Imaging
ImagingEffectSpread(Imaging imIn, int distance)
{
/* Randomly spread pixels in an image */
Imaging imOut;
int x, y;
imOut = ImagingNew(imIn->mode, imIn->xsize, imIn->ysize);
if (!imOut)
return NULL;
#define SPREAD(type, image)\
for (y = 0; y < imIn->ysize; y++)\
for (x = 0; x < imIn->xsize; x++) {\
int xx = x + (rand() % distance) - distance/2;\
int yy = y + (rand() % distance) - distance/2;\
if (xx >= 0 && xx < imIn->xsize && yy >= 0 && yy < imIn->ysize) {\
imOut->image[yy][xx] = imIn->image[y][x];\
imOut->image[y][x] = imIn->image[yy][xx];\
} else\
imOut->image[y][x] = imIn->image[y][x];\
}
if (imIn->image8) {
SPREAD(UINT8, image8);
} else {
SPREAD(INT32, image32);
}
ImagingCopyInfo(imOut, imIn);
return imOut;
}
Imaging
ImagingBlend(Imaging imIn1, Imaging imIn2, float alpha)
{
Imaging imOut;
int x, y;
/* Check arguments */
if (!imIn1 || !imIn2 || imIn1->type != IMAGING_TYPE_UINT8)
return ImagingError_ModeError();
if (imIn1->type != imIn2->type ||
imIn1->bands != imIn2->bands ||
imIn1->xsize != imIn2->xsize ||
imIn1->ysize != imIn2->ysize)
return ImagingError_Mismatch();
/* Shortcuts */
if (alpha == 0.0)
return ImagingCopy(imIn1);
else if (alpha == 1.0)
return ImagingCopy(imIn2);
imOut = ImagingNew(imIn1->mode, imIn1->xsize, imIn1->ysize);
if (!imOut)
return NULL;
ImagingCopyInfo(imOut, imIn1);
if (alpha >= 0 && alpha <= 1.0) {
/* Interpolate between bands */
for (y = 0; y < imIn1->ysize; y++) {
UINT8* in1 = (UINT8*) imIn1->image[y];
UINT8* in2 = (UINT8*) imIn2->image[y];
UINT8* out = (UINT8*) imOut->image[y];
for (x = 0; x < imIn1->linesize; x++)
out[x] = (UINT8)
((int) in1[x] + alpha * ((int) in2[x] - (int) in1[x]));
}
} else {
/* Extrapolation; must make sure to clip resulting values */
for (y = 0; y < imIn1->ysize; y++) {
UINT8* in1 = (UINT8*) imIn1->image[y];
UINT8* in2 = (UINT8*) imIn2->image[y];
UINT8* out = (UINT8*) imOut->image[y];
for (x = 0; x < imIn1->linesize; x++) {
float temp =
((int) in1[x] + alpha * ((int) in2[x] - (int) in1[x]));
if (temp <= 0.0)
out[x] = 0;
else if (temp >= 255.0)
out[x] = 255;
else
out[x] = (UINT8) temp;
}
}
}
return imOut;
}
Imaging
ImagingRankFilter(Imaging im, int size, int rank)
{
Imaging imOut = NULL;
int x, y;
int i, margin, size2;
if (!im || im->bands != 1 || im->type == IMAGING_TYPE_SPECIAL)
return (Imaging) ImagingError_ModeError();
if (!(size & 1))
return (Imaging) ImagingError_ValueError("bad filter size");
size2 = size * size;
margin = (size-1) / 2;
if (rank < 0 || rank >= size2)
return (Imaging) ImagingError_ValueError("bad rank value");
imOut = ImagingNew(im->mode, im->xsize - 2*margin, im->ysize - 2*margin);
if (!imOut)
return NULL;
#define RANK_BODY(type) do {\
type* buf = malloc(size2 * sizeof(type));\
if (!buf)\
goto nomemory;\
for (y = 0; y < imOut->ysize; y++)\
for (x = 0; x < imOut->xsize; x++) {\
for (i = 0; i < size; i++)\
memcpy(buf + i*size, &IMAGING_PIXEL_##type(im, x, y+i),\
size * sizeof(type));\
IMAGING_PIXEL_##type(imOut, x, y) = Rank##type(buf, size2, rank);\
}\
} while (0)
if (im->image8)
RANK_BODY(UINT8);
else if (im->type == IMAGING_TYPE_INT32)
RANK_BODY(INT32);
else if (im->type == IMAGING_TYPE_FLOAT32)
RANK_BODY(FLOAT32);
else {
/* safety net (we shouldn't end up here) */
ImagingDelete(imOut);
return (Imaging) ImagingError_ModeError();
}
ImagingCopyInfo(imOut, im);
return imOut;
nomemory:
ImagingDelete(imOut);
return (Imaging) ImagingError_MemoryError();
}
Imaging
ImagingExpand(Imaging imIn, int xmargin, int ymargin, int mode)
{
Imaging imOut;
int x, y;
if (xmargin < 0 && ymargin < 0)
return (Imaging) ImagingError_ValueError("bad kernel size");
imOut = ImagingNew(
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);\
}
if (imIn->image8) {
EXPAND(UINT8, image8);
} else {
EXPAND(INT32, image32);
}
ImagingCopyInfo(imOut, imIn);
return imOut;
}
Imaging
ImagingCrop(Imaging imIn, int sx0, int sy0, int sx1, int sy1)
{
Imaging imOut;
int xsize, ysize;
int dx0, dy0, dx1, dy1;
INT32 zero = 0;
if (!imIn)
return (Imaging) ImagingError_ModeError();
xsize = sx1 - sx0;
if (xsize < 0)
xsize = 0;
ysize = sy1 - sy0;
if (ysize < 0)
ysize = 0;
imOut = ImagingNew(imIn->mode, xsize, ysize);
if (!imOut)
return NULL;
ImagingCopyInfo(imOut, imIn);
if (sx0 < 0 || sy0 < 0 || sx1 > imIn->xsize || sy1 > imIn->ysize)
(void) ImagingFill(imOut, &zero);
dx0 = -sx0;
dy0 = -sy0;
dx1 = imIn->xsize - sx0;
dy1 = imIn->ysize - sy0;
/* paste the source image on top of the output image!!! */
if (ImagingPaste(imOut, imIn, NULL, dx0, dy0, dx1, dy1) < 0) {
ImagingDelete(imOut);
return NULL;
}
return imOut;
}
Imaging
ImagingAlphaComposite(Imaging imDst, Imaging imSrc)
{
Imaging imOut;
int x, y;
/* Check arguments */
if (!imDst || !imSrc ||
strcmp(imDst->mode, "RGBA") ||
imDst->type != IMAGING_TYPE_UINT8 ||
imDst->bands != 4)
return ImagingError_ModeError();
if (strcmp(imDst->mode, imSrc->mode) ||
imDst->type != imSrc->type ||
imDst->bands != imSrc->bands ||
imDst->xsize != imSrc->xsize ||
imDst->ysize != imSrc->ysize)
return ImagingError_Mismatch();
imOut = ImagingNew(imDst->mode, imDst->xsize, imDst->ysize);
if (!imOut)
return NULL;
ImagingCopyInfo(imOut, imDst);
for (y = 0; y < imDst->ysize; y++) {
rgba8* dst = (rgba8*) imDst->image[y];
rgba8* src = (rgba8*) imSrc->image[y];
rgba8* out = (rgba8*) imOut->image[y];
for (x = 0; x < imDst->xsize; x ++) {
if (src->a == 0) {
// Copy 4 bytes at once.
*out = *dst;
} else {
// Integer implementation with increased precision.
// Each variable has extra meaningful bits.
// Divisions are rounded.
// This code uses trick from Paste.c:
// (a + (2 << (n-1)) - 1) / ((2 << n)-1)
// almost equivalent to:
// tmp = a + (2 << (n-1)), ((tmp >> n) + tmp) >> n
UINT16 blend = dst->a * (255 - src->a);
UINT16 outa255 = src->a * 255 + blend;
// There we use 7 bits for precision.
// We could use more, but we go beyond 32 bits.
UINT16 coef1 = src->a * 255 * 255 * 128 / outa255;
UINT16 coef2 = blend * 255 * 128 / outa255;
#define SHIFTFORDIV255(a)\
((a >> 8) + a >> 8)
UINT32 tmpr = src->r * coef1 + dst->r * coef2 + (0x80 << 7);
out->r = SHIFTFORDIV255(tmpr) >> 7;
UINT32 tmpg = src->g * coef1 + dst->g * coef2 + (0x80 << 7);
out->g = SHIFTFORDIV255(tmpg) >> 7;
UINT32 tmpb = src->b * coef1 + dst->b * coef2 + (0x80 << 7);
out->b = SHIFTFORDIV255(tmpb) >> 7;
out->a = SHIFTFORDIV255(outa255 + 0x80);
}
dst++; src++; out++;
}
}
return imOut;
}
Imaging
ImagingPointTransform(Imaging imIn, double scale, double offset)
{
/* scale/offset transform */
ImagingSectionCookie cookie;
Imaging imOut;
int x, y;
if (!imIn || (strcmp(imIn->mode, "I") != 0 &&
strcmp(imIn->mode, "I;16") != 0 &&
strcmp(imIn->mode, "F") != 0))
return (Imaging) ImagingError_ModeError();
imOut = ImagingNew(imIn->mode, imIn->xsize, imIn->ysize);
if (!imOut)
return NULL;
ImagingCopyInfo(imOut, imIn);
switch (imIn->type) {
case IMAGING_TYPE_INT32:
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
INT32* in = imIn->image32[y];
INT32* out = imOut->image32[y];
/* FIXME: add clipping? */
for (x = 0; x < imIn->xsize; x++)
out[x] = in[x] * scale + offset;
}
ImagingSectionLeave(&cookie);
break;
case IMAGING_TYPE_FLOAT32:
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
FLOAT32* in = (FLOAT32*) imIn->image32[y];
FLOAT32* out = (FLOAT32*) imOut->image32[y];
for (x = 0; x < imIn->xsize; x++)
out[x] = in[x] * scale + offset;
}
ImagingSectionLeave(&cookie);
break;
case IMAGING_TYPE_SPECIAL:
if (strcmp(imIn->mode,"I;16") == 0) {
ImagingSectionEnter(&cookie);
for (y = 0; y < imIn->ysize; y++) {
UINT16* in = (UINT16 *)imIn->image[y];
UINT16* out = (UINT16 *)imOut->image[y];
/* FIXME: add clipping? */
for (x = 0; x < imIn->xsize; x++)
out[x] = in[x] * scale + offset;
}
ImagingSectionLeave(&cookie);
break;
}
/* FALL THROUGH */
default:
ImagingDelete(imOut);
return (Imaging) ImagingError_ValueError("internal error");
}
return imOut;
}
Imaging
ImagingPoint(Imaging imIn, const char* mode, const void* table)
{
/* lookup table transform */
ImagingSectionCookie cookie;
Imaging imOut;
im_point_context context;
void (*point)(Imaging imIn, Imaging imOut, im_point_context* context);
if (!imIn)
return (Imaging) ImagingError_ModeError();
if (!mode)
mode = imIn->mode;
if (imIn->type != IMAGING_TYPE_UINT8) {
if (imIn->type != IMAGING_TYPE_INT32 || strcmp(mode, "L") != 0)
goto mode_mismatch;
} else if (!imIn->image8 && strcmp(imIn->mode, mode) != 0)
goto mode_mismatch;
imOut = ImagingNew(mode, imIn->xsize, imIn->ysize);
if (!imOut)
return NULL;
/* find appropriate handler */
if (imIn->type == IMAGING_TYPE_UINT8) {
if (imIn->bands == imOut->bands && imIn->type == imOut->type) {
switch (imIn->bands) {
case 1:
point = im_point_8_8;
break;
case 2:
point = im_point_2x8_2x8;
break;
case 3:
point = im_point_3x8_3x8;
break;
case 4:
point = im_point_4x8_4x8;
break;
default:
/* this cannot really happen */
point = im_point_8_8;
break;
}
} else
point = im_point_8_32;
} else
point = im_point_32_8;
ImagingCopyInfo(imOut, imIn);
ImagingSectionEnter(&cookie);
context.table = table;
point(imOut, imIn, &context);
ImagingSectionLeave(&cookie);
return imOut;
mode_mismatch:
return (Imaging) ImagingError_ValueError(
"point operation not supported for this mode"
);
}
