From 7deead8911c84a3a45f82a7eef9bf69d6290b32b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 13 May 2020 12:45:28 +0100
Subject: [PATCH] add a subifd flag to tiffsave

---
 libvips/foreign/pforeign.h  |  6 ++++--
 libvips/foreign/tiffsave.c  | 25 ++++++++++++++++++++++---
 libvips/foreign/vips2tiff.c |  9 ++++++---
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/libvips/foreign/pforeign.h b/libvips/foreign/pforeign.h
index 92b32cc4..c6d3b49d 100644
--- a/libvips/foreign/pforeign.h
+++ b/libvips/foreign/pforeign.h
@@ -63,7 +63,8 @@ int vips__tiff_write( VipsImage *in, const char *filename,
 	VipsRegionShrink region_shrink,
 	int level, 
 	gboolean lossless,
-	VipsForeignDzDepth depth );
+	VipsForeignDzDepth depth,
+	gboolean subifd );
 
 int vips__tiff_write_buf( VipsImage *in, 
 	void **obuf, size_t *olen, 
@@ -81,7 +82,8 @@ int vips__tiff_write_buf( VipsImage *in,
 	VipsRegionShrink region_shrink,
 	int level, 
 	gboolean lossless,
-	VipsForeignDzDepth depth );
+	VipsForeignDzDepth depth,
+	gboolean subifd );
 
 gboolean vips__istiff_source( VipsSource *source );
 gboolean vips__istifftiled_source( VipsSource *source );
diff --git a/libvips/foreign/tiffsave.c b/libvips/foreign/tiffsave.c
index 8644a820..b66ce998 100644
--- a/libvips/foreign/tiffsave.c
+++ b/libvips/foreign/tiffsave.c
@@ -21,6 +21,8 @@
  * 	- xres/yres params were in pixels/cm
  * 26/1/20
  * 	- add "depth" to set pyr depth
+ * 12/5/20
+ * 	- add "subifd" to create pyr layers as sub-directories
  */
 
 /*
@@ -98,6 +100,8 @@ typedef struct _VipsForeignSaveTiff {
 	int level;
 	gboolean lossless;
 	VipsForeignDzDepth depth;
+	gboolean subifd;
+
 } VipsForeignSaveTiff;
 
 typedef VipsForeignSaveClass VipsForeignSaveTiffClass;
@@ -327,7 +331,7 @@ vips_foreign_save_tiff_class_init( VipsForeignSaveTiffClass *class )
 		1, 22, 10 );
 
 	VIPS_ARG_BOOL( class, "lossless", 24, 
-		_( "lossless" ), 
+		_( "Lossless" ), 
 		_( "Enable WEBP lossless mode" ),
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsForeignSaveTiff, lossless ),
@@ -340,6 +344,13 @@ vips_foreign_save_tiff_class_init( VipsForeignSaveTiffClass *class )
 		G_STRUCT_OFFSET( VipsForeignSaveTiff, depth ),
 		VIPS_TYPE_FOREIGN_DZ_DEPTH, VIPS_FOREIGN_DZ_DEPTH_ONETILE ); 
 
+	VIPS_ARG_BOOL( class, "subifd", 24, 
+		_( "Sub-IFD" ), 
+		_( "Save pyr layers as sub-IFDs" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveTiff, subifd ),
+		FALSE );
+
 }
 
 static void
@@ -396,7 +407,8 @@ vips_foreign_save_tiff_file_build( VipsObject *object )
 		tiff->region_shrink,
 		tiff->level,
 		tiff->lossless,
-		tiff->depth ) )
+		tiff->depth,
+		tiff->subifd ) )
 		return( -1 );
 
 	return( 0 );
@@ -468,7 +480,8 @@ vips_foreign_save_tiff_buffer_build( VipsObject *object )
 		tiff->region_shrink,
 		tiff->level,
 		tiff->lossless, 
-		tiff->depth ) )
+		tiff->depth,
+		tiff->subifd ) )
 		return( -1 );
 
 	/* vips__tiff_write_buf() makes a buffer that needs g_free(), not
@@ -537,6 +550,7 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * * @level: %gint, Zstd compression level
  * * @lossless: %gboolean, WebP losssless mode
  * * @depth: #VipsForeignDzDepth how deep to make the pyramid
+ * * @subifd: %gboolean write pyr layers as sub-ifds
  *
  * Write a VIPS image to a file as TIFF.
  *
@@ -620,6 +634,10 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * #VIPS_META_PHOTOSHOP_NAME (if set) is used to set the value of the PHOTOSHOP
  * tag.
  *
+ * By default, pyramid layers are saved as consecutive pages. 
+ * Set @subifd to save pyramid layers as sub-directories of the main image.
+ * Setting this option can improve compatibility with formats like OME.
+ *
  * See also: vips_tiffload(), vips_image_write_to_file().
  *
  * Returns: 0 on success, -1 on error.
@@ -665,6 +683,7 @@ vips_tiffsave( VipsImage *in, const char *filename, ... )
  * * @level: %gint, Zstd compression level
  * * @lossless: %gboolean, WebP losssless mode
  * * @depth: #VipsForeignDzDepth how deep to make the pyramid
+ * * @subifd: %gboolean write pyr layers as sub-ifds
  *
  * As vips_tiffsave(), but save to a memory buffer. 
  *
diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index c2c46854..24c3ad16 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -334,6 +334,7 @@ struct _Wtiff {
 	int level;			/* zstd compression level */
 	gboolean lossless;		/* webp lossless mode */
 	VipsForeignDzDepth depth;	/* Pyr depth */
+	gboolean subifd;		/* Write pyr layers into subifds */
 
 	/* True if we've detected a toilet-roll image, plus the page height,
 	 * which has been checked to be a factor of im->Ysize. page_number
@@ -1858,7 +1859,7 @@ wtiff_copy_tiff( Wtiff *wtiff, TIFF *out, TIFF *in )
 	return( 0 );
 }
 
-/* Append all of the lower layers we wrote to the output.
+/* Append all of the layers we wrote to the output.
  */
 static int
 wtiff_gather( Wtiff *wtiff )
@@ -1999,7 +2000,8 @@ vips__tiff_write( VipsImage *input, const char *filename,
 	VipsRegionShrink region_shrink,
 	int level, 
 	gboolean lossless,
-	VipsForeignDzDepth depth )
+	VipsForeignDzDepth depth,
+	gboolean subifd )
 {
 	Wtiff *wtiff;
 
@@ -2043,7 +2045,8 @@ vips__tiff_write_buf( VipsImage *input,
 	VipsRegionShrink region_shrink,
 	int level, 
 	gboolean lossless,
-	VipsForeignDzDepth depth )
+	VipsForeignDzDepth depth,
+	gboolean subifd )
 {
 	Wtiff *wtiff;