From f65f9088f6b9c2470d6cd377000ddc7842c45022 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 2 Jun 2012 17:42:42 +0100
Subject: [PATCH] make jpeg pyr write work with tiff4

there was a problem with sizing tiles in chrominance subsample mode
---
 ChangeLog                   |  1 +
 libvips/foreign/vips2tiff.c | 25 +++++++++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 9c0f6df7..c94f9afa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,7 @@
 - better resolution unit handling in deprecated im_vips2tiff()
 - use TIFF_CFLAGS output from pkg-config (thanks Jay)
 - much faster vips_argument_map()
+- make jpeg pyramids work with tiff4
 
 19/4/12 started 7.28.5
 - ifthenelse blend mode was broken
diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index 059d2bd5..ddec2f5f 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -126,6 +126,9 @@
  * 2/12/11
  * 	- make into a simple function call ready to be wrapped as a new-style
  * 	  VipsForeign class
+ * 2/6/12
+ * 	- copy jpeg pyramid in gather in RGB mode ... tiff4 doesn't do ycbcr
+ * 	  mode
  */
 
 /*
@@ -904,7 +907,8 @@ shrink_region( VipsRegion *from, VipsRect *area,
 /* Write a tile from a layer.
  */
 static int
-save_tile( TiffWrite *tw, TIFF *tif, VipsPel *tbuf, VipsRegion *reg, VipsRect *area )
+save_tile( TiffWrite *tw, 
+	TIFF *tif, VipsPel *tbuf, VipsRegion *reg, VipsRect *area )
 {
 	/* Have to repack pixels.
 	 */
@@ -1340,9 +1344,21 @@ tiff_copy( TiffWrite *tw, TIFF *out, TIFF *in )
 	/* TIFFTAG_JPEGQUALITY is a pesudo-tag, so we can't copy it.
 	 * Set explicitly from TiffWrite.
 	 */
-	if( tw->compression == COMPRESSION_JPEG ) 
+	if( tw->compression == COMPRESSION_JPEG ) {
 		TIFFSetField( out, TIFFTAG_JPEGQUALITY, tw->jpqual );
 
+		/* Enable rgb->ycbcr conversion in the jpeg write. See also
+		 * the photometric selection below.
+		 */
+		TIFFSetField( out, TIFFTAG_JPEGCOLORMODE, JPEGCOLORMODE_RGB );
+
+		/* And we want ycbcr expanded to rgb on read. Otherwise
+		 * TIFFTileSize() will give us the size of a chrominance
+		 * subsampled tile.
+		 */
+		TIFFSetField( in, TIFFTAG_JPEGCOLORMODE, JPEGCOLORMODE_RGB );
+	}
+
 	/* We can't copy profiles :( Set again from TiffWrite.
 	 */
 	if( embed_profile( tw, out ) )
@@ -1357,7 +1373,7 @@ tiff_copy( TiffWrite *tw, TIFF *out, TIFF *in )
 		 * here to save compression/decompression, but sadly it seems
 		 * not to work :-( investigate at some point.
 		 */
-		len = TIFFReadEncodedTile( in, tile, buf, (tsize_t) -1 );
+		len = TIFFReadEncodedTile( in, tile, buf, -1 );
 		if( len < 0 ||
 			TIFFWriteEncodedTile( out, tile, buf, len ) < 0 ) {
 			vips_free( buf );
@@ -1525,7 +1541,8 @@ vips__tiff_write( VipsImage *in, const char *filename,
 
 	/* Gather layers together into final pyramid file.
 	 */
-	if( tw->pyramid && gather_pyramid( tw ) ) {
+	if( tw->pyramid && 
+		gather_pyramid( tw ) ) {
 		free_tiff_write( tw );
 		return( -1 );
 	}