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Pillow/libImaging/Geometry.c
Alex Clark 9a640e3157 Forking PIL
2010-07-30 22:52:47 -04:00

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/*
* The Python Imaging Library
* $Id$
*
* the imaging geometry methods
*
* history:
* 1995-06-15 fl Created
* 1996-04-15 fl Changed origin
* 1996-05-18 fl Fixed rotate90/270 for rectangular images
* 1996-05-27 fl Added general purpose transform
* 1996-11-22 fl Don't crash when resizing from outside source image
* 1997-08-09 fl Fixed rounding error in resize
* 1998-09-21 fl Incorporated transformation patches (from Zircon #2)
* 1998-09-22 fl Added bounding box to transform engines
* 1999-02-03 fl Fixed bicubic filtering for RGB images
* 1999-02-16 fl Added fixed-point version of affine transform
* 2001-03-28 fl Fixed transform(EXTENT) for xoffset < 0
* 2003-03-10 fl Compiler tweaks
* 2004-09-19 fl Fixed bilinear/bicubic filtering of LA images
*
* Copyright (c) 1997-2003 by Secret Labs AB
* Copyright (c) 1995-1997 by Fredrik Lundh
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
/* Undef if you don't need resampling filters */
#define WITH_FILTERS
#define COORD(v) ((v) < 0.0 ? -1 : ((int)(v)))
#define FLOOR(v) ((v) < 0.0 ? ((int)floor(v)) : ((int)(v)))
/* -------------------------------------------------------------------- */
/* Transpose operations */
Imaging
ImagingFlipLeftRight(Imaging imOut, Imaging imIn)
{
ImagingSectionCookie cookie;
int x, y, xr;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
if (imIn->xsize != imOut->xsize || imIn->ysize != imOut->ysize)
return (Imaging) ImagingError_Mismatch();
ImagingCopyInfo(imOut, imIn);
#define FLIP_HORIZ(image)\
for (y = 0; y < imIn->ysize; y++) {\
xr = imIn->xsize-1;\
for (x = 0; x < imIn->xsize; x++, xr--)\
imOut->image[y][x] = imIn->image[y][xr];\
}
ImagingSectionEnter(&cookie);
if (imIn->image8)
FLIP_HORIZ(image8)
else
FLIP_HORIZ(image32)
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingFlipTopBottom(Imaging imOut, Imaging imIn)
{
ImagingSectionCookie cookie;
int y, yr;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
if (imIn->xsize != imOut->xsize || imIn->ysize != imOut->ysize)
return (Imaging) ImagingError_Mismatch();
ImagingCopyInfo(imOut, imIn);
ImagingSectionEnter(&cookie);
yr = imIn->ysize-1;
for (y = 0; y < imIn->ysize; y++, yr--)
memcpy(imOut->image[yr], imIn->image[y], imIn->linesize);
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingRotate90(Imaging imOut, Imaging imIn)
{
ImagingSectionCookie cookie;
int x, y, xr;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
if (imIn->xsize != imOut->ysize || imIn->ysize != imOut->xsize)
return (Imaging) ImagingError_Mismatch();
ImagingCopyInfo(imOut, imIn);
#define ROTATE_90(image)\
for (y = 0; y < imIn->ysize; y++) {\
xr = imIn->xsize-1;\
for (x = 0; x < imIn->xsize; x++, xr--)\
imOut->image[xr][y] = imIn->image[y][x];\
}
ImagingSectionEnter(&cookie);
if (imIn->image8)
ROTATE_90(image8)
else
ROTATE_90(image32)
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingRotate180(Imaging imOut, Imaging imIn)
{
ImagingSectionCookie cookie;
int x, y, xr, yr;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
if (imIn->xsize != imOut->xsize || imIn->ysize != imOut->ysize)
return (Imaging) ImagingError_Mismatch();
ImagingCopyInfo(imOut, imIn);
yr = imIn->ysize-1;
#define ROTATE_180(image)\
for (y = 0; y < imIn->ysize; y++, yr--) {\
xr = imIn->xsize-1;\
for (x = 0; x < imIn->xsize; x++, xr--)\
imOut->image[y][x] = imIn->image[yr][xr];\
}
ImagingSectionEnter(&cookie);
if (imIn->image8)
ROTATE_180(image8)
else
ROTATE_180(image32)
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingRotate270(Imaging imOut, Imaging imIn)
{
ImagingSectionCookie cookie;
int x, y, yr;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
if (imIn->xsize != imOut->ysize || imIn->ysize != imOut->xsize)
return (Imaging) ImagingError_Mismatch();
ImagingCopyInfo(imOut, imIn);
yr = imIn->ysize - 1;
#define ROTATE_270(image)\
for (y = 0; y < imIn->ysize; y++, yr--)\
for (x = 0; x < imIn->xsize; x++)\
imOut->image[x][y] = imIn->image[yr][x];
ImagingSectionEnter(&cookie);
if (imIn->image8)
ROTATE_270(image8)
else
ROTATE_270(image32)
ImagingSectionLeave(&cookie);
return imOut;
}
/* -------------------------------------------------------------------- */
/* Transforms */
/* transform primitives (ImagingTransformMap) */
static int
affine_transform(double* xin, double* yin, int x, int y, void* data)
{
/* full moon tonight. your compiler will generate bogus code
for simple expressions, unless you reorganize the code, or
install Service Pack 3 */
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];
xin[0] = a0 + a1*x + a2*y;
yin[0] = a3 + a4*x + a5*y;
return 1;
}
static int
perspective_transform(double* xin, double* yin, 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 + a1*x + a2*y) / (a6*x + a7*y + 1);
yin[0] = (a3 + a4*x + a5*y) / (a6*x + a7*y + 1);
return 1;
}
#if 0
static int
quadratic_transform(double* xin, double* yin, 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];
double a8 = a[8]; double a9 = a[9]; double a10 = a[10]; double a11 = a[11];
xin[0] = a0 + a1*x + a2*y + a3*x*x + a4*x*y + a5*y*y;
yin[0] = a6 + a7*x + a8*y + a9*x*x + a10*x*y + a11*y*y;
return 1;
}
#endif
static int
quad_transform(double* xin, double* yin, int x, int y, void* data)
{
/* quad warp: map quadrilateral to rectangle */
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 + a1*x + a2*y + a3*x*y;
yin[0] = a4 + a5*x + a6*y + a7*x*y;
return 1;
}
/* transform filters (ImagingTransformFilter) */
#ifdef WITH_FILTERS
static int
nearest_filter8(void* out, Imaging im, double xin, double yin, void* data)
{
int x = COORD(xin);
int y = COORD(yin);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((UINT8*)out)[0] = im->image8[y][x];
return 1;
}
static int
nearest_filter16(void* out, Imaging im, double xin, double yin, void* data)
{
int x = COORD(xin);
int y = COORD(yin);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((INT16*)out)[0] = ((INT16*)(im->image8[y]))[x];
return 1;
}
static int
nearest_filter32(void* out, Imaging im, double xin, double yin, void* data)
{
int x = COORD(xin);
int y = COORD(yin);
if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize)
return 0;
((INT32*)out)[0] = im->image32[y][x];
return 1;
}
#define XCLIP(im, x) ( ((x) < 0) ? 0 : ((x) < im->xsize) ? (x) : im->xsize-1 )
#define YCLIP(im, y) ( ((y) < 0) ? 0 : ((y) < im->ysize) ? (y) : im->ysize-1 )
#define BILINEAR(v, a, b, d)\
(v = (a) + ( (b) - (a) ) * (d))
#define BILINEAR_HEAD(type)\
int x, y;\
int x0, x1;\
double v1, v2;\
double dx, dy;\
type* in;\
if (xin < 0.0 || xin >= im->xsize || yin < 0.0 || yin >= im->ysize)\
return 0;\
xin -= 0.5;\
yin -= 0.5;\
x = FLOOR(xin);\
y = FLOOR(yin);\
dx = xin - x;\
dy = yin - y;
#define BILINEAR_BODY(type, image, step, offset) {\
in = (type*) ((image)[YCLIP(im, y)] + offset);\
x0 = XCLIP(im, x+0)*step;\
x1 = XCLIP(im, x+1)*step;\
BILINEAR(v1, in[x0], in[x1], dx);\
if (y+1 >= 0 && y+1 < im->ysize) {\
in = (type*) ((image)[y+1] + offset);\
BILINEAR(v2, in[x0], in[x1], dx);\
} else\
v2 = v1;\
BILINEAR(v1, v1, v2, dy);\
}
static int
bilinear_filter8(void* out, Imaging im, double xin, double yin, void* data)
{
BILINEAR_HEAD(UINT8);
BILINEAR_BODY(UINT8, im->image8, 1, 0);
((UINT8*)out)[0] = (UINT8) v1;
return 1;
}
static int
bilinear_filter32I(void* out, Imaging im, double xin, double yin, void* data)
{
BILINEAR_HEAD(INT32);
BILINEAR_BODY(INT32, im->image32, 1, 0);
((INT32*)out)[0] = (INT32) v1;
return 1;
}
static int
bilinear_filter32F(void* out, Imaging im, double xin, double yin, void* data)
{
BILINEAR_HEAD(FLOAT32);
BILINEAR_BODY(FLOAT32, im->image32, 1, 0);
((FLOAT32*)out)[0] = (FLOAT32) v1;
return 1;
}
static int
bilinear_filter32LA(void* out, Imaging im, double xin, double yin, void* data)
{
BILINEAR_HEAD(UINT8);
BILINEAR_BODY(UINT8, im->image, 4, 0);
((UINT8*)out)[0] = (UINT8) v1;
((UINT8*)out)[1] = (UINT8) v1;
((UINT8*)out)[2] = (UINT8) v1;
BILINEAR_BODY(UINT8, im->image, 4, 3);
((UINT8*)out)[3] = (UINT8) v1;
return 1;
}
static int
bilinear_filter32RGB(void* out, Imaging im, double xin, double yin, void* data)
{
int b;
BILINEAR_HEAD(UINT8);
for (b = 0; b < im->bands; b++) {
BILINEAR_BODY(UINT8, im->image, 4, b);
((UINT8*)out)[b] = (UINT8) v1;
}
return 1;
}
#define BICUBIC(v, v1, v2, v3, v4, d) {\
double p1 = v2;\
double p2 = -v1 + v3;\
double p3 = 2*(v1 - v2) + v3 - v4;\
double p4 = -v1 + v2 - v3 + v4;\
v = p1 + (d)*(p2 + (d)*(p3 + (d)*p4));\
}
#define BICUBIC_HEAD(type)\
int x = FLOOR(xin);\
int y = FLOOR(yin);\
int x0, x1, x2, x3;\
double v1, v2, v3, v4;\
double dx, dy;\
type* in;\
if (xin < 0.0 || xin >= im->xsize || yin < 0.0 || yin >= im->ysize)\
return 0;\
xin -= 0.5;\
yin -= 0.5;\
x = FLOOR(xin);\
y = FLOOR(yin);\
dx = xin - x;\
dy = yin - y;\
x--; y--;
#define BICUBIC_BODY(type, image, step, offset) {\
in = (type*) ((image)[YCLIP(im, y)] + offset);\
x0 = XCLIP(im, x+0)*step;\
x1 = XCLIP(im, x+1)*step;\
x2 = XCLIP(im, x+2)*step;\
x3 = XCLIP(im, x+3)*step;\
BICUBIC(v1, in[x0], in[x1], in[x2], in[x3], dx);\
if (y+1 >= 0 && y+1 < im->ysize) {\
in = (type*) ((image)[y+1] + offset);\
BICUBIC(v2, in[x0], in[x1], in[x2], in[x3], dx);\
} else\
v2 = v1;\
if (y+2 >= 0 && y+2 < im->ysize) {\
in = (type*) ((image)[y+2] + offset);\
BICUBIC(v3, in[x0], in[x1], in[x2], in[x3], dx);\
} else\
v3 = v2;\
if (y+3 >= 0 && y+3 < im->ysize) {\
in = (type*) ((image)[y+3] + offset);\
BICUBIC(v4, in[x0], in[x1], in[x2], in[x3], dx);\
} else\
v4 = v3;\
BICUBIC(v1, v1, v2, v3, v4, dy);\
}
static int
bicubic_filter8(void* out, Imaging im, double xin, double yin, void* data)
{
BICUBIC_HEAD(UINT8);
BICUBIC_BODY(UINT8, im->image8, 1, 0);
if (v1 <= 0.0)
((UINT8*)out)[0] = 0;
else if (v1 >= 255.0)
((UINT8*)out)[0] = 255;
else
((UINT8*)out)[0] = (UINT8) v1;
return 1;
}
static int
bicubic_filter32I(void* out, Imaging im, double xin, double yin, void* data)
{
BICUBIC_HEAD(INT32);
BICUBIC_BODY(INT32, im->image32, 1, 0);
((INT32*)out)[0] = (INT32) v1;
return 1;
}
static int
bicubic_filter32F(void* out, Imaging im, double xin, double yin, void* data)
{
BICUBIC_HEAD(FLOAT32);
BICUBIC_BODY(FLOAT32, im->image32, 1, 0);
((FLOAT32*)out)[0] = (FLOAT32) v1;
return 1;
}
static int
bicubic_filter32LA(void* out, Imaging im, double xin, double yin, void* data)
{
BICUBIC_HEAD(UINT8);
BICUBIC_BODY(UINT8, im->image, 4, 0);
if (v1 <= 0.0) {
((UINT8*)out)[0] = 0;
((UINT8*)out)[1] = 0;
((UINT8*)out)[2] = 0;
} else if (v1 >= 255.0) {
((UINT8*)out)[0] = 255;
((UINT8*)out)[1] = 255;
((UINT8*)out)[2] = 255;
} else {
((UINT8*)out)[0] = (UINT8) v1;
((UINT8*)out)[1] = (UINT8) v1;
((UINT8*)out)[2] = (UINT8) v1;
}
BICUBIC_BODY(UINT8, im->image, 4, 3);
if (v1 <= 0.0)
((UINT8*)out)[3] = 0;
else if (v1 >= 255.0)
((UINT8*)out)[3] = 255;
else
((UINT8*)out)[3] = (UINT8) v1;
return 1;
}
static int
bicubic_filter32RGB(void* out, Imaging im, double xin, double yin, void* data)
{
int b;
BICUBIC_HEAD(UINT8);
for (b = 0; b < im->bands; b++) {
BICUBIC_BODY(UINT8, im->image, 4, b);
if (v1 <= 0.0)
((UINT8*)out)[b] = 0;
else if (v1 >= 255.0)
((UINT8*)out)[b] = 255;
else
((UINT8*)out)[b] = (UINT8) v1;
}
return 1;
}
static ImagingTransformFilter
getfilter(Imaging im, int filterid)
{
switch (filterid) {
case IMAGING_TRANSFORM_NEAREST:
if (im->image8)
switch (im->type) {
case IMAGING_TYPE_UINT8:
return (ImagingTransformFilter) nearest_filter8;
case IMAGING_TYPE_SPECIAL:
switch (im->pixelsize) {
case 1:
return (ImagingTransformFilter) nearest_filter8;
case 2:
return (ImagingTransformFilter) nearest_filter16;
case 4:
return (ImagingTransformFilter) nearest_filter32;
}
}
else
return (ImagingTransformFilter) nearest_filter32;
break;
case IMAGING_TRANSFORM_BILINEAR:
if (im->image8)
return (ImagingTransformFilter) bilinear_filter8;
else if (im->image32) {
switch (im->type) {
case IMAGING_TYPE_UINT8:
if (im->bands == 2)
return (ImagingTransformFilter) bilinear_filter32LA;
else
return (ImagingTransformFilter) bilinear_filter32RGB;
case IMAGING_TYPE_INT32:
return (ImagingTransformFilter) bilinear_filter32I;
case IMAGING_TYPE_FLOAT32:
return (ImagingTransformFilter) bilinear_filter32F;
}
}
break;
case IMAGING_TRANSFORM_BICUBIC:
if (im->image8)
return (ImagingTransformFilter) bicubic_filter8;
else if (im->image32) {
switch (im->type) {
case IMAGING_TYPE_UINT8:
if (im->bands == 2)
return (ImagingTransformFilter) bicubic_filter32LA;
else
return (ImagingTransformFilter) bicubic_filter32RGB;
case IMAGING_TYPE_INT32:
return (ImagingTransformFilter) bicubic_filter32I;
case IMAGING_TYPE_FLOAT32:
return (ImagingTransformFilter) bicubic_filter32F;
}
}
break;
}
/* no such filter */
return NULL;
}
#else
#define getfilter(im, id) NULL
#endif
/* transformation engines */
Imaging
ImagingTransform(
Imaging imOut, Imaging imIn, int x0, int y0, int x1, int y1,
ImagingTransformMap transform, void* transform_data,
ImagingTransformFilter filter, void* filter_data,
int fill)
{
/* slow generic transformation. use ImagingTransformAffine or
ImagingScaleAffine where possible. */
ImagingSectionCookie cookie;
int x, y;
char *out;
double xx, yy;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
ImagingCopyInfo(imOut, imIn);
ImagingSectionEnter(&cookie);
if (x0 < 0)
x0 = 0;
if (y0 < 0)
y0 = 0;
if (x1 > imOut->xsize)
x1 = imOut->xsize;
if (y1 > imOut->ysize)
y1 = imOut->ysize;
for (y = y0; y < y1; y++) {
out = imOut->image[y] + x0*imOut->pixelsize;
for (x = x0; x < x1; x++) {
if (!transform(&xx, &yy, x-x0, y-y0, transform_data) ||
!filter(out, imIn, xx, yy, filter_data)) {
if (fill)
memset(out, 0, imOut->pixelsize);
}
out += imOut->pixelsize;
}
}
ImagingSectionLeave(&cookie);
return imOut;
}
static Imaging
ImagingScaleAffine(Imaging imOut, Imaging imIn,
int x0, int y0, int x1, int y1,
double a[6], int fill)
{
/* scale, nearest neighbour resampling */
ImagingSectionCookie cookie;
int x, y;
int xin;
double xo, yo;
int xmin, xmax;
int *xintab;
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
ImagingCopyInfo(imOut, imIn);
if (x0 < 0)
x0 = 0;
if (y0 < 0)
y0 = 0;
if (x1 > imOut->xsize)
x1 = imOut->xsize;
if (y1 > imOut->ysize)
y1 = imOut->ysize;
xintab = (int*) malloc(imOut->xsize * sizeof(int));
if (!xintab) {
ImagingDelete(imOut);
return (Imaging) ImagingError_MemoryError();
}
xo = a[0];
yo = a[3];
xmin = x1;
xmax = x0;
/* Pretabulate horizontal pixel positions */
for (x = x0; x < x1; x++) {
xin = COORD(xo);
if (xin >= 0 && xin < (int) imIn->xsize) {
xmax = x+1;
if (x < xmin)
xmin = x;
xintab[x] = xin;
}
xo += a[1];
}
#define AFFINE_SCALE(pixel, image)\
for (y = y0; y < y1; y++) {\
int yi = COORD(yo);\
pixel *in, *out;\
out = imOut->image[y];\
if (fill && x1 > x0)\
memset(out+x0, 0, (x1-x0)*sizeof(pixel));\
if (yi >= 0 && yi < imIn->ysize) {\
in = imIn->image[yi];\
for (x = xmin; x < xmax; x++)\
out[x] = in[xintab[x]];\
}\
yo += a[5];\
}
ImagingSectionEnter(&cookie);
if (imIn->image8) {
AFFINE_SCALE(UINT8, image8);
} else {
AFFINE_SCALE(INT32, image32);
}
ImagingSectionLeave(&cookie);
free(xintab);
return imOut;
}
static inline int
check_fixed(double a[6], int x, int y)
{
return (fabs(a[0] + x*a[1] + y*a[2]) < 32768.0 &&
fabs(a[3] + x*a[4] + y*a[5]) < 32768.0);
}
static inline Imaging
affine_fixed(Imaging imOut, Imaging imIn,
int x0, int y0, int x1, int y1,
double a[6], int filterid, int fill)
{
/* affine transform, nearest neighbour resampling, fixed point
arithmetics */
int x, y;
int xin, yin;
int xsize, ysize;
int xx, yy;
int a0, a1, a2, a3, a4, a5;
ImagingCopyInfo(imOut, imIn);
xsize = (int) imIn->xsize;
ysize = (int) imIn->ysize;
/* 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]);
#define AFFINE_TRANSFORM_FIXED(pixel, image)\
for (y = y0; y < y1; y++) {\
pixel *out;\
xx = a0;\
yy = a3;\
out = imOut->image[y];\
if (fill && x1 > x0)\
memset(out+x0, 0, (x1-x0)*sizeof(pixel));\
for (x = x0; x < x1; x++, out++) {\
xin = xx >> 16;\
if (xin >= 0 && xin < xsize) {\
yin = yy >> 16;\
if (yin >= 0 && yin < ysize)\
*out = imIn->image[yin][xin];\
}\
xx += a1;\
yy += a4;\
}\
a0 += a2;\
a3 += a5;\
}
if (imIn->image8)
AFFINE_TRANSFORM_FIXED(UINT8, image8)
else
AFFINE_TRANSFORM_FIXED(INT32, image32)
return imOut;
}
Imaging
ImagingTransformAffine(Imaging imOut, Imaging imIn,
int x0, int y0, int x1, int y1,
double a[6], int filterid, int fill)
{
/* affine transform, nearest neighbour resampling, floating point
arithmetics*/
ImagingSectionCookie cookie;
int x, y;
int xin, yin;
int xsize, ysize;
double xx, yy;
double xo, yo;
if (filterid || imIn->type == IMAGING_TYPE_SPECIAL) {
/* Filtered transform */
ImagingTransformFilter filter = getfilter(imIn, filterid);
if (!filter)
return (Imaging) ImagingError_ValueError("unknown filter");
return ImagingTransform(
imOut, imIn,
x0, y0, x1, y1,
affine_transform, a,
filter, NULL, fill);
}
if (a[2] == 0 && a[4] == 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();
if (x0 < 0)
x0 = 0;
if (y0 < 0)
y0 = 0;
if (x1 > imOut->xsize)
x1 = imOut->xsize;
if (y1 > imOut->ysize)
y1 = imOut->ysize;
ImagingCopyInfo(imOut, imIn);
/* translate all four corners to check if they are within the
range that can be represented by the fixed point arithmetics */
if (check_fixed(a, 0, 0) && check_fixed(a, x1-x0, y1-y0) &&
check_fixed(a, 0, y1-y0) && check_fixed(a, x1-x0, 0))
return affine_fixed(imOut, imIn, x0, y0, x1, y1, a, filterid, fill);
/* FIXME: cannot really think of any reasonable case when the
following code is used. maybe we should fall back on the slow
generic transform engine in this case? */
xsize = (int) imIn->xsize;
ysize = (int) imIn->ysize;
xo = a[0];
yo = a[3];
#define AFFINE_TRANSFORM(pixel, image)\
for (y = y0; y < y1; y++) {\
pixel *out;\
xx = xo;\
yy = yo;\
out = imOut->image[y];\
if (fill && x1 > x0)\
memset(out+x0, 0, (x1-x0)*sizeof(pixel));\
for (x = x0; x < x1; x++, out++) {\
xin = COORD(xx);\
if (xin >= 0 && xin < xsize) {\
yin = COORD(yy);\
if (yin >= 0 && yin < ysize)\
*out = imIn->image[yin][xin];\
}\
xx += a[1];\
yy += a[4];\
}\
xo += a[2];\
yo += a[5];\
}
ImagingSectionEnter(&cookie);
if (imIn->image8)
AFFINE_TRANSFORM(UINT8, image8)
else
AFFINE_TRANSFORM(INT32, image32)
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingTransformPerspective(Imaging imOut, Imaging imIn,
int x0, int y0, int x1, int y1,
double a[8], int filterid, int fill)
{
ImagingTransformFilter filter = getfilter(imIn, filterid);
if (!filter)
return (Imaging) ImagingError_ValueError("bad filter number");
return ImagingTransform(
imOut, imIn,
x0, y0, x1, y1,
perspective_transform, a,
filter, NULL,
fill);
}
Imaging
ImagingTransformQuad(Imaging imOut, Imaging imIn,
int x0, int y0, int x1, int y1,
double a[8], int filterid, int fill)
{
ImagingTransformFilter filter = getfilter(imIn, filterid);
if (!filter)
return (Imaging) ImagingError_ValueError("bad filter number");
return ImagingTransform(
imOut, imIn,
x0, y0, x1, y1,
quad_transform, a,
filter, NULL,
fill);
}
/* -------------------------------------------------------------------- */
/* Convenience functions */
Imaging
ImagingResize(Imaging imOut, Imaging imIn, int filterid)
{
double a[6];
if (imOut->xsize == imIn->xsize && imOut->ysize == imIn->ysize)
return ImagingCopy2(imOut, imIn);
memset(a, 0, sizeof a);
a[1] = (double) imIn->xsize / imOut->xsize;
a[5] = (double) imIn->ysize / imOut->ysize;
if (!filterid && imIn->type != IMAGING_TYPE_SPECIAL)
return ImagingScaleAffine(
imOut, imIn,
0, 0, imOut->xsize, imOut->ysize,
a, 1);
return ImagingTransformAffine(
imOut, imIn,
0, 0, imOut->xsize, imOut->ysize,
a, filterid, 1);
}
Imaging
ImagingRotate(Imaging imOut, Imaging imIn, double theta, int filterid)
{
int xsize, ysize;
double sintheta, costheta;
double a[6];
/* Setup an affine transform to rotate around the image center */
theta = -theta * M_PI / 180.0;
sintheta = sin(theta);
costheta = cos(theta);
xsize = imOut->xsize;
ysize = imOut->ysize;
a[0] = -costheta * xsize/2 - sintheta * ysize/2 + xsize/2;
a[1] = costheta;
a[2] = sintheta;
a[3] = sintheta * xsize/2 - costheta * ysize/2 + ysize/2;
a[4] = -sintheta;
a[5] = costheta;
return ImagingTransformAffine(
imOut, imIn,
0, 0, imOut->xsize, imOut->ysize,
a, filterid, 1);
}
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