void
ImagingResampleHorizontal_32bpc(Imaging imOut, Imaging imIn, int offset,
int ksize, int *bounds, double *kk)
{
ImagingSectionCookie cookie;
double ss;
int xx, yy, x, xmin, xmax;
double *k;
ImagingSectionEnter(&cookie);
switch(imIn->type) {
case IMAGING_TYPE_INT32:
for (yy = 0; yy < imOut->ysize; yy++) {
for (xx = 0; xx < imOut->xsize; xx++) {
xmin = bounds[xx * 2 + 0];
xmax = bounds[xx * 2 + 1];
k = &kk[xx * ksize];
ss = 0.0;
for (x = 0; x < xmax; x++)
ss += IMAGING_PIXEL_I(imIn, x + xmin, yy + offset) * k[x];
IMAGING_PIXEL_I(imOut, xx, yy) = ROUND_UP(ss);
}
}
break;
case IMAGING_TYPE_FLOAT32:
for (yy = 0; yy < imOut->ysize; yy++) {
for (xx = 0; xx < imOut->xsize; xx++) {
xmin = bounds[xx * 2 + 0];
xmax = bounds[xx * 2 + 1];
k = &kk[xx * ksize];
ss = 0.0;
for (x = 0; x < xmax; x++)
ss += IMAGING_PIXEL_F(imIn, x + xmin, yy + offset) * k[x];
IMAGING_PIXEL_F(imOut, xx, yy) = ss;
}
}
break;
}
ImagingSectionLeave(&cookie);
}
void
ImagingResampleVertical_32bpc(Imaging imOut, Imaging imIn, int offset,
int ksize, int *bounds, double *kk)
{
ImagingSectionCookie cookie;
double ss;
int xx, yy, y, ymin, ymax;
double *k;
ImagingSectionEnter(&cookie);
switch(imIn->type) {
case IMAGING_TYPE_INT32:
for (yy = 0; yy < imOut->ysize; yy++) {
ymin = bounds[yy * 2 + 0];
ymax = bounds[yy * 2 + 1];
k = &kk[yy * ksize];
for (xx = 0; xx < imOut->xsize; xx++) {
ss = 0.0;
for (y = 0; y < ymax; y++)
ss += IMAGING_PIXEL_I(imIn, xx, y + ymin) * k[y];
IMAGING_PIXEL_I(imOut, xx, yy) = ROUND_UP(ss);
}
}
break;
case IMAGING_TYPE_FLOAT32:
for (yy = 0; yy < imOut->ysize; yy++) {
ymin = bounds[yy * 2 + 0];
ymax = bounds[yy * 2 + 1];
k = &kk[yy * ksize];
for (xx = 0; xx < imOut->xsize; xx++) {
ss = 0.0;
for (y = 0; y < ymax; y++)
ss += IMAGING_PIXEL_F(imIn, xx, y + ymin) * k[y];
IMAGING_PIXEL_F(imOut, xx, yy) = ss;
}
}
break;
}
ImagingSectionLeave(&cookie);
}
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;
}