {for (dx = 0; dx < dsize.width; dx++) {sum[dx] += beta*buf[dx];}}}T* D = (T*)dst.ptr(prev_dy);for (dx = 0; dx < dsize.width; dx++) {D[dx] = saturate_cast<T>(sum[dx]);}}template<typename _Tp, typename T, typename WT, int chs>static void resizeGeneric_AreaFast(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst,const int* ofs, const int* xofs, int scale_x, int scale_y){Size ssize = src.size(), dsize = dst.size();int cn = src.channels;Range range(0, dsize.height);int area = scale_x*scale_y;float scale = 1.f / (area);int dwidth1 = (ssize.width / scale_x)*cn;dsize.width *= cn;ssize.width *= cn;int dy, dx, k = 0;ResizeAreaFastVec<uchar> vop(scale_x, scale_y, src.channels, (int)src.step);for (dy = range.start; dy < range.end; dy++) {T* D = (T*)(dst.data + dst.step*dy);int sy0 = dy*scale_y;int w = sy0 + scale_y <= ssize.height ? dwidth1 : 0;if (sy0 >= ssize.height) {for (dx = 0; dx < dsize.width; dx++) {D[dx] = 0;}continue;}dx = sizeof(_Tp) == 1 ? vop(src.ptr(sy0), (uchar*)D, w) : 0;for (; dx < w; dx++) {const T* S = (const T*)src.ptr(sy0) +xofs[dx];WT sum = 0;k = 0;for (; k <= area - 4; k += 4) {sum += S[ofs[k]] + S[ofs[k + 1]] + S[ofs[k + 2]] + S[ofs[k + 3]];}for (; k < area; k++) {sum += S[ofs[k]];}D[dx] = saturate_cast<T>(sum * scale);}for (; dx < dsize.width; dx++) {WT sum = 0;int count = 0, sx0 = xofs[dx];if (sx0 >= ssize.width) {D[dx] = 0;}for (int sy = 0; sy < scale_y; sy++) {if (sy0 + sy >= ssize.height) {break;}const T* S = (const T*)src.ptr(sy0 + sy) + sx0;for (int sx = 0; sx < scale_x*cn; sx += cn) {if (sx0 + sx >= ssize.width) {break;}sum += S[sx];count++;}}D[dx] = saturate_cast<T>((float)sum / count);}}}template<typename _Tp>static void interpolateCubic(_Tp x, _Tp* coeffs){const float A = -0.75f;coeffs[0] = ((A*(x + 1) - 5 * A)*(x + 1) + 8 * A)*(x + 1) - 4 * A;coeffs[1] = ((A + 2)*x - (A + 3))*x*x + 1;coeffs[2] = ((A + 2)*(1 - x) - (A + 3))*(1 - x)*(1 - x) + 1;coeffs[3] = 1.f - coeffs[0] - coeffs[1] - coeffs[2];}template<typename _Tp>static void interpolateLanczos4(_Tp x, _Tp* coeffs){static const double s45 = 0.70710678118654752440084436210485;static const double cs[][2] = { { 1, 0 }, { -s45, -s45 }, { 0, 1 }, { s45, -s45 }, { -1, 0 }, { s45, s45 }, { 0, -1 }, { -s45, s45 } };if (x < FLT_EPSILON) {for (int i = 0; i < 8; i++) {coeffs[i] = 0;}coeffs[3] = 1;return;}float sum = 0;double y0 = -(x + 3)*FBC_PI*0.25, s0 = sin(y0), c0 = cos(y0);for (int i = 0; i < 8; i++) {double y = -(x + 3 - i)*FBC_PI*0.25;coeffs[i] = (float)((cs[i][0] * s0 + cs[i][1] * c0) / (y*y));sum += coeffs[i];}sum = 1.f / sum;for (int i = 0; i < 8; i++) {coeffs[i] *= sum;}}template<typename _Tp, int chs>static int resize_nearest(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst){Size ssize = src.size();Size dsize = dst.size();double fx = (double)dsize.width / ssize.width;double fy = (double)dsize.height / ssize.height;AutoBuffer<int> _x_ofs(dsize.width);int* x_ofs = _x_ofs;int pix_size = (int)src.elemSize();int pix_size4 = (int)(pix_size / sizeof(int));double ifx = 1. / fx, ify = 1. / fy;for (int x = 0; x < dsize.width; x++) {int sx = fbcFloor(x*ifx);x_ofs[x] = std::min(sx, ssize.width - 1)*pix_size;}Range range(0, dsize.height);int x, y;for (y = range.start; y < range.end; y++) {uchar* D = dst.data + dst.step*y;int sy = std::min(fbcFloor(y*ify), ssize.height - 1);const uchar* S = src.ptr(sy);switch (pix_size) {case 1:for (x = 0; x <= dsize.width - 2; x += 2) {uchar t0 = S[x_ofs[x]];uchar t1 = S[x_ofs[x + 1]];D[x] = t0;D[x + 1] = t1;}for (; x < dsize.width; x++) {D[x] = S[x_ofs[x]];}break;case 2:for (x = 0; x < dsize.width; x++) {*(ushort*)(D + x * 2) = *(ushort*)(S + x_ofs[x]);}break;case 3:for (x = 0; x < dsize.width; x++, D += 3) {const uchar* _tS = S + x_ofs[x];D[0] = _tS[0]; D[1] = _tS[1]; D[2] = _tS[2];}break;case 4:for (x = 0; x < dsize.width; x++) {*(int*)(D + x * 4) = *(int*)(S + x_ofs[x]);}break;case 6:for (x = 0; x < dsize.width; x++, D += 6) {const ushort* _tS = (const ushort*)(S + x_ofs[x]);ushort* _tD = (ushort*)D;_tD[0] = _tS[0]; _tD[1] = _tS[1]; _tD[2] = _tS[2];}break;case 8:for (x = 0; x < dsize.width; x++, D += 8) {const int* _tS = (const int*)(S + x_ofs[x]);int* _tD = (int*)D;_tD[0] = _tS[0]; _tD[1] = _tS[1];}break;case 12:for (x = 0; x < dsize.width; x++, D += 12) {const int* _tS = (const int*)(S + x_ofs[x]);int* _tD = (int*)D;_tD[0] = _tS[0]; _tD[1] = _tS[1]; _tD[2] = _tS[2];}break;default:for (x = 0; x < dsize.width; x++, D += pix_size) {const int* _tS = (const int*)(S + x_ofs[x]);int* _tD = (int*)D;for (int k = 0; k < pix_size4; k++)_tD[k] = _tS[k];}}}return 0;}template<typename _Tp, int chs>static int resize_linear(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst){Size ssize = src.size();Size dsize = dst.size();double inv_scale_x = (double)dsize.width / ssize.width;double inv_scale_y = (double)dsize.height / ssize.height;double scale_x = 1. / inv_scale_x, scale_y = 1. / inv_scale_y;int iscale_x = saturate_cast<int>(scale_x);int iscale_y = saturate_cast<int>(scale_y);bool is_area_fast = std::abs(scale_x - iscale_x) < DBL_EPSILON && std::abs(scale_y - iscale_y) < DBL_EPSILON;// in case of scale_x && scale_y is equal to 2// INTER_AREA (fast) also is equal to INTER_LINEARif (is_area_fast && iscale_x == 2 && iscale_y == 2) {resize_area(src, dst);return 0;}int cn = dst.channels;int k, sx, sy, dx, dy;int xmin = 0, xmax = dsize.width, width = dsize.width*cn;bool fixpt = sizeof(_Tp) == 1 ? true : false;float fx, fy;int ksize = 2, ksize2;ksize2 = ksize / 2;AutoBuffer<uchar> _buffer((width + dsize.height)*(sizeof(int) + sizeof(float)*ksize));int* xofs = (int*)(uchar*)_buffer;int* yofs = xofs + width;float* alpha = (float*)(yofs + dsize.height);short* ialpha = (short*)alpha;float* beta = alpha + width*ksize;short* ibeta = ialpha + width*ksize;float cbuf[MAX_ESIZE];for (dx = 0; dx < dsize.width; dx++) {fx = (float)((dx + 0.5)*scale_x - 0.5);sx = fbcFloor(fx);fx -= sx;if (sx < ksize2 - 1) {xmin = dx + 1;if (sx < 0) {fx = 0, sx = 0;}}if (sx + ksize2 >= ssize.width) {xmax = std::min(xmax, dx);if (sx >= ssize.width - 1) {fx = 0, sx = ssize.width - 1;}}for (k = 0, sx *= cn; k < cn; k++) {xofs[dx*cn + k] = sx + k;}cbuf[0] = 1.f - fx;cbuf[1] = fx;if (fixpt) {for (k = 0; k < ksize; k++) {ialpha[dx*cn*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}for (; k < cn*ksize; k++) {ialpha[dx*cn*ksize + k] = ialpha[dx*cn*ksize + k - ksize];}} else {for (k = 0; k < ksize; k++) {alpha[dx*cn*ksize + k] = cbuf[k];}for (; k < cn*ksize; k++) {alpha[dx*cn*ksize + k] = alpha[dx*cn*ksize + k - ksize];}}}for (dy = 0; dy < dsize.height; dy++) {fy = (float)((dy + 0.5)*scale_y - 0.5);sy = fbcFloor(fy);fy -= sy;yofs[dy] = sy;cbuf[0] = 1.f - fy;cbuf[1] = fy;if (fixpt) {for (k = 0; k < ksize; k++) {ibeta[dy*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}} else {for (k = 0; k < ksize; k++) {beta[dy*ksize + k] = cbuf[k];}}}if (sizeof(_Tp) == 1) { // uchartypedef uchar value_type; // HResizeLinear/VResizeLineartypedef int buf_type;typedef short alpha_type;int ONE = INTER_RESIZE_COEF_SCALE;resizeGeneric_Linear<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize, ONE);} else if (sizeof(_Tp) == 4) { // floattypedef float value_type; // HResizeLinear/VResizeLineartypedef float buf_type;typedef float alpha_type;int ONE = 1;resizeGeneric_Linear<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize, ONE);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}template<typename _Tp, int chs>static int resize_cubic(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst){Size ssize = src.size();Size dsize = dst.size();double inv_scale_x = (double)dsize.width / ssize.width;double inv_scale_y = (double)dsize.height / ssize.height;double scale_x = 1. / inv_scale_x, scale_y = 1. / inv_scale_y;int cn = dst.channels;int k, sx, sy, dx, dy;int xmin = 0, xmax = dsize.width, width = dsize.width*cn;bool fixpt = sizeof(_Tp) == 1 ? true : false;float fx, fy;int ksize = 4, ksize2;ksize2 = ksize / 2;AutoBuffer<uchar> _buffer((width + dsize.height)*(sizeof(int) + sizeof(float)*ksize));int* xofs = (int*)(uchar*)_buffer;int* yofs = xofs + width;float* alpha = (float*)(yofs + dsize.height);short* ialpha = (short*)alpha;float* beta = alpha + width*ksize;short* ibeta = ialpha + width*ksize;float cbuf[MAX_ESIZE];for (dx = 0; dx < dsize.width; dx++) {fx = (float)((dx + 0.5)*scale_x - 0.5);sx = fbcFloor(fx);fx -= sx;if (sx < ksize2 - 1) {xmin = dx + 1;}if (sx + ksize2 >= ssize.width) {xmax = std::min(xmax, dx);}for (k = 0, sx *= cn; k < cn; k++) {xofs[dx*cn + k] = sx + k;}interpolateCubic<float>(fx, cbuf);if (fixpt) {for (k = 0; k < ksize; k++) {ialpha[dx*cn*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}for (; k < cn*ksize; k++) {ialpha[dx*cn*ksize + k] = ialpha[dx*cn*ksize + k - ksize];}} else {for (k = 0; k < ksize; k++) {alpha[dx*cn*ksize + k] = cbuf[k];}for (; k < cn*ksize; k++) {alpha[dx*cn*ksize + k] = alpha[dx*cn*ksize + k - ksize];}}}for (dy = 0; dy < dsize.height; dy++) {fy = (float)((dy + 0.5)*scale_y - 0.5);sy = cvFloor(fy);fy -= sy;yofs[dy] = sy;interpolateCubic<float>(fy, cbuf);if (fixpt) {for (k = 0; k < ksize; k++) {ibeta[dy*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}} else {for (k = 0; k < ksize; k++) {beta[dy*ksize + k] = cbuf[k];}}}if (sizeof(_Tp) == 1) { // uchartypedef uchar value_type; // HResizeCubic/VResizeCubictypedef int buf_type;typedef short alpha_type;resizeGeneric_Cubic<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize);} else if (sizeof(_Tp) == 4) { // floattypedef float value_type; // HResizeCubic/VResizeCubictypedef float buf_type;typedef float alpha_type;resizeGeneric_Cubic<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}template<typename _Tp, int chs>static int resize_area(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst){Size ssize = src.size();Size dsize = dst.size();int cn = dst.channels;double inv_scale_x = (double)dsize.width / ssize.width;double inv_scale_y = (double)dsize.height / ssize.height;double scale_x = 1. / inv_scale_x, scale_y = 1. / inv_scale_y;int iscale_x = saturate_cast<int>(scale_x);int iscale_y = saturate_cast<int>(scale_y);bool is_area_fast = std::abs(scale_x - iscale_x) < DBL_EPSILON && std::abs(scale_y - iscale_y) < DBL_EPSILON;int k, sx, sy, dx, dy;// true "area" interpolation is only implemented for the case (scale_x <= 1 && scale_y <= 1).// In other cases it is emulated using some variant of bilinear interpolationif (scale_x >= 1 && scale_y >= 1) {if (is_area_fast) {int area = iscale_x*iscale_y;size_t srcstep = src.step / sizeof(_Tp);AutoBuffer<int> _ofs(area + dsize.width*cn);int* ofs = _ofs;int* xofs = ofs + area;for (sy = 0, k = 0; sy < iscale_y; sy++) {for (sx = 0; sx < iscale_x; sx++) {ofs[k++] = (int)(sy*srcstep + sx*cn);}}for (dx = 0; dx < dsize.width; dx++) {int j = dx * cn;sx = iscale_x * j;for (k = 0; k < cn; k++) {xofs[j + k] = sx + k;}}if (sizeof(_Tp) == 1) { // uchartypedef uchar T;typedef int WT;resizeGeneric_AreaFast<_Tp, T, WT, chs>(src, dst, ofs, xofs, iscale_x, iscale_y);} else if (sizeof(_Tp) == 4) { // floattypedef float T;typedef float WT;resizeGeneric_AreaFast<_Tp, T, WT, chs>(src, dst, ofs, xofs, iscale_x, iscale_y);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}FBC_Assert(cn <= 4);AutoBuffer<DecimateAlpha> _xytab((ssize.width + ssize.height) * 2);DecimateAlpha* xtab = _xytab, *ytab = xtab + ssize.width * 2;int xtab_size = computeResizeAreaTab<int>(ssize.width, dsize.width, cn, scale_x, xtab);int ytab_size = computeResizeAreaTab<int>(ssize.height, dsize.height, 1, scale_y, ytab);AutoBuffer<int> _tabofs(dsize.height + 1);int* tabofs = _tabofs;for (k = 0, dy = 0; k < ytab_size; k++) {if (k == 0 || ytab[k].di != ytab[k - 1].di) {assert(ytab[k].di == dy);tabofs[dy++] = k;}}tabofs[dy] = ytab_size;if (sizeof(_Tp) == 1) { // uchartypedef uchar T;typedef float WT;resizeGeneric_Area<_Tp, T, WT, chs>(src, dst, xtab, xtab_size, ytab, ytab_size, tabofs);} else if (sizeof(_Tp) == 4) { // floattypedef float T;typedef float WT;resizeGeneric_Area<_Tp, T, WT, chs>(src, dst, xtab, xtab_size, ytab, ytab_size, tabofs);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}int xmin = 0, xmax = dsize.width, width = dsize.width*cn;bool fixpt = sizeof(_Tp) == 1 ? true : false;float fx, fy;int ksize = 2, ksize2;ksize2 = ksize / 2;AutoBuffer<uchar> _buffer((width + dsize.height)*(sizeof(int) + sizeof(float)*ksize));int* xofs = (int*)(uchar*)_buffer;int* yofs = xofs + width;float* alpha = (float*)(yofs + dsize.height);short* ialpha = (short*)alpha;float* beta = alpha + width*ksize;short* ibeta = ialpha + width*ksize;float cbuf[MAX_ESIZE];for (dx = 0; dx < dsize.width; dx++) {sx = fbcFloor(dx*scale_x);fx = (float)((dx + 1) - (sx + 1)*inv_scale_x);fx = fx <= 0 ? 0.f : fx - fbcFloor(fx);if (sx < ksize2 - 1) {xmin = dx + 1;if (sx < 0) {fx = 0, sx = 0;}}if (sx + ksize2 >= ssize.width) {xmax = std::min(xmax, dx);if (sx >= ssize.width - 1) {fx = 0, sx = ssize.width - 1;}}for (k = 0, sx *= cn; k < cn; k++) {xofs[dx*cn + k] = sx + k;}cbuf[0] = 1.f - fx;cbuf[1] = fx;if (fixpt) {for (k = 0; k < ksize; k++) {ialpha[dx*cn*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}for (; k < cn*ksize; k++) {ialpha[dx*cn*ksize + k] = ialpha[dx*cn*ksize + k - ksize];}} else {for (k = 0; k < ksize; k++) {alpha[dx*cn*ksize + k] = cbuf[k];}for (; k < cn*ksize; k++) {alpha[dx*cn*ksize + k] = alpha[dx*cn*ksize + k - ksize];}}}for (dy = 0; dy < dsize.height; dy++) {sy = fbcFloor(dy*scale_y);fy = (float)((dy + 1) - (sy + 1)*inv_scale_y);fy = fy <= 0 ? 0.f : fy - fbcFloor(fy);yofs[dy] = sy;cbuf[0] = 1.f - fy;cbuf[1] = fy;if (fixpt) {for (k = 0; k < ksize; k++) {ibeta[dy*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);}} else {for (k = 0; k < ksize; k++) {beta[dy*ksize + k] = cbuf[k];}}}if (sizeof(_Tp) == 1) { // uchartypedef uchar value_type; // HResizeLinear/VResizeLineartypedef int buf_type;typedef short alpha_type;int ONE = INTER_RESIZE_COEF_SCALE;resizeGeneric_Linear<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize, ONE);} else if (sizeof(_Tp) == 4) { // floattypedef float value_type; // HResizeLinear/VResizeLineartypedef float buf_type;typedef float alpha_type;int ONE = 1;resizeGeneric_Linear<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize, ONE);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}template<typename _Tp, int chs>static int resize_lanczos4(const Mat_<_Tp, chs>& src, Mat_<_Tp, chs>& dst){Size ssize = src.size();Size dsize = dst.size();double inv_scale_x = (double)dsize.width / ssize.width;double inv_scale_y = (double)dsize.height / ssize.height;double scale_x = 1. / inv_scale_x, scale_y = 1. / inv_scale_y;int cn = dst.channels;int k, sx, sy, dx, dy;int xmin = 0, xmax = dsize.width, width = dsize.width*cn;bool fixpt = sizeof(_Tp) == 1 ? true : false;float fx, fy;int ksize = 8, ksize2;ksize2 = ksize / 2;AutoBuffer<uchar> _buffer((width + dsize.height)*(sizeof(int) + sizeof(float)*ksize));int* xofs = (int*)(uchar*)_buffer;int* yofs = xofs + width;float* alpha = (float*)(yofs + dsize.height);short* ialpha = (short*)alpha;float* beta = alpha + width*ksize;short* ibeta = ialpha + width*ksize;float cbuf[MAX_ESIZE];for (dx = 0; dx < dsize.width; dx++) {fx = (float)((dx + 0.5)*scale_x - 0.5);sx = fbcFloor(fx);fx -= sx;if (sx < ksize2 - 1) {xmin = dx + 1;}if (sx + ksize2 >= ssize.width) {xmax = std::min(xmax, dx);}for (k = 0, sx *= cn; k < cn; k++) {xofs[dx*cn + k] = sx + k;}interpolateLanczos4<float>(fx, cbuf);if (fixpt) {for (k = 0; k < ksize; k++)ialpha[dx*cn*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);for (; k < cn*ksize; k++)ialpha[dx*cn*ksize + k] = ialpha[dx*cn*ksize + k - ksize];} else {for (k = 0; k < ksize; k++)alpha[dx*cn*ksize + k] = cbuf[k];for (; k < cn*ksize; k++)alpha[dx*cn*ksize + k] = alpha[dx*cn*ksize + k - ksize];}}for (dy = 0; dy < dsize.height; dy++) {fy = (float)((dy + 0.5)*scale_y - 0.5);sy = fbcFloor(fy);fy -= sy;yofs[dy] = sy;interpolateLanczos4<float>(fy, cbuf);if (fixpt){for (k = 0; k < ksize; k++)ibeta[dy*ksize + k] = saturate_cast<short>(cbuf[k] * INTER_RESIZE_COEF_SCALE);} else {for (k = 0; k < ksize; k++)beta[dy*ksize + k] = cbuf[k];}}if (sizeof(_Tp) == 1) { // uchartypedef uchar value_type; // HResizeLanczos4/VResizeLanczos4typedef int buf_type;typedef short alpha_type;resizeGeneric_Lanczos4<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize);} else if (sizeof(_Tp) == 4) { // floattypedef float value_type; // HResizeLanczos4/VResizeLanczos4typedef float buf_type;typedef float alpha_type;resizeGeneric_Lanczos4<_Tp, value_type, buf_type, alpha_type, chs>(src, dst,xofs, fixpt ? (void*)ialpha : (void*)alpha, yofs, fixpt ? (void*)ibeta : (void*)beta, xmin, xmax, ksize);} else {fprintf(stderr, "not support type\n");return -1;}return 0;}} // namespace fbc#endif // FBC_CV_RESIZE_HPP_

测试代码test_resize.cpp:

#include <assert.h>#include <core/mat.hpp>#include <resize.hpp>#include <opencv2/opencv.hpp>#include "test_resize.hpp"int test_resize_uchar(){cv::Mat mat = cv::imread("E:/GitCode/OpenCV_Test/test_images/lena.png", 1);if (!mat.data) {std::cout << "read image fail" << std::endl;return -1;}int width = 23, height = 11;for (int inter = 0; inter < 5; inter++) {fbc::Mat3BGR mat1(mat.rows, mat.cols, mat.data);fbc::Mat3BGR mat2(mat1);fbc::Mat3BGR mat3(height, width);fbc::resize(mat2, mat3, inter);cv::Mat mat1_(mat.rows, mat.cols, CV_8UC3, mat.data);cv::Mat mat2_;mat1_.copyTo(mat2_);cv::Mat mat3_(height, width, CV_8UC3);cv::resize(mat2_, mat3_, cv::Size(width, height), 0, 0, inter);assert(mat3.step == mat3_.step);for (int y = 0; y < mat3.rows; y++) {const fbc::uchar* p = mat3.ptr(y);const uchar* p_ = mat3_.ptr(y);for (int x = 0; x < mat3.step; x++) {assert(p[x] == p_[x]);}}}return 0;}int test_resize_float(){cv::Mat mat = cv::imread("E:/GitCode/OpenCV_Test/test_images/lena.png", 1);if (!mat.data) {std::cout << "read image fail" << std::endl;return -1;}int width = 623, height = 711;cv::cvtColor(mat, mat, CV_BGR2GRAY);mat.convertTo(mat, CV_32FC1);for (int inter = 0; inter < 5; inter++) {fbc::Mat_<float, 1> mat1(mat.rows, mat.cols, mat.data);fbc::Mat_<float, 1> mat2(mat1);fbc::Mat_<float, 1> mat3(height, width);fbc::resize(mat2, mat3, inter);cv::Mat mat1_(mat.rows, mat.cols, CV_32FC1, mat.data);cv::Mat mat2_;mat1_.copyTo(mat2_);cv::Mat mat3_(height, width, CV_32FC1);cv::resize(mat2_, mat3_, cv::Size(width, height), 0, 0, inter);assert(mat3.step == mat3_.step);for (int y = 0; y < mat3.rows; y++) {const fbc::uchar* p = mat3.ptr(y);const uchar* p_ = mat3_.ptr(y);for (int x = 0; x < mat3.step; x++) {assert(p[x] == p_[x]);}}}return 0;}int test_resize_area(){cv::Mat mat = cv::imread("E:/GitCode/OpenCV_Test/test_images/lena.png", 1);if (!mat.data) {std::cout << "read image fail" << std::endl;return -1;}fbc::Size size[3] = {fbc::Size(123, 111), fbc::Size(256, 256), fbc::Size(723, 817)};for (int i = 0; i < 3; i++) {fbc::Mat3BGR mat1(mat.rows, mat.cols, mat.data);fbc::Mat3BGR mat2(mat1);fbc::Mat3BGR mat3(size[i].height, size[i].width);fbc::resize(mat2, mat3, 3);cv::Mat mat1_(mat.rows, mat.cols, CV_8UC3, mat.data);cv::Mat mat2_;mat1_.copyTo(mat2_);cv::Mat mat3_(size[i].height, size[i].width, CV_8UC3);cv::resize(mat2_, mat3_, cv::Size(size[i].width, size[i].height), 0, 0, 3);assert(mat3.step == mat3_.step);for (int y = 0; y < mat3.rows; y++) {const fbc::uchar* p = mat3.ptr(y);const uchar* p_ = mat3_.ptr(y);for (int x = 0; x < mat3.step; x++) {assert(p[x] == p_[x]);}}}cv::Mat matf;cv::cvtColor(mat, matf, CV_BGR2GRAY);matf.convertTo(matf, CV_32FC1);for (int i = 0; i < 3; i++) {fbc::Mat_<float, 1> mat1(mat.rows, mat.cols, matf.data);fbc::Mat_<float, 1> mat2(mat1);fbc::Mat_<float, 1> mat3(size[i].height, size[i].width);fbc::resize(mat2, mat3, 3);cv::Mat mat1_(mat.rows, mat.cols, CV_32FC1, matf.data);cv::Mat mat2_;mat1_.copyTo(mat2_);cv::Mat mat3_(size[i].height, size[i].width, CV_32FC1);cv::resize(mat2_, mat3_, cv::Size(size[i].width, size[i].height), 0, 0, 3);assert(mat3.step == mat3_.step);for (int y = 0; y < mat3.rows; y++) {const fbc::uchar* p = mat3.ptr(y);const uchar* p_ = mat3_.ptr(y);for (int x = 0; x < mat3.step; x++) {assert(p[x] == p_[x]);}}}return 0;}

GitHub：https://github.com/fengbingchun/OpenCV_Test