/*
* Construct a mapping table to convert from the range
* of the data samples to [0,255] --for display. This
* process also handles inverting B&W images when needed.
*/
static int
setupMap(TIFFRGBAImage* img)
{
int32 x, range;
range = (int32)((1L<<img->bitspersample)-1);
img->Map = (TIFFRGBValue*) _TIFFmalloc((range+1) * sizeof (TIFFRGBValue));
if (img->Map == NULL) {
TIFFError(TIFFFileName(img->tif),
"No space for photometric conversion table");
return (0);
}
if (img->photometric == PHOTOMETRIC_MINISWHITE) {
for (x = 0; x <= range; x++)
img->Map[x] = ((range - x) * 255) / range;
} else {
for (x = 0; x <= range; x++)
img->Map[x] = (x * 255) / range;
}
if (img->bitspersample <= 8 &&
(img->photometric == PHOTOMETRIC_MINISBLACK ||
img->photometric == PHOTOMETRIC_MINISWHITE)) {
/*
* Use photometric mapping table to construct
* unpacking tables for samples <= 8 bits.
*/
if (!makebwmap(img))
return (0);
/* no longer need Map, free it */
_TIFFfree(img->Map), img->Map = NULL;
}
return (1);
}
boolean TIFFRasterImpl::gt(u_long w, u_long h) {
u_short minsamplevalue;
u_short maxsamplevalue;
u_short planarconfig;
RGBvalue* Map = nil;
if (!TIFFGetField(tif_, TIFFTAG_MINSAMPLEVALUE, &minsamplevalue)) {
minsamplevalue = 0;
}
if (!TIFFGetField(tif_, TIFFTAG_MAXSAMPLEVALUE, &maxsamplevalue)) {
maxsamplevalue = (1<<bitspersample_)-1;
}
switch (photometric_) {
case PHOTOMETRIC_RGB:
if (minsamplevalue == 0 && maxsamplevalue == 255) {
break;
}
/* fall thru... */
case PHOTOMETRIC_MINISBLACK:
case PHOTOMETRIC_MINISWHITE: {
register int x, range;
range = maxsamplevalue - minsamplevalue;
Map = new RGBvalue[range + 1];
if (Map == nil) {
TIFFError(
TIFFFileName(tif_),
"No space for photometric conversion table"
);
return false;
}
if (photometric_ == PHOTOMETRIC_MINISWHITE) {
for (x = 0; x <= range; x++) {
Map[x] = ((range - x) * 255) / range;
}
} else {
for (x = 0; x <= range; x++) {
Map[x] = (x * 255) / range;
}
}
if (photometric_ != PHOTOMETRIC_RGB && bitspersample_ != 8) {
/*
* Use photometric mapping table to construct
* unpacking tables for samples < 8 bits.
*/
if (!makebwmap(Map)) {
return false;
}
delete Map; /* no longer need Map, free it */
Map = nil;
}
break;
}
case PHOTOMETRIC_PALETTE:
if (!TIFFGetField(
tif_, TIFFTAG_COLORMAP, &redcmap_, &greencmap_, &bluecmap_)
) {
TIFFError(TIFFFileName(tif_), "Missing required \"Colormap\" tag");
return (false);
}
/*
* Convert 16-bit colormap to 8-bit (unless it looks
* like an old-style 8-bit colormap).
*/
if (
checkcmap(
1 << bitspersample_, redcmap_, greencmap_, bluecmap_
) == 16
) {
int i;
for (i = (1 << bitspersample_) - 1; i > 0; i--) {
#define CVT(x) (((x) * 255) / ((1L<<16)-1))
redcmap_[i] = (u_short) CVT(redcmap_[i]);
greencmap_[i] = (u_short) CVT(greencmap_[i]);
bluecmap_[i] = (u_short) CVT(bluecmap_[i]);
}
}
if (bitspersample_ <= 8) {
/*
* Use mapping table and colormap to construct
* unpacking tables for samples < 8 bits.
*/
if (!makecmap(redcmap_, greencmap_, bluecmap_)) {
return false;
}
}
break;
}
TIFFGetField(tif_, TIFFTAG_PLANARCONFIG, &planarconfig);
boolean e;
if (planarconfig == PLANARCONFIG_SEPARATE && samplesperpixel_ > 1) {
e = TIFFIsTiled(tif_) ?
gtTileSeparate(Map, h, w) : gtStripSeparate(Map, h, w);
} else {
e = TIFFIsTiled(tif_) ?
gtTileContig(Map, h, w) : gtStripContig(Map, h, w);
}
delete Map;
return e;
}