in modules/imgproc/src/imgwarp.cpp [3810:4018]
static void remapBilinear( const Mat& _src, Mat& _dst, const Mat& _xy,
const Mat& _fxy, const void* _wtab,
int borderType, const Scalar& _borderValue )
{
typedef typename CastOp::rtype T;
typedef typename CastOp::type1 WT;
Size ssize = _src.size(), dsize = _dst.size();
int k, cn = _src.channels();
const AT* wtab = (const AT*)_wtab;
const T* S0 = _src.ptr<T>();
size_t sstep = _src.step/sizeof(S0[0]);
T cval[CV_CN_MAX];
int dx, dy;
CastOp castOp;
VecOp vecOp;
for( k = 0; k < cn; k++ )
cval[k] = saturate_cast<T>(_borderValue[k & 3]);
unsigned width1 = std::max(ssize.width-1, 0), height1 = std::max(ssize.height-1, 0);
CV_Assert( ssize.area() > 0 );
#if CV_SSE2
if( _src.type() == CV_8UC3 )
width1 = std::max(ssize.width-2, 0);
#endif
for( dy = 0; dy < dsize.height; dy++ )
{
T* D = _dst.ptr<T>(dy);
const short* XY = _xy.ptr<short>(dy);
const ushort* FXY = _fxy.ptr<ushort>(dy);
int X0 = 0;
bool prevInlier = false;
for( dx = 0; dx <= dsize.width; dx++ )
{
bool curInlier = dx < dsize.width ?
(unsigned)XY[dx*2] < width1 &&
(unsigned)XY[dx*2+1] < height1 : !prevInlier;
if( curInlier == prevInlier )
continue;
int X1 = dx;
dx = X0;
X0 = X1;
prevInlier = curInlier;
if( !curInlier )
{
int len = vecOp( _src, D, XY + dx*2, FXY + dx, wtab, X1 - dx );
D += len*cn;
dx += len;
if( cn == 1 )
{
for( ; dx < X1; dx++, D++ )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
const AT* w = wtab + FXY[dx]*4;
const T* S = S0 + sy*sstep + sx;
*D = castOp(WT(S[0]*w[0] + S[1]*w[1] + S[sstep]*w[2] + S[sstep+1]*w[3]));
}
}
else if( cn == 2 )
for( ; dx < X1; dx++, D += 2 )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
const AT* w = wtab + FXY[dx]*4;
const T* S = S0 + sy*sstep + sx*2;
WT t0 = S[0]*w[0] + S[2]*w[1] + S[sstep]*w[2] + S[sstep+2]*w[3];
WT t1 = S[1]*w[0] + S[3]*w[1] + S[sstep+1]*w[2] + S[sstep+3]*w[3];
D[0] = castOp(t0); D[1] = castOp(t1);
}
else if( cn == 3 )
for( ; dx < X1; dx++, D += 3 )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
const AT* w = wtab + FXY[dx]*4;
const T* S = S0 + sy*sstep + sx*3;
WT t0 = S[0]*w[0] + S[3]*w[1] + S[sstep]*w[2] + S[sstep+3]*w[3];
WT t1 = S[1]*w[0] + S[4]*w[1] + S[sstep+1]*w[2] + S[sstep+4]*w[3];
WT t2 = S[2]*w[0] + S[5]*w[1] + S[sstep+2]*w[2] + S[sstep+5]*w[3];
D[0] = castOp(t0); D[1] = castOp(t1); D[2] = castOp(t2);
}
else if( cn == 4 )
for( ; dx < X1; dx++, D += 4 )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
const AT* w = wtab + FXY[dx]*4;
const T* S = S0 + sy*sstep + sx*4;
WT t0 = S[0]*w[0] + S[4]*w[1] + S[sstep]*w[2] + S[sstep+4]*w[3];
WT t1 = S[1]*w[0] + S[5]*w[1] + S[sstep+1]*w[2] + S[sstep+5]*w[3];
D[0] = castOp(t0); D[1] = castOp(t1);
t0 = S[2]*w[0] + S[6]*w[1] + S[sstep+2]*w[2] + S[sstep+6]*w[3];
t1 = S[3]*w[0] + S[7]*w[1] + S[sstep+3]*w[2] + S[sstep+7]*w[3];
D[2] = castOp(t0); D[3] = castOp(t1);
}
else
for( ; dx < X1; dx++, D += cn )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
const AT* w = wtab + FXY[dx]*4;
const T* S = S0 + sy*sstep + sx*cn;
for( k = 0; k < cn; k++ )
{
WT t0 = S[k]*w[0] + S[k+cn]*w[1] + S[sstep+k]*w[2] + S[sstep+k+cn]*w[3];
D[k] = castOp(t0);
}
}
}
else
{
if( borderType == BORDER_TRANSPARENT && cn != 3 )
{
D += (X1 - dx)*cn;
dx = X1;
continue;
}
if( cn == 1 )
for( ; dx < X1; dx++, D++ )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
if( borderType == BORDER_CONSTANT &&
(sx >= ssize.width || sx+1 < 0 ||
sy >= ssize.height || sy+1 < 0) )
{
D[0] = cval[0];
}
else
{
int sx0, sx1, sy0, sy1;
T v0, v1, v2, v3;
const AT* w = wtab + FXY[dx]*4;
if( borderType == BORDER_REPLICATE )
{
sx0 = clip(sx, 0, ssize.width);
sx1 = clip(sx+1, 0, ssize.width);
sy0 = clip(sy, 0, ssize.height);
sy1 = clip(sy+1, 0, ssize.height);
v0 = S0[sy0*sstep + sx0];
v1 = S0[sy0*sstep + sx1];
v2 = S0[sy1*sstep + sx0];
v3 = S0[sy1*sstep + sx1];
}
else
{
sx0 = borderInterpolate(sx, ssize.width, borderType);
sx1 = borderInterpolate(sx+1, ssize.width, borderType);
sy0 = borderInterpolate(sy, ssize.height, borderType);
sy1 = borderInterpolate(sy+1, ssize.height, borderType);
v0 = sx0 >= 0 && sy0 >= 0 ? S0[sy0*sstep + sx0] : cval[0];
v1 = sx1 >= 0 && sy0 >= 0 ? S0[sy0*sstep + sx1] : cval[0];
v2 = sx0 >= 0 && sy1 >= 0 ? S0[sy1*sstep + sx0] : cval[0];
v3 = sx1 >= 0 && sy1 >= 0 ? S0[sy1*sstep + sx1] : cval[0];
}
D[0] = castOp(WT(v0*w[0] + v1*w[1] + v2*w[2] + v3*w[3]));
}
}
else
for( ; dx < X1; dx++, D += cn )
{
int sx = XY[dx*2], sy = XY[dx*2+1];
if( borderType == BORDER_CONSTANT &&
(sx >= ssize.width || sx+1 < 0 ||
sy >= ssize.height || sy+1 < 0) )
{
for( k = 0; k < cn; k++ )
D[k] = cval[k];
}
else
{
int sx0, sx1, sy0, sy1;
const T *v0, *v1, *v2, *v3;
const AT* w = wtab + FXY[dx]*4;
if( borderType == BORDER_REPLICATE )
{
sx0 = clip(sx, 0, ssize.width);
sx1 = clip(sx+1, 0, ssize.width);
sy0 = clip(sy, 0, ssize.height);
sy1 = clip(sy+1, 0, ssize.height);
v0 = S0 + sy0*sstep + sx0*cn;
v1 = S0 + sy0*sstep + sx1*cn;
v2 = S0 + sy1*sstep + sx0*cn;
v3 = S0 + sy1*sstep + sx1*cn;
}
else if( borderType == BORDER_TRANSPARENT &&
((unsigned)sx >= (unsigned)(ssize.width-1) ||
(unsigned)sy >= (unsigned)(ssize.height-1)))
continue;
else
{
sx0 = borderInterpolate(sx, ssize.width, borderType);
sx1 = borderInterpolate(sx+1, ssize.width, borderType);
sy0 = borderInterpolate(sy, ssize.height, borderType);
sy1 = borderInterpolate(sy+1, ssize.height, borderType);
v0 = sx0 >= 0 && sy0 >= 0 ? S0 + sy0*sstep + sx0*cn : &cval[0];
v1 = sx1 >= 0 && sy0 >= 0 ? S0 + sy0*sstep + sx1*cn : &cval[0];
v2 = sx0 >= 0 && sy1 >= 0 ? S0 + sy1*sstep + sx0*cn : &cval[0];
v3 = sx1 >= 0 && sy1 >= 0 ? S0 + sy1*sstep + sx1*cn : &cval[0];
}
for( k = 0; k < cn; k++ )
D[k] = castOp(WT(v0[k]*w[0] + v1[k]*w[1] + v2[k]*w[2] + v3[k]*w[3]));
}
}
}
}
}
}