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
ImagingNew2Dirty(const char* mode, Imaging imOut, Imaging imIn)
{
/* allocate or validate output image */
if (imOut) {
/* make sure images match */
if (strcmp(imOut->mode, mode) != 0
|| imOut->xsize != imIn->xsize
|| imOut->ysize != imIn->ysize) {
return ImagingError_Mismatch();
}
} else {
/* create new image */
imOut = ImagingNewDirty(mode, imIn->xsize, imIn->ysize);
if (!imOut)
return NULL;
}
return imOut;
}
Imaging
ImagingPutBand(Imaging imOut, Imaging imIn, int band)
{
int x, y;
/* Check arguments */
if (!imIn || imIn->bands != 1 || !imOut)
return (Imaging) ImagingError_ModeError();
if (band < 0 || band >= imOut->bands)
return (Imaging) ImagingError_ValueError("band index out of range");
if (imIn->type != imOut->type ||
imIn->xsize != imOut->xsize ||
imIn->ysize != imOut->ysize)
return (Imaging) ImagingError_Mismatch();
/* Shortcuts */
if (imOut->bands == 1)
return ImagingCopy2(imOut, imIn);
/* Special case for LXXA etc */
if (imOut->bands == 2 && band == 1)
band = 3;
/* Insert band into image */
for (y = 0; y < imIn->ysize; y++) {
UINT8* in = imIn->image8[y];
UINT8* out = (UINT8*) imOut->image[y] + band;
for (x = 0; x < imIn->xsize; x++) {
*out = in[x];
out += 4;
}
}
return imOut;
}
int
ImagingFill2(Imaging imOut, const void* ink, Imaging imMask,
int dx0, int dy0, int dx1, int dy1)
{
ImagingSectionCookie cookie;
int xsize, ysize;
int pixelsize;
int sx0, sy0;
if (!imOut || !ink) {
(void) ImagingError_ModeError();
return -1;
}
pixelsize = imOut->pixelsize;
xsize = dx1 - dx0;
ysize = dy1 - dy0;
if (imMask && (xsize != imMask->xsize || ysize != imMask->ysize)) {
(void) ImagingError_Mismatch();
return -1;
}
/* Determine which region to fill */
sx0 = sy0 = 0;
if (dx0 < 0)
xsize += dx0, sx0 = -dx0, dx0 = 0;
if (dx0 + xsize > imOut->xsize)
xsize = imOut->xsize - dx0;
if (dy0 < 0)
ysize += dy0, sy0 = -dy0, dy0 = 0;
if (dy0 + ysize > imOut->ysize)
ysize = imOut->ysize - dy0;
if (xsize <= 0 || ysize <= 0)
return 0;
if (!imMask) {
ImagingSectionEnter(&cookie);
fill(imOut, ink, dx0, dy0, xsize, ysize, pixelsize);
ImagingSectionLeave(&cookie);
} else if (strcmp(imMask->mode, "1") == 0) {
ImagingSectionEnter(&cookie);
fill_mask_1(imOut, ink, imMask, dx0, dy0, sx0, sy0,
xsize, ysize, pixelsize);
ImagingSectionLeave(&cookie);
} else if (strcmp(imMask->mode, "L") == 0) {
ImagingSectionEnter(&cookie);
fill_mask_L(imOut, ink, imMask, dx0, dy0, sx0, sy0,
xsize, ysize, pixelsize);
ImagingSectionLeave(&cookie);
} else if (strcmp(imMask->mode, "RGBA") == 0) {
ImagingSectionEnter(&cookie);
fill_mask_RGBA(imOut, ink, imMask, dx0, dy0, sx0, sy0,
xsize, ysize, pixelsize);
ImagingSectionLeave(&cookie);
} else if (strcmp(imMask->mode, "RGBa") == 0) {
ImagingSectionEnter(&cookie);
fill_mask_RGBa(imOut, ink, imMask, dx0, dy0, sx0, sy0,
xsize, ysize, pixelsize);
ImagingSectionLeave(&cookie);
} else {
(void) ImagingError_ValueError("bad transparency mask");
return -1;
}
return 0;
}
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
ImagingStretch(Imaging imOut, Imaging imIn, int filter)
{
/* FIXME: this is a quick and straightforward translation from a
python prototype. might need some further C-ification... */
ImagingSectionCookie cookie;
struct filter *filterp;
float support, scale, filterscale;
float center, ww, ss, ymin, ymax, xmin, xmax;
int xx, yy, x, y, b;
float *k;
/* check modes */
if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
return (Imaging) ImagingError_ModeError();
/* check filter */
switch (filter) {
case IMAGING_TRANSFORM_NEAREST:
filterp = &NEAREST;
break;
case IMAGING_TRANSFORM_ANTIALIAS:
filterp = &ANTIALIAS;
break;
case IMAGING_TRANSFORM_BILINEAR:
filterp = &BILINEAR;
break;
case IMAGING_TRANSFORM_BICUBIC:
filterp = &BICUBIC;
break;
default:
return (Imaging) ImagingError_ValueError(
"unsupported resampling filter"
);
}
if (imIn->ysize == imOut->ysize) {
/* prepare for horizontal stretch */
filterscale = scale = (float) imIn->xsize / imOut->xsize;
} else if (imIn->xsize == imOut->xsize) {
/* prepare for vertical stretch */
filterscale = scale = (float) imIn->ysize / imOut->ysize;
} else
return (Imaging) ImagingError_Mismatch();
/* determine support size (length of resampling filter) */
support = filterp->support;
if (filterscale < 1.0) {
filterscale = 1.0;
support = 0.5;
}
support = support * filterscale;
/* coefficient buffer (with rounding safety margin) */
k = malloc(((int) support * 2 + 10) * sizeof(float));
if (!k)
return (Imaging) ImagingError_MemoryError();
ImagingSectionEnter(&cookie);
if (imIn->xsize == imOut->xsize) {
/* vertical stretch */
for (yy = 0; yy < imOut->ysize; yy++) {
center = (yy + 0.5) * scale;
ww = 0.0;
ss = 1.0 / filterscale;
/* calculate filter weights */
ymin = floor(center - support);
if (ymin < 0.0)
ymin = 0.0;
ymax = ceil(center + support);
if (ymax > (float) imIn->ysize)
ymax = (float) imIn->ysize;
for (y = (int) ymin; y < (int) ymax; y++) {
float w = filterp->filter((y - center + 0.5) * ss) * ss;
k[y - (int) ymin] = w;
ww = ww + w;
}
if (ww == 0.0)
ww = 1.0;
else
ww = 1.0 / ww;
if (imIn->image8) {
/* 8-bit grayscale */
for (xx = 0; xx < imOut->xsize; xx++) {
ss = 0.0;
for (y = (int) ymin; y < (int) ymax; y++)
ss = ss + imIn->image8[y][xx] * k[y - (int) ymin];
ss = ss * ww + 0.5;
if (ss < 0.5)
imOut->image8[yy][xx] = 0;
else if (ss >= 255.0)
imOut->image8[yy][xx] = 255;
else
imOut->image8[yy][xx] = (UINT8) ss;
}
} else
switch(imIn->type) {
case IMAGING_TYPE_UINT8:
/* n-bit grayscale */
for (xx = 0; xx < imOut->xsize*4; xx++) {
/* FIXME: skip over unused pixels */
ss = 0.0;
for (y = (int) ymin; y < (int) ymax; y++)
ss = ss + (UINT8) imIn->image[y][xx] * k[y-(int) ymin];
ss = ss * ww + 0.5;
if (ss < 0.5)
imOut->image[yy][xx] = (UINT8) 0;
else if (ss >= 255.0)
imOut->image[yy][xx] = (UINT8) 255;
else
imOut->image[yy][xx] = (UINT8) ss;
}
break;
case IMAGING_TYPE_INT32:
/* 32-bit integer */
for (xx = 0; xx < imOut->xsize; xx++) {
ss = 0.0;
for (y = (int) ymin; y < (int) ymax; y++)
ss = ss + IMAGING_PIXEL_I(imIn, xx, y) * k[y - (int) ymin];
IMAGING_PIXEL_I(imOut, xx, yy) = (int) ss * ww;
}
break;
case IMAGING_TYPE_FLOAT32:
/* 32-bit float */
for (xx = 0; xx < imOut->xsize; xx++) {
ss = 0.0;
for (y = (int) ymin; y < (int) ymax; y++)
ss = ss + IMAGING_PIXEL_F(imIn, xx, y) * k[y - (int) ymin];
IMAGING_PIXEL_F(imOut, xx, yy) = ss * ww;
}
break;
default:
ImagingSectionLeave(&cookie);
return (Imaging) ImagingError_ModeError();
}
}
} else {
/* horizontal stretch */
for (xx = 0; xx < imOut->xsize; xx++) {
center = (xx + 0.5) * scale;
ww = 0.0;
ss = 1.0 / filterscale;
xmin = floor(center - support);
if (xmin < 0.0)
xmin = 0.0;
xmax = ceil(center + support);
if (xmax > (float) imIn->xsize)
xmax = (float) imIn->xsize;
for (x = (int) xmin; x < (int) xmax; x++) {
float w = filterp->filter((x - center + 0.5) * ss) * ss;
k[x - (int) xmin] = w;
ww = ww + w;
}
if (ww == 0.0)
ww = 1.0;
else
ww = 1.0 / ww;
if (imIn->image8) {
/* 8-bit grayscale */
for (yy = 0; yy < imOut->ysize; yy++) {
ss = 0.0;
for (x = (int) xmin; x < (int) xmax; x++)
ss = ss + imIn->image8[yy][x] * k[x - (int) xmin];
ss = ss * ww + 0.5;
if (ss < 0.5)
imOut->image8[yy][xx] = (UINT8) 0;
else if (ss >= 255.0)
imOut->image8[yy][xx] = (UINT8) 255;
else
imOut->image8[yy][xx] = (UINT8) ss;
}
} else
switch(imIn->type) {
case IMAGING_TYPE_UINT8:
/* n-bit grayscale */
for (yy = 0; yy < imOut->ysize; yy++) {
for (b = 0; b < imIn->bands; b++) {
if (imIn->bands == 2 && b)
b = 3; /* hack to deal with LA images */
ss = 0.0;
for (x = (int) xmin; x < (int) xmax; x++)
ss = ss + (UINT8) imIn->image[yy][x*4+b] * k[x - (int) xmin];
ss = ss * ww + 0.5;
if (ss < 0.5)
imOut->image[yy][xx*4+b] = (UINT8) 0;
else if (ss >= 255.0)
imOut->image[yy][xx*4+b] = (UINT8) 255;
else
imOut->image[yy][xx*4+b] = (UINT8) ss;
}
}
break;
case IMAGING_TYPE_INT32:
/* 32-bit integer */
for (yy = 0; yy < imOut->ysize; yy++) {
ss = 0.0;
for (x = (int) xmin; x < (int) xmax; x++)
ss = ss + IMAGING_PIXEL_I(imIn, x, yy) * k[x - (int) xmin];
IMAGING_PIXEL_I(imOut, xx, yy) = (int) ss * ww;
}
break;
case IMAGING_TYPE_FLOAT32:
/* 32-bit float */
for (yy = 0; yy < imOut->ysize; yy++) {
ss = 0.0;
for (x = (int) xmin; x < (int) xmax; x++)
ss = ss + IMAGING_PIXEL_F(imIn, x, yy) * k[x - (int) xmin];
IMAGING_PIXEL_F(imOut, xx, yy) = ss * ww;
}
break;
default:
ImagingSectionLeave(&cookie);
return (Imaging) ImagingError_ModeError();
}
}
}
ImagingSectionLeave(&cookie);
free(k);
return imOut;
}
ImagingHistogram
ImagingGetHistogram(Imaging im, Imaging imMask, void* minmax)
{
ImagingSectionCookie cookie;
int x, y, i;
ImagingHistogram h;
INT32 imin, imax;
FLOAT32 fmin, fmax, scale;
if (!im)
return ImagingError_ModeError();
if (imMask) {
/* Validate mask */
if (im->xsize != imMask->xsize || im->ysize != imMask->ysize)
return ImagingError_Mismatch();
if (strcmp(imMask->mode, "1") != 0 && strcmp(imMask->mode, "L") != 0)
return ImagingError_ValueError("bad transparency mask");
}
h = ImagingHistogramNew(im);
if (imMask) {
/* mask */
if (im->image8) {
ImagingSectionEnter(&cookie);
for (y = 0; y < im->ysize; y++)
for (x = 0; x < im->xsize; x++)
if (imMask->image8[y][x] != 0)
h->histogram[im->image8[y][x]]++;
ImagingSectionLeave(&cookie);
} else { /* yes, we need the braces. C isn't Python! */
if (im->type != IMAGING_TYPE_UINT8)
return ImagingError_ModeError();
ImagingSectionEnter(&cookie);
for (y = 0; y < im->ysize; y++) {
UINT8* in = (UINT8*) im->image32[y];
for (x = 0; x < im->xsize; x++)
if (imMask->image8[y][x] != 0) {
h->histogram[(*in++)]++;
h->histogram[(*in++)+256]++;
h->histogram[(*in++)+512]++;
h->histogram[(*in++)+768]++;
} else
in += 4;
}
ImagingSectionLeave(&cookie);
}
} else {
/* mask not given; process pixels in image */
if (im->image8) {
ImagingSectionEnter(&cookie);
for (y = 0; y < im->ysize; y++)
for (x = 0; x < im->xsize; x++)
h->histogram[im->image8[y][x]]++;
ImagingSectionLeave(&cookie);
} else {
switch (im->type) {
case IMAGING_TYPE_UINT8:
ImagingSectionEnter(&cookie);
for (y = 0; y < im->ysize; y++) {
UINT8* in = (UINT8*) im->image[y];
for (x = 0; x < im->xsize; x++) {
h->histogram[(*in++)]++;
h->histogram[(*in++)+256]++;
h->histogram[(*in++)+512]++;
h->histogram[(*in++)+768]++;
}
}
ImagingSectionLeave(&cookie);
break;
case IMAGING_TYPE_INT32:
if (!minmax)
return ImagingError_ValueError("min/max not given");
if (!im->xsize || !im->ysize)
break;
imin = ((INT32*) minmax)[0];
imax = ((INT32*) minmax)[1];
if (imin >= imax)
break;
ImagingSectionEnter(&cookie);
scale = 255.0F / (imax - imin);
for (y = 0; y < im->ysize; y++) {
INT32* in = im->image32[y];
for (x = 0; x < im->xsize; x++) {
i = (int) (((*in++)-imin)*scale);
if (i >= 0 && i < 256)
h->histogram[i]++;
}
}
ImagingSectionLeave(&cookie);
break;
case IMAGING_TYPE_FLOAT32:
if (!minmax)
return ImagingError_ValueError("min/max not given");
if (!im->xsize || !im->ysize)
break;
fmin = ((FLOAT32*) minmax)[0];
fmax = ((FLOAT32*) minmax)[1];
if (fmin >= fmax)
break;
ImagingSectionEnter(&cookie);
scale = 255.0F / (fmax - fmin);
for (y = 0; y < im->ysize; y++) {
FLOAT32* in = (FLOAT32*) im->image32[y];
for (x = 0; x < im->xsize; x++) {
i = (int) (((*in++)-fmin)*scale);
if (i >= 0 && i < 256)
h->histogram[i]++;
}
}
ImagingSectionLeave(&cookie);
break;
}
}
}
return h;
}