Pillow/src/libImaging/Matrix.c
2020-05-10 19:56:36 +10:00

79 lines
2.0 KiB
C

/*
* The Python Imaging Library
* $Id$
*
* colour and luminance matrix transforms
*
* history:
* 1996-05-18 fl: created (brute force implementation)
*
* Copyright (c) Fredrik Lundh 1996.
* Copyright (c) Secret Labs AB 1997.
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
#define CLIPF(v) ((v <= 0.0) ? 0 : (v >= 255.0F) ? 255 : (UINT8) v)
Imaging
ImagingConvertMatrix(Imaging im, const char *mode, float m[])
{
Imaging imOut;
int x, y;
/* Assume there's enough data in the buffer */
if (!im) {
return (Imaging) ImagingError_ModeError();
}
if (strcmp(mode, "L") == 0 && im->bands == 3) {
imOut = ImagingNewDirty("L", im->xsize, im->ysize);
if (!imOut) {
return NULL;
}
for (y = 0; y < im->ysize; y++) {
UINT8* in = (UINT8*) im->image[y];
UINT8* out = (UINT8*) imOut->image[y];
for (x = 0; x < im->xsize; x++) {
float v = m[0]*in[0] + m[1]*in[1] + m[2]*in[2] + m[3] + 0.5;
out[x] = CLIPF(v);
in += 4;
}
}
} else if (strlen(mode) == 3 && im->bands == 3) {
imOut = ImagingNewDirty(mode, im->xsize, im->ysize);
if (!imOut) {
return NULL;
}
for (y = 0; y < im->ysize; y++) {
UINT8* in = (UINT8*) im->image[y];
UINT8* out = (UINT8*) imOut->image[y];
for (x = 0; x < im->xsize; x++) {
float v0 = m[0]*in[0] + m[1]*in[1] + m[2]*in[2] + m[3] + 0.5;
float v1 = m[4]*in[0] + m[5]*in[1] + m[6]*in[2] + m[7] + 0.5;
float v2 = m[8]*in[0] + m[9]*in[1] + m[10]*in[2] + m[11] + 0.5;
out[0] = CLIPF(v0);
out[1] = CLIPF(v1);
out[2] = CLIPF(v2);
in += 4; out += 4;
}
}
} else {
return (Imaging) ImagingError_ModeError();
}
return imOut;
}