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fix errors with pixel center coordinates

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This commit is contained in:
homm 2016-06-23 14:24:31 +03:00
parent 5ece454d1f
commit 5232361718
1 changed files with 34 additions and 22 deletions
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56
libImaging/Geometry.c
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@ -240,7 +240,7 @@ ImagingRotate270(Imaging imOut, Imaging imIn)
/* transform primitives (ImagingTransformMap) */
static int
affine_transform(double* xin, double* yin, int x, int y, void* data)
affine_transform(double* xout, double* yout, int x, int y, void* data)
{
/* full moon tonight. your compiler will generate bogus code
for simple expressions, unless you reorganize the code, or
@ -250,28 +250,34 @@ affine_transform(double* xin, double* yin, int x, int y, void* data)
double a0 = a[0]; double a1 = a[1]; double a2 = a[2];
double a3 = a[3]; double a4 = a[4]; double a5 = a[5];
xin[0] = a0*x + a1*y + a2;
yin[0] = a3*x + a4*y + a5;
double xin = x + 0.5;
double yin = y + 0.5;
xout[0] = a0*xin + a1*yin + a2;
yout[0] = a3*xin + a4*yin + a5;
return 1;
}
static int
perspective_transform(double* xin, double* yin, int x, int y, void* data)
perspective_transform(double* xout, double* yout, int x, int y, void* data)
{
double* a = (double*) data;
double a0 = a[0]; double a1 = a[1]; double a2 = a[2];
double a3 = a[3]; double a4 = a[4]; double a5 = a[5];
double a6 = a[6]; double a7 = a[7];
xin[0] = (a0*x + a1*y + a2) / (a6*x + a7*y + 1);
yin[0] = (a3*x + a4*y + a5) / (a6*x + a7*y + 1);
double xin = x + 0.5;
double yin = y + 0.5;
xout[0] = (a0*xin + a1*yin + a2) / (a6*xin + a7*yin + 1);
yout[0] = (a3*xin + a4*yin + a5) / (a6*xin + a7*yin + 1);
return 1;
}
static int
quad_transform(double* xin, double* yin, int x, int y, void* data)
quad_transform(double* xout, double* yout, int x, int y, void* data)
{
/* quad warp: map quadrilateral to rectangle */
@ -279,8 +285,11 @@ quad_transform(double* xin, double* yin, int x, int y, void* data)
double a0 = a[0]; double a1 = a[1]; double a2 = a[2]; double a3 = a[3];
double a4 = a[4]; double a5 = a[5]; double a6 = a[6]; double a7 = a[7];
xin[0] = a0 + a1*x + a2*y + a3*x*y;
yin[0] = a4 + a5*x + a6*y + a7*x*y;
double xin = x + 0.5;
double yin = y + 0.5;
xout[0] = a0 + a1*xin + a2*yin + a3*xin*yin;
yout[0] = a4 + a5*xin + a6*yin + a7*xin*yin;
return 1;
}
@ -290,8 +299,8 @@ quad_transform(double* xin, double* yin, int x, int y, void* data)
static int
nearest_filter8(void* out, Imaging im, double xin, double yin)
{
int x = COORD(xin);
int y = COORD(yin);
int x = COORD(xin + 0.5);
int y = COORD(yin + 0.5);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((UINT8*)out)[0] = im->image8[y][x];
@ -301,8 +310,8 @@ nearest_filter8(void* out, Imaging im, double xin, double yin)
static int
nearest_filter16(void* out, Imaging im, double xin, double yin)
{
int x = COORD(xin);
int y = COORD(yin);
int x = COORD(xin + 0.5);
int y = COORD(yin + 0.5);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((INT16*)out)[0] = ((INT16*)(im->image8[y]))[x];
@ -312,8 +321,8 @@ nearest_filter16(void* out, Imaging im, double xin, double yin)
static int
nearest_filter32(void* out, Imaging im, double xin, double yin)
{
int x = COORD(xin);
int y = COORD(yin);
int x = COORD(xin + 0.5);
int y = COORD(yin + 0.5);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((INT32*)out)[0] = im->image32[y][x];
@ -691,8 +700,8 @@ ImagingScaleAffine(Imaging imOut, Imaging imIn,
return (Imaging) ImagingError_MemoryError();
}
xo = a[2];
yo = a[5];
xo = a[2] + a[0] * 0.5;
yo = a[5] + a[4] * 0.5;
xmin = x1;
xmax = x0;
@ -771,8 +780,10 @@ affine_fixed(Imaging imOut, Imaging imIn,
/* use 16.16 fixed point arithmetics */
#define FIX(v) FLOOR((v)*65536.0 + 0.5)
a0 = FIX(a[0]); a1 = FIX(a[1]); a2 = FIX(a[2]);
a3 = FIX(a[3]); a4 = FIX(a[4]); a5 = FIX(a[5]);
a0 = FIX(a[0]); a1 = FIX(a[1]);
a3 = FIX(a[3]); a4 = FIX(a[4]);
a2 = FIX(a[2] + a[0] * 0.5 + a[1] * 0.5);
a5 = FIX(a[5] + a[3] * 0.5 + a[4] * 0.5);
#undef FIX
@ -835,9 +846,10 @@ ImagingTransformAffine(Imaging imOut, Imaging imIn,
filterid, fill);
}
if (a[1] == 0 && a[3] == 0)
if (a[1] == 0 && a[3] == 0) {
/* Scaling */
return ImagingScaleAffine(imOut, imIn, x0, y0, x1, y1, a, fill);
}
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
@ -867,8 +879,8 @@ ImagingTransformAffine(Imaging imOut, Imaging imIn,
xsize = (int) imIn->xsize;
ysize = (int) imIn->ysize;
xo = a[2];
yo = a[5];
xo = a[2] + a[1] * 0.5 + a[0] * 0.5;
yo = a[5] + a[4] * 0.5 + a[3] * 0.5;
#define AFFINE_TRANSFORM(pixel, image)\
for (y = y0; y < y1; y++) {\