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set jpeg Q for pyramids carefully

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This commit is contained in:
John Cupitt 2008-02-15 15:06:31 +00:00
parent 1c6632a2be
commit 775f339360
3 changed files with 34 additions and 8 deletions
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1
ChangeLog
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@ -4,6 +4,7 @@
- add __str__ to VError in Python (thanks Ole)
- revert the dynamic wrapping for Python :-( next version!
- added VImage::convert2disc (thanks Ole)
- you can now set the jpeg quality factor for tiff pyramids (thanks Joe)
12/12/07 started 7.13.3
- added "include <cstring>" to VImage.cc to help gcc 4.3

12
TODO
View File

@ -1,6 +1,18 @@
- JPEG write should know about CMYK as well, maybe write all 4 band images as
CMYK?
- JPEG read could have a "subsample" param and use
unsigned int scale_num, scale_denom
Scale the image by the fraction scale_num/scale_denom.
Default is 1/1, or no scaling. Currently, the only supported
scaling ratios are 1/1, 1/2, 1/4, and 1/8. (The library design
allows for arbitrary scaling ratios but this is not likely to
be implemented any time soon.) Smaller scaling ratios permit
significantly faster decoding since fewer pixels need be processed
and a simpler IDCT method can be used.
- HAVE_HYPOT could define a hypot() macro?
- write our own python extension to call a vips operation by name

29
libsrc/conversion/im_vips2tiff.c
View File

@ -93,6 +93,9 @@
* - support TIFFTAG_PREDICTOR types for lzw and deflate compression
* 3/11/07
* - use im_wbuffer() for background writes
* 15/2/08
* - set TIFFTAG_JPEGQUALITY explicitly when we copy TIFF files, since
* libtiff doesn't keep this in the header (thanks Joe)
*/
/*
@ -1396,11 +1399,10 @@ make_tiff_write( IMAGE *im, const char *filename )
* we might have set.
*/
static int
tiff_copy( TIFF *out, TIFF *in )
tiff_copy( TiffWrite *tw, TIFF *out, TIFF *in )
{
uint32 i32, i32a;
uint16 i16;
int i;
float f;
tdata_t buf;
ttile_t tile;
@ -1412,11 +1414,18 @@ tiff_copy( TIFF *out, TIFF *in )
CopyField( TIFFTAG_IMAGELENGTH, i32 );
CopyField( TIFFTAG_PLANARCONFIG, i16 );
CopyField( TIFFTAG_ORIENTATION, i16 );
CopyField( TIFFTAG_COMPRESSION, i16 );
CopyField( TIFFTAG_XRESOLUTION, f );
CopyField( TIFFTAG_YRESOLUTION, f );
CopyField( TIFFTAG_RESOLUTIONUNIT, i16 );
CopyField( TIFFTAG_JPEGQUALITY, i );
CopyField( TIFFTAG_COMPRESSION, i16 );
if( i16 == COMPRESSION_JPEG ) {
/* For some reason the jpeg Q is always 75 :-( so we can't
* copy, we have to set explicitly.
int i;
CopyField( TIFFTAG_JPEGQUALITY, i );
*/
TIFFSetField( out, TIFFTAG_JPEGQUALITY, tw->jpqual );
}
CopyField( TIFFTAG_PREDICTOR, i16 );
CopyField( TIFFTAG_SAMPLESPERPIXEL, i16 );
CopyField( TIFFTAG_BITSPERSAMPLE, i16 );
@ -1433,6 +1442,10 @@ tiff_copy( TIFF *out, TIFF *in )
for( tile = 0; tile < n; tile++ ) {
tsize_t len;
/* It'd be good to use * TIFFReadRawTile()/TIFFWriteRawTile()
* here to save compression/decompression, but sadly it seems
* not to work :-( investigate at some point.
*/
len = TIFFReadEncodedTile( in, tile, buf, (tsize_t) -1 );
if( len < 0 ||
TIFFWriteEncodedTile( out, tile, buf, len ) < 0 ) {
@ -1448,14 +1461,14 @@ tiff_copy( TIFF *out, TIFF *in )
/* Append a file to a TIFF file.
*/
static int
tiff_append( TIFF *out, const char *name )
tiff_append( TiffWrite *tw, TIFF *out, const char *name )
{
TIFF *in;
if( !(in = tiff_openin( name )) )
return( -1 );
if( tiff_copy( out, in ) ) {
if( tiff_copy( tw, out, in ) ) {
TIFFClose( in );
return( -1 );
}
@ -1482,13 +1495,13 @@ gather_pyramid( TiffWrite *tw )
if( !(out = tiff_openout( tw->name )) )
return( -1 );
if( tiff_append( out, tw->bname ) ) {
if( tiff_append( tw, out, tw->bname ) ) {
TIFFClose( out );
return( -1 );
}
for( layer = tw->layer; layer; layer = layer->below )
if( tiff_append( out, layer->lname ) ) {
if( tiff_append( tw, out, layer->lname ) ) {
TIFFClose( out );
return( -1 );
}