Pillow/libImaging/Filter.c

348 lines
13 KiB
C

/*
* The Python Imaging Library
* $Id$
*
* apply convolution kernel to image
*
* history:
* 1995-11-26 fl Created, supports 3x3 kernels
* 1995-11-27 fl Added 5x5 kernels, copy border
* 1999-07-26 fl Eliminated a few compiler warnings
* 2002-06-09 fl Moved kernel definitions to Python
* 2002-06-11 fl Support floating point kernels
* 2003-09-15 fl Added ImagingExpand helper
*
* Copyright (c) Secret Labs AB 1997-2002. All rights reserved.
* Copyright (c) Fredrik Lundh 1995.
*
* See the README file for information on usage and redistribution.
*/
/*
* FIXME: Support RGB and RGBA/CMYK modes as well
* FIXME: Expand image border (current version leaves border as is)
* FIXME: Implement image processing gradient filters
*/
#include "Imaging.h"
static inline UINT8 clip8(float in)
{
if (in <= 0.0)
return 0;
if (in >= 255.0)
return 255;
return (UINT8) in;
}
Imaging
ImagingExpand(Imaging imIn, int xmargin, int ymargin, int mode)
{
Imaging imOut;
int x, y;
ImagingSectionCookie cookie;
if (xmargin < 0 && ymargin < 0)
return (Imaging) ImagingError_ValueError("bad kernel size");
imOut = ImagingNewDirty(
imIn->mode, imIn->xsize+2*xmargin, imIn->ysize+2*ymargin);
if (!imOut)
return NULL;
#define EXPAND_LINE(type, image, yin, yout) {\
for (x = 0; x < xmargin; x++)\
imOut->image[yout][x] = imIn->image[yin][0];\
for (x = 0; x < imIn->xsize; x++)\
imOut->image[yout][x+xmargin] = imIn->image[yin][x];\
for (x = 0; x < xmargin; x++)\
imOut->image[yout][xmargin+imIn->xsize+x] =\
imIn->image[yin][imIn->xsize-1];\
}
#define EXPAND(type, image) {\
for (y = 0; y < ymargin; y++)\
EXPAND_LINE(type, image, 0, y);\
for (y = 0; y < imIn->ysize; y++)\
EXPAND_LINE(type, image, y, y+ymargin);\
for (y = 0; y < ymargin; y++)\
EXPAND_LINE(type, image, imIn->ysize-1, ymargin+imIn->ysize+y);\
}
ImagingSectionEnter(&cookie);
if (imIn->image8) {
EXPAND(UINT8, image8);
} else {
EXPAND(INT32, image32);
}
ImagingSectionLeave(&cookie);
ImagingCopyPalette(imOut, imIn);
return imOut;
}
void
ImagingFilter3x3(Imaging imOut, Imaging im, const float* kernel,
float offset)
{
#define KERNEL1x3(in0, x, kernel, d) ( \
_i2f((UINT8) in0[x-d]) * (kernel)[0] + \
_i2f((UINT8) in0[x]) * (kernel)[1] + \
_i2f((UINT8) in0[x+d]) * (kernel)[2])
int x = 0, y = 0;
memcpy(imOut->image[0], im->image[0], im->linesize);
if (im->bands == 1) {
// Add one time for rounding
offset += 0.5;
for (y = 1; y < im->ysize-1; y++) {
UINT8* in_1 = (UINT8*) im->image[y-1];
UINT8* in0 = (UINT8*) im->image[y];
UINT8* in1 = (UINT8*) im->image[y+1];
UINT8* out = (UINT8*) imOut->image[y];
out[0] = in0[0];
for (x = 1; x < im->xsize-1; x++) {
float ss = offset;
ss += KERNEL1x3(in1, x, &kernel[0], 1);
ss += KERNEL1x3(in0, x, &kernel[3], 1);
ss += KERNEL1x3(in_1, x, &kernel[6], 1);
out[x] = clip8(ss);
}
out[x] = in0[x];
}
} else {
// Add one time for rounding
offset += 0.5;
for (y = 1; y < im->ysize-1; y++) {
UINT8* in_1 = (UINT8*) im->image[y-1];
UINT8* in0 = (UINT8*) im->image[y];
UINT8* in1 = (UINT8*) im->image[y+1];
UINT32* out = (UINT32*) imOut->image[y];
out[0] = ((UINT32*) in0)[0];
if (im->bands == 2) {
for (x = 1; x < im->xsize-1; x++) {
float ss0 = offset;
float ss3 = offset;
ss0 += KERNEL1x3(in1, x*4+0, &kernel[0], 4);
ss3 += KERNEL1x3(in1, x*4+3, &kernel[0], 4);
ss0 += KERNEL1x3(in0, x*4+0, &kernel[3], 4);
ss3 += KERNEL1x3(in0, x*4+3, &kernel[3], 4);
ss0 += KERNEL1x3(in_1, x*4+0, &kernel[6], 4);
ss3 += KERNEL1x3(in_1, x*4+3, &kernel[6], 4);
out[x] = MAKE_UINT32(clip8(ss0), 0, 0, clip8(ss3));
}
} else if (im->bands == 3) {
for (x = 1; x < im->xsize-1; x++) {
float ss0 = offset;
float ss1 = offset;
float ss2 = offset;
ss0 += KERNEL1x3(in1, x*4+0, &kernel[0], 4);
ss1 += KERNEL1x3(in1, x*4+1, &kernel[0], 4);
ss2 += KERNEL1x3(in1, x*4+2, &kernel[0], 4);
ss0 += KERNEL1x3(in0, x*4+0, &kernel[3], 4);
ss1 += KERNEL1x3(in0, x*4+1, &kernel[3], 4);
ss2 += KERNEL1x3(in0, x*4+2, &kernel[3], 4);
ss0 += KERNEL1x3(in_1, x*4+0, &kernel[6], 4);
ss1 += KERNEL1x3(in_1, x*4+1, &kernel[6], 4);
ss2 += KERNEL1x3(in_1, x*4+2, &kernel[6], 4);
out[x] = MAKE_UINT32(
clip8(ss0), clip8(ss1), clip8(ss2), 0);
}
} else if (im->bands == 4) {
for (x = 1; x < im->xsize-1; x++) {
float ss0 = offset;
float ss1 = offset;
float ss2 = offset;
float ss3 = offset;
ss0 += KERNEL1x3(in1, x*4+0, &kernel[0], 4);
ss1 += KERNEL1x3(in1, x*4+1, &kernel[0], 4);
ss2 += KERNEL1x3(in1, x*4+2, &kernel[0], 4);
ss3 += KERNEL1x3(in1, x*4+3, &kernel[0], 4);
ss0 += KERNEL1x3(in0, x*4+0, &kernel[3], 4);
ss1 += KERNEL1x3(in0, x*4+1, &kernel[3], 4);
ss2 += KERNEL1x3(in0, x*4+2, &kernel[3], 4);
ss3 += KERNEL1x3(in0, x*4+3, &kernel[3], 4);
ss0 += KERNEL1x3(in_1, x*4+0, &kernel[6], 4);
ss1 += KERNEL1x3(in_1, x*4+1, &kernel[6], 4);
ss2 += KERNEL1x3(in_1, x*4+2, &kernel[6], 4);
ss3 += KERNEL1x3(in_1, x*4+3, &kernel[6], 4);
out[x] = MAKE_UINT32(
clip8(ss0), clip8(ss1), clip8(ss2), clip8(ss3));
}
}
out[x] = ((UINT32*) in0)[x];
}
}
memcpy(imOut->image[y], im->image[y], im->linesize);
}
void
ImagingFilter5x5(Imaging imOut, Imaging im, const float* kernel,
float offset)
{
#define KERNEL1x5(in0, x, kernel, d) ( \
_i2f((UINT8) in0[x-d-d]) * (kernel)[0] + \
_i2f((UINT8) in0[x-d]) * (kernel)[1] + \
_i2f((UINT8) in0[x]) * (kernel)[2] + \
_i2f((UINT8) in0[x+d]) * (kernel)[3] + \
_i2f((UINT8) in0[x+d+d]) * (kernel)[4])
int x = 0, y = 0;
memcpy(imOut->image[0], im->image[0], im->linesize);
memcpy(imOut->image[1], im->image[1], im->linesize);
if (im->bands == 1) {
// Add one time for rounding
offset += 0.5;
for (y = 2; y < im->ysize-2; y++) {
UINT8* in_2 = (UINT8*) im->image[y-2];
UINT8* in_1 = (UINT8*) im->image[y-1];
UINT8* in0 = (UINT8*) im->image[y];
UINT8* in1 = (UINT8*) im->image[y+1];
UINT8* in2 = (UINT8*) im->image[y+2];
UINT8* out = (UINT8*) imOut->image[y];
out[0] = in0[0];
out[1] = in0[1];
for (x = 2; x < im->xsize-2; x++) {
float ss = offset;
ss += KERNEL1x5(in2, x, &kernel[0], 1);
ss += KERNEL1x5(in1, x, &kernel[5], 1);
ss += KERNEL1x5(in0, x, &kernel[10], 1);
ss += KERNEL1x5(in_1, x, &kernel[15], 1);
ss += KERNEL1x5(in_2, x, &kernel[20], 1);
out[x] = clip8(ss);
}
out[x+0] = in0[x+0];
out[x+1] = in0[x+1];
}
} else {
// Add one time for rounding
offset += 0.5;
for (y = 2; y < im->ysize-2; y++) {
UINT8* in_2 = (UINT8*) im->image[y-2];
UINT8* in_1 = (UINT8*) im->image[y-1];
UINT8* in0 = (UINT8*) im->image[y];
UINT8* in1 = (UINT8*) im->image[y+1];
UINT8* in2 = (UINT8*) im->image[y+2];
UINT32* out = (UINT32*) imOut->image[y];
out[0] = ((UINT32*) in0)[0];
out[1] = ((UINT32*) in0)[1];
if (im->bands == 2) {
for (x = 2; x < im->xsize-2; x++) {
float ss0 = offset;
float ss3 = offset;
ss0 += KERNEL1x5(in2, x*4+0, &kernel[0], 4);
ss3 += KERNEL1x5(in2, x*4+3, &kernel[0], 4);
ss0 += KERNEL1x5(in1, x*4+0, &kernel[5], 4);
ss3 += KERNEL1x5(in1, x*4+3, &kernel[5], 4);
ss0 += KERNEL1x5(in0, x*4+0, &kernel[10], 4);
ss3 += KERNEL1x5(in0, x*4+3, &kernel[10], 4);
ss0 += KERNEL1x5(in_1, x*4+0, &kernel[15], 4);
ss3 += KERNEL1x5(in_1, x*4+3, &kernel[15], 4);
ss0 += KERNEL1x5(in_2, x*4+0, &kernel[20], 4);
ss3 += KERNEL1x5(in_2, x*4+3, &kernel[20], 4);
out[x] = MAKE_UINT32(clip8(ss0), 0, 0, clip8(ss3));
}
} else if (im->bands == 3) {
for (x = 2; x < im->xsize-2; x++) {
float ss0 = offset;
float ss1 = offset;
float ss2 = offset;
ss0 += KERNEL1x5(in2, x*4+0, &kernel[0], 4);
ss1 += KERNEL1x5(in2, x*4+1, &kernel[0], 4);
ss2 += KERNEL1x5(in2, x*4+2, &kernel[0], 4);
ss0 += KERNEL1x5(in1, x*4+0, &kernel[5], 4);
ss1 += KERNEL1x5(in1, x*4+1, &kernel[5], 4);
ss2 += KERNEL1x5(in1, x*4+2, &kernel[5], 4);
ss0 += KERNEL1x5(in0, x*4+0, &kernel[10], 4);
ss1 += KERNEL1x5(in0, x*4+1, &kernel[10], 4);
ss2 += KERNEL1x5(in0, x*4+2, &kernel[10], 4);
ss0 += KERNEL1x5(in_1, x*4+0, &kernel[15], 4);
ss1 += KERNEL1x5(in_1, x*4+1, &kernel[15], 4);
ss2 += KERNEL1x5(in_1, x*4+2, &kernel[15], 4);
ss0 += KERNEL1x5(in_2, x*4+0, &kernel[20], 4);
ss1 += KERNEL1x5(in_2, x*4+1, &kernel[20], 4);
ss2 += KERNEL1x5(in_2, x*4+2, &kernel[20], 4);
out[x] = MAKE_UINT32(
clip8(ss0), clip8(ss1), clip8(ss2), 0);
}
} else if (im->bands == 4) {
for (x = 2; x < im->xsize-2; x++) {
float ss0 = offset;
float ss1 = offset;
float ss2 = offset;
float ss3 = offset;
ss0 += KERNEL1x5(in2, x*4+0, &kernel[0], 4);
ss1 += KERNEL1x5(in2, x*4+1, &kernel[0], 4);
ss2 += KERNEL1x5(in2, x*4+2, &kernel[0], 4);
ss3 += KERNEL1x5(in2, x*4+3, &kernel[0], 4);
ss0 += KERNEL1x5(in1, x*4+0, &kernel[5], 4);
ss1 += KERNEL1x5(in1, x*4+1, &kernel[5], 4);
ss2 += KERNEL1x5(in1, x*4+2, &kernel[5], 4);
ss3 += KERNEL1x5(in1, x*4+3, &kernel[5], 4);
ss0 += KERNEL1x5(in0, x*4+0, &kernel[10], 4);
ss1 += KERNEL1x5(in0, x*4+1, &kernel[10], 4);
ss2 += KERNEL1x5(in0, x*4+2, &kernel[10], 4);
ss3 += KERNEL1x5(in0, x*4+3, &kernel[10], 4);
ss0 += KERNEL1x5(in_1, x*4+0, &kernel[15], 4);
ss1 += KERNEL1x5(in_1, x*4+1, &kernel[15], 4);
ss2 += KERNEL1x5(in_1, x*4+2, &kernel[15], 4);
ss3 += KERNEL1x5(in_1, x*4+3, &kernel[15], 4);
ss0 += KERNEL1x5(in_2, x*4+0, &kernel[20], 4);
ss1 += KERNEL1x5(in_2, x*4+1, &kernel[20], 4);
ss2 += KERNEL1x5(in_2, x*4+2, &kernel[20], 4);
ss3 += KERNEL1x5(in_2, x*4+3, &kernel[20], 4);
out[x] = MAKE_UINT32(
clip8(ss0), clip8(ss1), clip8(ss2), clip8(ss3));
}
}
out[x] = ((UINT32*) in0)[x];
out[x+1] = ((UINT32*) in0)[x+1];
}
}
memcpy(imOut->image[y], im->image[y], im->linesize);
memcpy(imOut->image[y+1], im->image[y+1], im->linesize);
}
Imaging
ImagingFilter(Imaging im, int xsize, int ysize, const FLOAT32* kernel,
FLOAT32 offset)
{
Imaging imOut;
ImagingSectionCookie cookie;
if ( ! im || im->type != IMAGING_TYPE_UINT8)
return (Imaging) ImagingError_ModeError();
if (im->xsize < xsize || im->ysize < ysize)
return ImagingCopy(im);
if ((xsize != 3 && xsize != 5) || xsize != ysize)
return (Imaging) ImagingError_ValueError("bad kernel size");
imOut = ImagingNewDirty(im->mode, im->xsize, im->ysize);
if (!imOut)
return NULL;
ImagingSectionEnter(&cookie);
if (xsize == 3) {
/* 3x3 kernel. */
ImagingFilter3x3(imOut, im, kernel, offset);
} else {
/* 5x5 kernel. */
ImagingFilter5x5(imOut, im, kernel, offset);
}
ImagingSectionLeave(&cookie);
return imOut;
}