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

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/*
* The Python Imaging Library
* $Id$
*
* convert images
*
* history:
* 1995-06-15 fl created
* 1995-11-28 fl added some "RGBA" and "CMYK" conversions
* 1996-04-22 fl added "1" conversions (same as "L")
* 1996-05-05 fl added palette conversions (hack)
* 1996-07-23 fl fixed "1" conversions to zero/non-zero convention
* 1996-11-01 fl fixed "P" to "L" and "RGB" to "1" conversions
* 1996-12-29 fl set alpha byte in RGB converters
* 1997-05-12 fl added ImagingConvert2
* 1997-05-30 fl added floating point support
* 1997-08-27 fl added "P" to "1" and "P" to "F" conversions
* 1998-01-11 fl added integer support
* 1998-07-01 fl added "YCbCr" support
* 1998-07-02 fl added "RGBX" conversions (sort of)
* 1998-07-04 fl added floyd-steinberg dithering
* 1998-07-12 fl changed "YCrCb" to "YCbCr" (!)
* 1998-12-29 fl added basic "I;16" and "I;16B" conversions
* 1999-02-03 fl added "RGBa", and "BGR" conversions (experimental)
* 2003-09-26 fl added "LA" and "PA" conversions (experimental)
* 2005-05-05 fl fixed "P" to "1" threshold
* 2005-12-08 fl fixed palette memory leak in topalette
*
* Copyright (c) 1997-2005 by Secret Labs AB.
* Copyright (c) 1995-1997 by Fredrik Lundh.
*
* See the README file for details on usage and redistribution.
*/
#include "Imaging.h"
#define CLIP(v) ((v) <= 0 ? 0 : (v) >= 255 ? 255 : (v))
#define CLIP16(v) ((v) <= -32768 ? -32768 : (v) >= 32767 ? 32767 : (v))
/* like (a * b + 127) / 255), but much faster on most platforms */
#define MULDIV255(a, b, tmp)\
(tmp = (a) * (b) + 128, ((((tmp) >> 8) + (tmp)) >> 8))
/* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
#define L(rgb)\
((INT32) (rgb)[0]*299 + (INT32) (rgb)[1]*587 + (INT32) (rgb)[2]*114)
/* ------------------- */
/* 1 (bit) conversions */
/* ------------------- */
static void
bit2l(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++)
*out++ = (*in++ != 0) ? 255 : 0;
}
static void
bit2rgb(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
UINT8 v = (*in++ != 0) ? 255 : 0;
*out++ = v;
*out++ = v;
*out++ = v;
*out++ = 255;
}
}
static void
bit2cmyk(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = 0;
*out++ = 0;
*out++ = 0;
*out++ = (*in++ != 0) ? 0 : 255;
}
}
static void
bit2ycbcr(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = (*in++ != 0) ? 255 : 0;
*out++ = 128;
*out++ = 128;
*out++ = 255;
}
}
/* ----------------- */
/* RGB/L conversions */
/* ----------------- */
static void
l2bit(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++)
*out++ = (*in++ >= 128) ? 255 : 0;
}
static void
l2la(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
UINT8 v = *in++;
*out++ = v;
*out++ = v;
*out++ = v;
*out++ = 255;
}
}
static void
l2rgb(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
UINT8 v = *in++;
*out++ = v;
*out++ = v;
*out++ = v;
*out++ = 255;
}
}
static void
la2l(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4)
*out++ = in[0];
}
static void
la2rgb(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4) {
UINT8 v = in[0];
*out++ = v;
*out++ = v;
*out++ = v;
*out++ = in[3];
}
}
static void
rgb2bit(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4)
/* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
*out++ = (L(in) >= 128000) ? 255 : 0;
}
static void
rgb2l(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4)
/* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
*out++ = L(in) / 1000;
}
static void
rgb2la(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4, out += 4) {
/* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
out[0] = out[1] = out[2] = L(in) / 1000;
out[3] = 255;
}
}
static void
rgb2i(UINT8* out_, const UINT8* in, int xsize)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++, in += 4)
*out++ = L(in) / 1000;
}
static void
rgb2f(UINT8* out_, const UINT8* in, int xsize)
{
int x;
FLOAT32* out = (FLOAT32*) out_;
for (x = 0; x < xsize; x++, in += 4)
*out++ = (float) L(in) / 1000.0F;
}
static void
rgb2bgr15(UINT8* out_, const UINT8* in, int xsize)
{
int x;
UINT16* out = (UINT16*) out_;
for (x = 0; x < xsize; x++, in += 4)
*out++ =
((((UINT16)in[0])<<7)&0x7c00) +
((((UINT16)in[1])<<2)&0x03e0) +
((((UINT16)in[2])>>3)&0x001f);
}
static void
rgb2bgr16(UINT8* out_, const UINT8* in, int xsize)
{
int x;
UINT16* out = (UINT16*) out_;
for (x = 0; x < xsize; x++, in += 4)
*out++ =
((((UINT16)in[0])<<8)&0xf800) +
((((UINT16)in[1])<<3)&0x07e0) +
((((UINT16)in[2])>>3)&0x001f);
}
static void
rgb2bgr24(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4) {
*out++ = in[2];
*out++ = in[1];
*out++ = in[0];
}
}
/* ---------------- */
/* RGBA conversions */
/* ---------------- */
static void
rgb2rgba(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = *in++;
*out++ = *in++;
*out++ = *in++;
*out++ = 255; in++;
}
}
static void
rgba2la(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4, out += 4) {
/* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
out[0] = out[1] = out[2] = L(in) / 1000;
out[3] = in[3];
}
}
static void
rgba2rgb(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = *in++;
*out++ = *in++;
*out++ = *in++;
*out++ = 255; in++;
}
}
static void
rgba2rgba(UINT8* out, const UINT8* in, int xsize)
{
int x;
unsigned int alpha, tmp;
for (x = 0; x < xsize; x++) {
alpha = in[3];
*out++ = MULDIV255(*in++, alpha, tmp);
*out++ = MULDIV255(*in++, alpha, tmp);
*out++ = MULDIV255(*in++, alpha, tmp);
*out++ = *in++;
}
}
/* ---------------- */
/* CMYK conversions */
/* ---------------- */
static void
l2cmyk(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = 0;
*out++ = 0;
*out++ = 0;
*out++ = ~(*in++);
}
}
static void
rgb2cmyk(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
/* Note: no undercolour removal */
*out++ = ~(*in++);
*out++ = ~(*in++);
*out++ = ~(*in++);
*out++ = 0; in++;
}
}
static void
cmyk2rgb(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4) {
*out++ = CLIP(255 - (in[0] + in[3]));
*out++ = CLIP(255 - (in[1] + in[3]));
*out++ = CLIP(255 - (in[2] + in[3]));
*out++ = 255;
}
}
/* ------------- */
/* I conversions */
/* ------------- */
static void
bit2i(UINT8* out_, const UINT8* in, int xsize)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (*in++ != 0) ? 255 : 0;
}
static void
l2i(UINT8* out_, const UINT8* in, int xsize)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (INT32) *in++;
}
static void
i2l(UINT8* out, const UINT8* in_, int xsize)
{
int x;
INT32* in = (INT32*) in_;
for (x = 0; x < xsize; x++, in++, out++) {
if (*in <= 0)
*out = 0;
else if (*in >= 255)
*out = 255;
else
*out = (UINT8) *in;
}
}
static void
i2f(UINT8* out_, const UINT8* in_, int xsize)
{
int x;
INT32* in = (INT32*) in_;
FLOAT32* out = (FLOAT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (FLOAT32) *in++;
}
/* ------------- */
/* F conversions */
/* ------------- */
static void
bit2f(UINT8* out_, const UINT8* in, int xsize)
{
int x;
FLOAT32* out = (FLOAT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (*in++ != 0) ? 255.0F : 0.0F;
}
static void
l2f(UINT8* out_, const UINT8* in, int xsize)
{
int x;
FLOAT32* out = (FLOAT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (FLOAT32) *in++;
}
static void
f2l(UINT8* out, const UINT8* in_, int xsize)
{
int x;
FLOAT32* in = (FLOAT32*) in_;
for (x = 0; x < xsize; x++, in++, out++) {
if (*in <= 0.0)
*out = 0;
else if (*in >= 255.0)
*out = 255;
else
*out = (UINT8) *in;
}
}
static void
f2i(UINT8* out_, const UINT8* in_, int xsize)
{
int x;
FLOAT32* in = (FLOAT32*) in_;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (INT32) *in++;
}
/* ----------------- */
/* YCbCr conversions */
/* ----------------- */
/* See ConvertYCbCr.c for RGB/YCbCr tables */
static void
l2ycbcr(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++) {
*out++ = *in++;
*out++ = 128;
*out++ = 128;
*out++ = 255;
}
}
static void
ycbcr2l(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 4)
*out++ = in[0];
}
/* ------------------------- */
/* I;16 (16-bit) conversions */
/* ------------------------- */
static void
I_I16L(UINT8* out, const UINT8* in_, int xsize)
{
int x, v;
INT32* in = (INT32*) in_;
for (x = 0; x < xsize; x++, in++) {
v = CLIP16(*in);
*out++ = (UINT8) v;
*out++ = (UINT8) (v >> 8);
}
}
static void
I_I16B(UINT8* out, const UINT8* in_, int xsize)
{
int x, v;
INT32* in = (INT32*) in_;
for (x = 0; x < xsize; x++, in++) {
v = CLIP16(*in);
*out++ = (UINT8) (v >> 8);
*out++ = (UINT8) v;
}
}
static void
I16L_I(UINT8* out_, const UINT8* in, int xsize)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++, in += 2)
*out++ = in[0] + ((int) in[1] << 8);
}
static void
I16B_I(UINT8* out_, const UINT8* in, int xsize)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++, in += 2)
*out++ = in[1] + ((int) in[0] << 8);
}
static void
L_I16L(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in++) {
*out++ = *in;
*out++ = 0;
}
}
static void
L_I16B(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in++) {
*out++ = 0;
*out++ = *in;
}
}
static void
I16L_L(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 2)
if (in[1] != 0)
*out++ = 255;
else
*out++ = in[0];
}
static void
I16B_L(UINT8* out, const UINT8* in, int xsize)
{
int x;
for (x = 0; x < xsize; x++, in += 2)
if (in[0] != 0)
*out++ = 255;
else
*out++ = in[1];
}
static struct {
const char* from;
const char* to;
ImagingShuffler convert;
} converters[] = {
{ "1", "L", bit2l },
{ "1", "I", bit2i },
{ "1", "F", bit2f },
{ "1", "RGB", bit2rgb },
{ "1", "RGBA", bit2rgb },
{ "1", "RGBX", bit2rgb },
{ "1", "CMYK", bit2cmyk },
{ "1", "YCbCr", bit2ycbcr },
{ "L", "1", l2bit },
{ "L", "LA", l2la },
{ "L", "I", l2i },
{ "L", "F", l2f },
{ "L", "RGB", l2rgb },
{ "L", "RGBA", l2rgb },
{ "L", "RGBX", l2rgb },
{ "L", "CMYK", l2cmyk },
{ "L", "YCbCr", l2ycbcr },
{ "LA", "L", la2l },
{ "LA", "RGB", la2rgb },
{ "LA", "RGBX", la2rgb },
{ "LA", "RGBA", la2rgb },
{ "I", "L", i2l },
{ "I", "F", i2f },
{ "F", "L", f2l },
{ "F", "I", f2i },
{ "RGB", "1", rgb2bit },
{ "RGB", "L", rgb2l },
{ "RGB", "LA", rgb2la },
{ "RGB", "I", rgb2i },
{ "RGB", "F", rgb2f },
{ "RGB", "BGR;15", rgb2bgr15 },
{ "RGB", "BGR;16", rgb2bgr16 },
{ "RGB", "BGR;24", rgb2bgr24 },
{ "RGB", "RGBA", rgb2rgba },
{ "RGB", "RGBX", rgb2rgba },
{ "RGB", "CMYK", rgb2cmyk },
{ "RGB", "YCbCr", ImagingConvertRGB2YCbCr },
{ "RGBA", "1", rgb2bit },
{ "RGBA", "L", rgb2l },
{ "RGBA", "LA", rgba2la },
{ "RGBA", "I", rgb2i },
{ "RGBA", "F", rgb2f },
{ "RGBA", "RGB", rgba2rgb },
{ "RGBA", "RGBa", rgba2rgba },
{ "RGBA", "RGBX", rgb2rgba },
{ "RGBA", "CMYK", rgb2cmyk },
{ "RGBA", "YCbCr", ImagingConvertRGB2YCbCr },
{ "RGBX", "1", rgb2bit },
{ "RGBX", "L", rgb2l },
{ "RGBA", "I", rgb2i },
{ "RGBA", "F", rgb2f },
{ "RGBX", "RGB", rgba2rgb },
{ "RGBX", "CMYK", rgb2cmyk },
{ "RGBX", "YCbCr", ImagingConvertRGB2YCbCr },
{ "CMYK", "RGB", cmyk2rgb },
{ "CMYK", "RGBA", cmyk2rgb },
{ "CMYK", "RGBX", cmyk2rgb },
{ "YCbCr", "L", ycbcr2l },
{ "YCbCr", "RGB", ImagingConvertYCbCr2RGB },
{ "I", "I;16", I_I16L },
{ "I;16", "I", I16L_I },
{ "L", "I;16", L_I16L },
{ "I;16", "L", I16L_L },
{ "I", "I;16L", I_I16L },
{ "I;16L", "I", I16L_I },
{ "I", "I;16B", I_I16B },
{ "I;16B", "I", I16B_I },
{ "L", "I;16L", L_I16L },
{ "I;16L", "L", I16L_L },
{ "L", "I;16B", L_I16B },
{ "I;16B", "L", I16B_L },
{ NULL }
};
/* FIXME: translate indexed versions to pointer versions below this line */
/* ------------------- */
/* Palette conversions */
/* ------------------- */
static void
p2bit(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
/* FIXME: precalculate greyscale palette? */
for (x = 0; x < xsize; x++)
*out++ = (L(&palette[in[x]*4]) >= 128000) ? 255 : 0;
}
static void
p2l(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
/* FIXME: precalculate greyscale palette? */
for (x = 0; x < xsize; x++)
*out++ = L(&palette[in[x]*4]) / 1000;
}
static void
pa2la(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
/* FIXME: precalculate greyscale palette? */
for (x = 0; x < xsize; x++, in += 2) {
*out++ = L(&palette[in[0]*4]) / 1000;
*out++ = in[1];
}
}
static void
p2i(UINT8* out_, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
INT32* out = (INT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = L(&palette[in[x]*4]) / 1000;
}
static void
p2f(UINT8* out_, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
FLOAT32* out = (FLOAT32*) out_;
for (x = 0; x < xsize; x++)
*out++ = (float) L(&palette[in[x]*4]) / 1000.0F;
}
static void
p2rgb(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
for (x = 0; x < xsize; x++) {
const UINT8* rgb = &palette[*in++ * 4];
*out++ = rgb[0];
*out++ = rgb[1];
*out++ = rgb[2];
*out++ = 255;
}
}
static void
p2rgba(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
for (x = 0; x < xsize; x++) {
const UINT8* rgba = &palette[*in++ * 4];
*out++ = rgba[0];
*out++ = rgba[1];
*out++ = rgba[2];
*out++ = rgba[3];
}
}
static void
pa2rgba(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
int x;
for (x = 0; x < xsize; x++, in += 4) {
const UINT8* rgb = &palette[in[0] * 4];
*out++ = rgb[0];
*out++ = rgb[1];
*out++ = rgb[2];
*out++ = in[3];
}
}
static void
p2cmyk(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
p2rgb(out, in, xsize, palette);
rgb2cmyk(out, out, xsize);
}
static void
p2ycbcr(UINT8* out, const UINT8* in, int xsize, const UINT8* palette)
{
p2rgb(out, in, xsize, palette);
ImagingConvertRGB2YCbCr(out, out, xsize);
}
static Imaging
frompalette(Imaging imOut, Imaging imIn, const char *mode)
{
ImagingSectionCookie cookie;
int alpha;
int y;
void (*convert)(UINT8*, const UINT8*, int, const UINT8*);
/* Map palette image to L, RGB, RGBA, or CMYK */
if (!imIn->palette)
return (Imaging) ImagingError_ValueError("no palette");
alpha = !strcmp(imIn->mode, "PA");
if (strcmp(mode, "1") == 0)
convert = p2bit;
else if (strcmp(mode, "L") == 0)
convert = p2l;
else if (strcmp(mode, "LA") == 0)
convert = (alpha) ? pa2la : p2l;
else if (strcmp(mode, "I") == 0)
convert = p2i;
else if (strcmp(mode, "F") == 0)
convert = p2f;
else if (strcmp(mode, "RGB") == 0)
convert = p2rgb;
else if (strcmp(mode, "RGBA") == 0)
convert = (alpha) ? pa2rgba : p2rgba;
else if (strcmp(mode, "RGBX") == 0)
convert = p2rgba;
else if (strcmp(mode, "CMYK") == 0)
convert = p2cmyk;
else if (strcmp(mode, "YCbCr") == 0)
convert = p2ycbcr;
else
return (Imaging) ImagingError_ValueError("conversion not supported");
imOut = ImagingNew2(mode, imOut, imIn);
if (!imOut)
return NULL;
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++)
(*convert)((UINT8*) imOut->image[y], (UINT8*) imIn->image[y],
imIn->xsize, imIn->palette->palette);
ImagingSectionLeave(&cookie);
return imOut;
}
static Imaging
topalette(Imaging imOut, Imaging imIn, ImagingPalette inpalette, int dither)
{
ImagingSectionCookie cookie;
int x, y;
ImagingPalette palette = inpalette;;
/* Map L or RGB/RGBX/RGBA to palette image */
if (strcmp(imIn->mode, "L") != 0 && strncmp(imIn->mode, "RGB", 3) != 0)
return (Imaging) ImagingError_ValueError("conversion not supported");
if (palette == NULL) {
/* FIXME: make user configurable */
if (imIn->bands == 1)
palette = ImagingPaletteNew("RGB"); /* Initialised to grey ramp */
else
palette = ImagingPaletteNewBrowser(); /* Standard colour cube */
}
if (!palette)
return (Imaging) ImagingError_ValueError("no palette");
imOut = ImagingNew2("P", imOut, imIn);
if (!imOut) {
if (palette != inpalette)
ImagingPaletteDelete(palette);
return NULL;
}
ImagingPaletteDelete(imOut->palette);
imOut->palette = ImagingPaletteDuplicate(palette);
if (imIn->bands == 1) {
/* greyscale image */
/* Greyscale palette: copy data as is */
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++)
memcpy(imOut->image[y], imIn->image[y], imIn->linesize);
ImagingSectionLeave(&cookie);
} else {
/* colour image */
/* Create mapping cache */
if (ImagingPaletteCachePrepare(palette) < 0) {
ImagingDelete(imOut);
if (palette != inpalette)
ImagingPaletteDelete(palette);
return NULL;
}
if (dither) {
/* floyd-steinberg dither */
int* errors;
errors = calloc(imIn->xsize + 1, sizeof(int) * 3);
if (!errors) {
ImagingDelete(imOut);
return ImagingError_MemoryError();
}
/* Map each pixel to the nearest palette entry */
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
int r, r0, r1, r2;
int g, g0, g1, g2;
int b, b0, b1, b2;
UINT8* in = (UINT8*) imIn->image[y];
UINT8* out = imOut->image8[y];
int* e = errors;
r = r0 = r1 = 0;
g = g0 = g1 = 0;
b = b0 = b1 = b2 = 0;
for (x = 0; x < imIn->xsize; x++, in += 4) {
int d2;
INT16* cache;
r = CLIP(in[0] + (r + e[3+0])/16);
g = CLIP(in[1] + (g + e[3+1])/16);
b = CLIP(in[2] + (b + e[3+2])/16);
/* get closest colour */
cache = &ImagingPaletteCache(palette, r, g, b);
if (cache[0] == 0x100)
ImagingPaletteCacheUpdate(palette, r, g, b);
out[x] = (UINT8) cache[0];
r -= (int) palette->palette[cache[0]*4];
g -= (int) palette->palette[cache[0]*4+1];
b -= (int) palette->palette[cache[0]*4+2];
/* propagate errors (don't ask ;-) */
r2 = r; d2 = r + r; r += d2; e[0] = r + r0;
r += d2; r0 = r + r1; r1 = r2; r += d2;
g2 = g; d2 = g + g; g += d2; e[1] = g + g0;
g += d2; g0 = g + g1; g1 = g2; g += d2;
b2 = b; d2 = b + b; b += d2; e[2] = b + b0;
b += d2; b0 = b + b1; b1 = b2; b += d2;
e += 3;
}
e[0] = b0;
e[1] = b1;
e[2] = b2;
}
ImagingSectionLeave(&cookie);
free(errors);
} else {
/* closest colour */
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
int r, g, b;
UINT8* in = (UINT8*) imIn->image[y];
UINT8* out = imOut->image8[y];
for (x = 0; x < imIn->xsize; x++, in += 4) {
INT16* cache;
r = in[0]; g = in[1]; b = in[2];
/* get closest colour */
cache = &ImagingPaletteCache(palette, r, g, b);
if (cache[0] == 0x100)
ImagingPaletteCacheUpdate(palette, r, g, b);
out[x] = (UINT8) cache[0];
}
}
ImagingSectionLeave(&cookie);
}
if (inpalette != palette)
ImagingPaletteCacheDelete(palette);
}
if (inpalette != palette)
ImagingPaletteDelete(palette);
return imOut;
}
static Imaging
tobilevel(Imaging imOut, Imaging imIn, int dither)
{
ImagingSectionCookie cookie;
int x, y;
int* errors;
/* Map L or RGB to dithered 1 image */
if (strcmp(imIn->mode, "L") != 0 && strcmp(imIn->mode, "RGB") != 0)
return (Imaging) ImagingError_ValueError("conversion not supported");
imOut = ImagingNew2("1", imOut, imIn);
if (!imOut)
return NULL;
errors = calloc(imIn->xsize + 1, sizeof(int));
if (!errors) {
ImagingDelete(imOut);
return ImagingError_MemoryError();
}
if (imIn->bands == 1) {
/* map each pixel to black or white, using error diffusion */
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
int l, l0, l1, l2, d2;
UINT8* in = (UINT8*) imIn->image[y];
UINT8* out = imOut->image8[y];
l = l0 = l1 = 0;
for (x = 0; x < imIn->xsize; x++) {
/* pick closest colour */
l = CLIP(in[x] + (l + errors[x+1])/16);
out[x] = (l > 128) ? 255 : 0;
/* propagate errors */
l -= (int) out[x];
l2 = l; d2 = l + l; l += d2; errors[x] = l + l0;
l += d2; l0 = l + l1; l1 = l2; l += d2;
}
errors[x] = l0;
}
ImagingSectionLeave(&cookie);
} else {
/* map each pixel to black or white, using error diffusion */
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
int l, l0, l1, l2, d2;
UINT8* in = (UINT8*) imIn->image[y];
UINT8* out = imOut->image8[y];
l = l0 = l1 = 0;
for (x = 0; x < imIn->xsize; x++, in += 4) {
/* pick closest colour */
l = CLIP(L(in)/1000 + (l + errors[x+1])/16);
out[x] = (l > 128) ? 255 : 0;
/* propagate errors */
l -= (int) out[x];
l2 = l; d2 = l + l; l += d2; errors[x] = l + l0;
l += d2; l0 = l + l1; l1 = l2; l += d2;
}
errors[x] = l0;
}
ImagingSectionLeave(&cookie);
}
free(errors);
return imOut;
}
static Imaging
convert(Imaging imOut, Imaging imIn, const char *mode,
ImagingPalette palette, int dither)
{
ImagingSectionCookie cookie;
ImagingShuffler convert;
int y;
if (!imIn)
return (Imaging) ImagingError_ModeError();
if (!mode) {
/* Map palette image to full depth */
if (!imIn->palette)
return (Imaging) ImagingError_ModeError();
mode = imIn->palette->mode;
} else
/* Same mode? */
if (!strcmp(imIn->mode, mode))
return ImagingCopy2(imOut, imIn);
/* test for special conversions */
if (strcmp(imIn->mode, "P") == 0 || strcmp(imIn->mode, "PA") == 0)
return frompalette(imOut, imIn, mode);
if (strcmp(mode, "P") == 0)
return topalette(imOut, imIn, palette, dither);
if (dither && strcmp(mode, "1") == 0)
return tobilevel(imOut, imIn, dither);
/* standard conversion machinery */
convert = NULL;
for (y = 0; converters[y].from; y++)
if (!strcmp(imIn->mode, converters[y].from) &&
!strcmp(mode, converters[y].to)) {
convert = converters[y].convert;
break;
}
if (!convert)
#ifdef notdef
return (Imaging) ImagingError_ValueError("conversion not supported");
#else
{
static char buf[256];
/* FIXME: may overflow if mode is too large */
sprintf(buf, "conversion from %s to %s not supported", imIn->mode, mode);
return (Imaging) ImagingError_ValueError(buf);
}
#endif
imOut = ImagingNew2(mode, imOut, imIn);
if (!imOut)
return NULL;
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++)
(*convert)((UINT8*) imOut->image[y], (UINT8*) imIn->image[y],
imIn->xsize);
ImagingSectionLeave(&cookie);
return imOut;
}
Imaging
ImagingConvert(Imaging imIn, const char *mode,
ImagingPalette palette, int dither)
{
return convert(NULL, imIn, mode, palette, dither);
}
Imaging
ImagingConvert2(Imaging imOut, Imaging imIn)
{
return convert(imOut, imIn, imOut->mode, NULL, 0);
}
Imaging
ImagingConvertInPlace(Imaging imIn, const char* mode)
{
ImagingSectionCookie cookie;
ImagingShuffler convert;
int y;
/* limited support for inplace conversion */
if (strcmp(imIn->mode, "L") == 0 && strcmp(mode, "1") == 0)
convert = l2bit;
else if (strcmp(imIn->mode, "1") == 0 && strcmp(mode, "L") == 0)
convert = bit2l;
else
return ImagingError_ModeError();
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++)
(*convert)((UINT8*) imIn->image[y], (UINT8*) imIn->image[y],
imIn->xsize);
ImagingSectionLeave(&cookie);
return imIn;
}
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