OpenCV代码提取：resize函数的实现-赢咖4注册

aihot 2017-05-24 18:31:03 OpenCV | 查看评论

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是免费软件，并且使用与OpenCV相同的许可证
#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;
// 插值公式和表格
const 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);
// 将图像src调整到大小或达到指定的大小
// 支持类型：uchar / float
template<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 || float
Size ssize = src.size();
Size dsize = dst.size();
if (dsize == ssize) {
// 来源和目的地的大小相同。使用简单的副本.
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;
// 图像调整大小是一个可分离的操作。万一不太强
Range 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); // 记住需要计算的第一行
}
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) { // uchar
vresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);
} else { // float
vresize2((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;
// 图像调整大小是一个可分离的操作。万一不太强
Range 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); // 记住需要计算的第一行
}
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) { // uchar
vresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);
} else { // float
vresize2((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;
// 图像调整大小是一个可分离的操作。万一不太强
Range 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]) { // 如果已经计算了第sy行，则重新使用它.
if (k1 > k) {
memcpy(rows[k], rows[k1], bufstep*sizeof(rows[0][0]));
}
break;
}
}
if (k1 == ksize) {
k0 = std::min(k0, k); // 记住需要计算的第一行
}
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) { // uchar
vresize1((const buf_type**)rows, (value_type*)(dst.data + dst.step*dy), beta, dsize.width);
}
else { // float
vresize2((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;
// 在scale_x && scale_y等于2的情况下
// INTER_AREA（fast）也等于INTER_LINEAR
if (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) { // uchar
typedef uchar value_type; // HResizeLinear/VResizeLinear
typedef 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) { // float
typedef float value_type; // HResizeLinear/VResizeLinear
typedef 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) { // uchar
typedef uchar value_type; // HResizeCubic/VResizeCubic
typedef 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) { // float
typedef float value_type; // HResizeCubic/VResizeCubic
typedef 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;
// 仅对于情况（scale_x <= 1 && scale_y <= 1）才实现真实的“区域”插值。
// 在其他情况下，使用双线性插值的一些变体进行仿真
if (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) { // uchar
typedef uchar T;
typedef int WT;
resizeGeneric_AreaFast<_Tp, T, WT, chs>(src, dst, ofs, xofs, iscale_x, iscale_y);
} else if (sizeof(_Tp) == 4) { // float
typedef 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) { // uchar
typedef 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) { // float
typedef 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) { // uchar
typedef uchar value_type; // HResizeLinear/VResizeLinear
typedef 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) { // float
typedef float value_type; // HResizeLinear/VResizeLinear
typedef 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) { // uchar
typedef uchar value_type; // HResizeLanczos4/VResizeLanczos4
typedef 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) { // float
typedef float value_type; // HResizeLanczos4/VResizeLanczos4
typedef 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_

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