Merge pull request #1672 from MathemanFlo/master

Added write functionality for 2 and 4 bit tiff

libvips/foreign/pforeign.h

@@ -53,7 +53,7 @@ int vips__tiff_write( VipsImage *in, const char *filename,
 	char *profile,
 	gboolean tile, int tile_width, int tile_height,
 	gboolean pyramid,
-	gboolean squash,
+	int bitdepth,
 	gboolean miniswhite,
 	VipsForeignTiffResunit resunit, double xres, double yres,
 	gboolean bigtiff,
@@ -73,7 +73,7 @@ int vips__tiff_write_buf( VipsImage *in,
 	char *profile,
 	gboolean tile, int tile_width, int tile_height,
 	gboolean pyramid,
-	gboolean squash,
+	int bitdepth,
 	gboolean miniswhite,
 	VipsForeignTiffResunit resunit, double xres, double yres,
 	gboolean bigtiff,

libvips/foreign/tiff2vips.c

@@ -199,6 +199,8 @@
  * 	- better handling of aligned reads in multipage tiffs
  * 28/5/20
  * 	- add subifd
+ * 06/6/20
+ *  - add load functionality for 2 and 4 bit greyscale tiffs
  */
 
 /*
@@ -1056,6 +1058,78 @@ rtiff_onebit_line( Rtiff *rtiff, VipsPel *q, VipsPel *p, int n, void *flg )
 	}
 }
 
+/* Per-scanline process function for 2 bit greyscale images.
+ */
+static void
+rtiff_twobit_line( Rtiff *rtiff, VipsPel *q, VipsPel *p, int n, void *flg )
+{
+	int x, i, z;
+	int minisblack = 
+		rtiff->header.photometric_interpretation == PHOTOMETRIC_MINISBLACK;
+	VipsPel twobits, fourbits, bits;
+
+	x = 0;
+	for( i = 0; i < (n >> 2); i++ ) {
+		bits = (VipsPel) minisblack ? p[i] : ~p[i];
+
+		for( z = 0; z < 4; z++ ) {
+			/* The grey shade is the value four times concatenated */
+			twobits = bits >> 6;
+			fourbits = twobits | (twobits << 2);
+			q[x] = fourbits | (fourbits << 4);
+			bits <<= 2;
+			x += 1;
+		}
+	}
+
+	/* Do last byte in line.
+	*/
+	if( n & 3 ) {
+		bits = (VipsPel) minisblack ? p[i] : ~p[i];
+		for( z = 0; z < (n & 3) ; z++ ) {
+			twobits = bits >> 6;
+			fourbits = twobits | (twobits << 2);
+			q[x + z] = fourbits | (fourbits << 4);
+			bits <<= 2;
+		}
+	}
+}
+
+/* Per-scanline process function for 4 bit greyscale images.
+ */
+static void
+rtiff_fourbit_line( Rtiff *rtiff, VipsPel *q, VipsPel *p, int n, void *flg )
+{
+	int x, i, z;
+	int minisblack = 
+		rtiff->header.photometric_interpretation == PHOTOMETRIC_MINISBLACK;
+	VipsPel bits;
+
+	x = 0;
+
+	for( i = 0; i < (n >> 1); i++ ) {
+		bits = (VipsPel) minisblack ? p[i] : ~p[i];
+
+		for( z = 0; z < 2; z++ ) {
+			/* The grey shade is the value two times concatenated */
+			q[x] = (bits & 0xF0) | (bits >> 4);
+			bits <<= 4;
+			x += 1;
+		}
+	}
+
+	/* Do last byte in line.
+	*/
+	if( n & 1) {
+		bits = (VipsPel) minisblack ? p[i] : ~p[i];
+		for( z = 0; z < (n & 1) ; z++ ) {
+			q[x + z] = (bits & 0xF0) | (bits >> 4);
+			bits <<= 4;
+		}
+	}
+}
+
+
 /* Read a 1-bit TIFF image. 
  */
 static int
@@ -1075,6 +1149,44 @@ rtiff_parse_onebit( Rtiff *rtiff, VipsImage *out )
 	return( 0 );
 }
 
+/* Read a 2-bit TIFF image. 
+ */
+static int
+rtiff_parse_twobit( Rtiff *rtiff, VipsImage *out )
+{
+	if( rtiff_check_samples( rtiff, 1 ) ||
+		rtiff_check_bits( rtiff, 2 ) )
+		return( -1 );
+
+	out->Bands = 1; 
+	out->BandFmt = VIPS_FORMAT_UCHAR; 
+	out->Coding = VIPS_CODING_NONE; 
+	out->Type = VIPS_INTERPRETATION_B_W; 
+
+	rtiff->sfn = rtiff_twobit_line;
+
+	return( 0 );
+}
+
+/* Read a 4-bit TIFF image. 
+ */
+static int
+rtiff_parse_fourbit( Rtiff *rtiff, VipsImage *out )
+{
+	if( rtiff_check_samples( rtiff, 1 ) ||
+		rtiff_check_bits( rtiff, 4 ) )
+		return( -1 );
+
+	out->Bands = 1; 
+	out->BandFmt = VIPS_FORMAT_UCHAR; 
+	out->Coding = VIPS_CODING_NONE; 
+	out->Type = VIPS_INTERPRETATION_B_W; 
+
+	rtiff->sfn = rtiff_fourbit_line;
+
+	return( 0 );
+}
+
 /* Swap the sense of the first channel, if necessary. 
  */
 #define GREY_LOOP( TYPE, MAX ) { \
@@ -1517,8 +1629,13 @@ rtiff_pick_reader( Rtiff *rtiff )
 
 	if( photometric_interpretation == PHOTOMETRIC_MINISWHITE ||
 		photometric_interpretation == PHOTOMETRIC_MINISBLACK ) {
-		if( bits_per_sample == 1 )
+
-			return( rtiff_parse_onebit ); 
+		if( bits_per_sample == 1)
+			return ( rtiff_parse_onebit );
+		else if ( bits_per_sample == 2 )
+			return ( rtiff_parse_twobit);
+		else if ( bits_per_sample == 4 )
+			return ( rtiff_parse_fourbit);
 		else
 			return( rtiff_parse_greyscale ); 
 	}

libvips/foreign/tiffsave.c

@@ -23,6 +23,8 @@
  * 	- add "depth" to set pyr depth
  * 12/5/20
  * 	- add "subifd" to create pyr layers as sub-directories
+ * 8/6/20
+ * 	- add bitdepth support for 2 and 4 bit greyscale images
  */
 
 /*
@@ -89,6 +91,7 @@ typedef struct _VipsForeignSaveTiff {
 	int tile_height;
 	gboolean pyramid;
 	gboolean squash;
+	int bitdepth;
 	gboolean miniswhite;
 	VipsForeignTiffResunit resunit;
 	double xres;
@@ -263,9 +266,16 @@ vips_foreign_save_tiff_class_init( VipsForeignSaveTiffClass *class )
 	VIPS_ARG_BOOL( class, "squash", 14, 
 		_( "Squash" ), 
 		_( "Squash images down to 1 bit" ),
-		VIPS_ARGUMENT_OPTIONAL_INPUT,
+        VIPS_ARGUMENT_OPTIONAL_INPUT | VIPS_ARGUMENT_DEPRECATED,
 		G_STRUCT_OFFSET( VipsForeignSaveTiff, squash ),
 		FALSE );
+	
+	VIPS_ARG_INT( class, "bitdepth", 14,
+		_( "bitdepth" ),
+		_( "Change greyscale image bit depth to 1,2, 4 or 8." ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveTiff, bitdepth ),
+		1,8,8 );
 
 	VIPS_ARG_BOOL( class, "miniswhite", 14, 
 		_( "Miniswhite" ), 
@@ -368,6 +378,7 @@ vips_foreign_save_tiff_init( VipsForeignSaveTiff *tiff )
 	tiff->level = 10;
 	tiff->lossless = FALSE;
 	tiff->depth = VIPS_FOREIGN_DZ_DEPTH_ONETILE; 
+	tiff->bitdepth = 0;
 }
 
 typedef struct _VipsForeignSaveTiffFile {
@@ -392,12 +403,17 @@ vips_foreign_save_tiff_file_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
+        /* handle the deprecated squash parameter */
+        if( vips_object_argument_isset(object,"squash") ) {
+            tiff->bitdepth = 1; /*we set that even in the case of LAB to LABQ */
+        }
+
 	if( vips__tiff_write( save->ready, file->filename,
 		tiff->compression, tiff->Q, tiff->predictor,
 		tiff->profile,
 		tiff->tile, tiff->tile_width, tiff->tile_height,
 		tiff->pyramid,
-		tiff->squash,
+		tiff->bitdepth,
 		tiff->miniswhite,
 		tiff->resunit, tiff->xres, tiff->yres,
 		tiff->bigtiff,
@@ -470,7 +486,7 @@ vips_foreign_save_tiff_buffer_build( VipsObject *object )
 		tiff->profile,
 		tiff->tile, tiff->tile_width, tiff->tile_height,
 		tiff->pyramid,
-		tiff->squash,
+		tiff->bitdepth,
 		tiff->miniswhite,
 		tiff->resunit, tiff->xres, tiff->yres,
 		tiff->bigtiff,
@@ -540,6 +556,7 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * * @tile_height: %gint for tile size
  * * @pyramid: %gboolean, write an image pyramid
  * * @squash: %gboolean, squash 8-bit images down to 1 bit
+ * * @bitdepth: %int, change bit depth to 1,2, or 4 bit
  * * @miniswhite: %gboolean, write 1-bit images as MINISWHITE
  * * @resunit: #VipsForeignTiffResunit for resolution unit
  * * @xres: %gdouble horizontal resolution in pixels/mm
@@ -605,10 +622,25 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * MINISBLACK TIFFs where black is a 0 bit, but if you set @miniswhite, it
  * will use 0 for a white bit. Many pre-press applications only work with
  * images which use this sense. @miniswhite only affects one-bit images, it
- * does nothing for greyscale images. 
+ * does nothing for greyscale images. Consider @bitdepth for depths 1, 2 and 4.
  *
  * Set @squash to squash 3-band float CIELAB images down to 8-bit CIELAB.
  *
+ * Set @bitdepth to make 8-bit uchar images write as 1,2 or 4-bit TIFFs.
+ * In case of depth 1: Values >128 are written as white, values <=128 as black.
+ * Normally vips will write MINISBLACK TIFFs where black is a 0 bit, but if you
+ * set @miniswhite, it will use 0 for a white bit. Many pre-press applications
+ * only work with images which use this sense. @miniswhite only affects one-bit
+ * images, it does nothing for greyscale images.
+ * In case of depth 2: The same holds but values < 64 are written as black.
+ * For 64 <= values < 128 they are written as dark grey, for 128 <= values < 192
+ * they are written as light gray and values above are written as white.
+ * In case @miniswhite is set to true this behavior is inverted.
+ * In case of depth 4: values < 16 are written as black, and so on for the
+ * lighter shades. In case @miniswhite is set to true this behavior is inverted.
+ * 
+ * Set @bitdepth to 8 to squash 3-band float CIELAB images down to 8-bit CIELAB.
+ *
  * Use @resunit to override the default resolution unit.  
  * The default 
  * resolution unit is taken from the header field 
@@ -673,6 +705,7 @@ vips_tiffsave( VipsImage *in, const char *filename, ... )
  * * @tile_height: %gint for tile size
  * * @pyramid: %gboolean, write an image pyramid
  * * @squash: %gboolean, squash 8-bit images down to 1 bit
+ * * @bitdepth: %int, change bit depth to 1,2 or 4-bit or squash float to 8 bit
  * * @miniswhite: %gboolean, write 1-bit images as MINISWHITE
  * * @resunit: #VipsForeignTiffResunit for resolution unit
  * * @xres: %gdouble horizontal resolution in pixels/mm

libvips/foreign/vips2tiff.c

@@ -195,8 +195,9 @@
  * 	- add PAGENUMBER support
  * 23/5/20
  * 	- add support for subifd pyramid layers
+ * 8/6/20
+ * 	- add bitdepth support for 2 and 4 bit greyscale images
  */
-
 /*
 
     This file is part of VIPS.
@@ -337,7 +338,7 @@ struct _Wtiff {
 	int tile;			/* Tile or not */
 	int tilew, tileh;		/* Tile size */
 	int pyramid;			/* Wtiff pyramid */
-	int squash;			/* Write as small format */
+	int bitdepth;                   /* Write as 1, 2 or 4 bit */
 	int miniswhite;			/* Wtiff as 0 == white */
         int resunit;                    /* Resolution unit (inches or cm) */
         double xres;                   	/* Resolution in X */
@@ -694,13 +695,14 @@ wtiff_write_header( Wtiff *wtiff, Layer *layer )
 		TIFFSetField( tif, TIFFTAG_BITSPERSAMPLE, 8 );
 		TIFFSetField( tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_CIELAB );
 	}
-	else if( wtiff->squash ) {
+	else if( wtiff->bitdepth == 1 || wtiff->bitdepth == 2 ||
+                 wtiff->bitdepth == 4 ) {
 		TIFFSetField( tif, TIFFTAG_SAMPLESPERPIXEL, 1 );
-		TIFFSetField( tif, TIFFTAG_BITSPERSAMPLE, 1 );
+		TIFFSetField( tif, TIFFTAG_BITSPERSAMPLE, wtiff->bitdepth );
-		TIFFSetField( tif, TIFFTAG_PHOTOMETRIC, 
+		TIFFSetField( tif, TIFFTAG_PHOTOMETRIC,
-			wtiff->miniswhite ? 
+			wtiff->miniswhite ?
-				PHOTOMETRIC_MINISWHITE :  
+				PHOTOMETRIC_MINISWHITE :
-				PHOTOMETRIC_MINISBLACK ); 
+				PHOTOMETRIC_MINISBLACK );
 	}
 	else {
 		int photometric;
@@ -1039,13 +1041,13 @@ ready_to_write( Wtiff *wtiff )
 
 	/* "squash" float LAB down to LABQ.
 	 */
-	if( wtiff->squash &&
+	if( wtiff->bitdepth &&
 		wtiff->input->Bands == 3 &&
 		wtiff->input->BandFmt == VIPS_FORMAT_FLOAT &&
 		wtiff->input->Type == VIPS_INTERPRETATION_LAB ) {
 		if( vips_Lab2LabQ( wtiff->input, &wtiff->ready, NULL ) )
 			return( -1 );
-		wtiff->squash = 0;
+		wtiff->bitdepth = 0;
 	}
 	else {
 		wtiff->ready = wtiff->input;
@@ -1062,7 +1064,7 @@ wtiff_new( VipsImage *input, const char *filename,
 	char *profile,
 	gboolean tile, int tile_width, int tile_height,
 	gboolean pyramid,
-	gboolean squash,
+	int bitdepth,
 	gboolean miniswhite,
 	VipsForeignTiffResunit resunit, double xres, double yres,
 	gboolean bigtiff,
@@ -1091,7 +1093,7 @@ wtiff_new( VipsImage *input, const char *filename,
 	wtiff->tilew = tile_width;
 	wtiff->tileh = tile_height;
 	wtiff->pyramid = pyramid;
-	wtiff->squash = squash;
+	wtiff->bitdepth = bitdepth;
 	wtiff->miniswhite = miniswhite;
 	wtiff->resunit = get_resunit( resunit );
 	wtiff->xres = xres;
@@ -1188,23 +1190,30 @@ wtiff_new( VipsImage *input, const char *filename,
 		}
 	}
 
-	/* Can only squash 8 bit mono. 3-band float should have been squashed
+	if( wtiff->bitdepth && !(wtiff->bitdepth == 1 || wtiff->bitdepth == 2 
-	 * above.
+		|| wtiff->bitdepth == 4) ) {
+			g_warning( "%s",
+                _( "allows only bitdepth values 1,2 or 4. "
+					"-- disabling bitdepth") );
+            wtiff->bitdepth = 0;
+	}
+	
+    /* Can only have byte fractional bit depths for 8 bit mono.
+     * 3-band float should have been packed above.
 	 */
-	if( wtiff->squash &&
+	if( wtiff->bitdepth && !(wtiff->ready->Coding == VIPS_CODING_NONE &&
-		!(wtiff->ready->Coding == VIPS_CODING_NONE && 
+		wtiff->ready->BandFmt == VIPS_FORMAT_UCHAR && 
-			wtiff->ready->BandFmt == VIPS_FORMAT_UCHAR &&
+		wtiff->ready->Bands == 1) ) { 
-			wtiff->ready->Bands == 1) ) { 
 		g_warning( "%s",
-			_( "can only squash 1-band uchar and "
+                ( "can only set bitdepth for 1-band uchar and "
-				"3-band float lab -- disabling squash" ) );
+                        "3-band float lab -- disabling bitdepth" ) );
-		wtiff->squash = 0;
+        wtiff->bitdepth = 0;
 	}
 
-	if( wtiff->squash && 
+    if( wtiff->bitdepth &&
 		wtiff->compression == COMPRESSION_JPEG ) {
 		g_warning( "%s", 
-			_( "can't have 1-bit JPEG -- disabling JPEG" ) );
+            _( "can't have 1,2 or 4-bit JPEG -- disabling JPEG" ) );
 		wtiff->compression = COMPRESSION_NONE;
 	}
  
@@ -1239,8 +1248,12 @@ wtiff_new( VipsImage *input, const char *filename,
 	 */
 	if( wtiff->ready->Coding == VIPS_CODING_LABQ )
 		wtiff->tls = wtiff->tilew * 3;
-	else if( wtiff->squash )
+	else if( wtiff->bitdepth == 1 )
 		wtiff->tls = VIPS_ROUND_UP( wtiff->tilew, 8 ) / 8;
+	else if( wtiff->bitdepth == 2 )
+		wtiff->tls = VIPS_ROUND_UP( wtiff->tilew, 4 ) / 4;
+	else if( wtiff->bitdepth == 4 )
+		wtiff->tls = VIPS_ROUND_UP( wtiff->tilew, 2 ) / 2;
 	else
 		wtiff->tls = VIPS_IMAGE_SIZEOF_PEL( wtiff->ready ) * 
 			wtiff->tilew;
@@ -1300,6 +1313,60 @@ eightbit2onebit( Wtiff *wtiff, VipsPel *q, VipsPel *p, int n )
 		*q++ = bits << (8 - (x & 0x7));
 }
 
+/* Pack 8 bit VIPS to 2 bit TIFF.
+ */
+static void
+eightbit2twobit( Wtiff *wtiff, VipsPel *q, VipsPel *p, int n )
+{
+	int x;
+	VipsPel bits;
+	VipsPel mask = wtiff->miniswhite ? 3 : 0;
+
+	bits = 0;
+	
+	for( x = 0; x < n; x++ ) {
+		bits <<= 2;
+		bits |= (p[x] >> 6) ^ mask;
+
+		if( (x & 0x3) == 0x3 ) {
+			*q++ = bits;
+			bits = 0;
+		}
+	}
+
+	/* Any left-over bits? Need to be left-aligned.
+	*/
+	if( (x & 0x3) != 0 )
+		*q++ = (wtiff->miniswhite ? ~bits : bits) << (8 - ((x & 0x3) << 1));
+}
+
+/* Pack 8 bit VIPS to 4 bit TIFF.
+ */
+static void
+eightbit2fourbit( Wtiff *wtiff, VipsPel *q, VipsPel *p, int n )
+{
+    int x;
+    VipsPel bits;
+	VipsPel mask = wtiff->miniswhite ? 15 : 0;
+    bits = 0;
+	
+	for( x = 0; x < n; x++ ) {
+		bits <<= 4;
+		bits |= (p[x] >> 4) ^ mask;
+
+		if( (x & 0x1) == 0x1 ) {
+				*q++ = bits;
+				bits = 0;
+		}
+	}
+
+    /* Any left-over bits? Need to be left-aligned.
+     */
+    if( (x & 0x1) != 0 )
+        *q++ = ((VipsPel)(wtiff->miniswhite ? ~bits : bits)) 
+				<< (8 - ((x & 0x1) << 2));
+}
+
 /* Swap the sense of the first channel, if necessary. 
  */
 #define GREY_LOOP( TYPE, MAX ) { \
@@ -1444,8 +1511,12 @@ wtiff_pack2tiff( Wtiff *wtiff, Layer *layer,
 
 		if( wtiff->ready->Coding == VIPS_CODING_LABQ )
 			LabQ2LabC( q, p, area->width );
-		else if( wtiff->squash ) 
+		else if( wtiff->bitdepth == 1 )
 			eightbit2onebit( wtiff, q, p, area->width );
+		else if( wtiff->bitdepth == 2 )
+			eightbit2twobit( wtiff, q, p, area->width );
+		else if( wtiff->bitdepth == 4 )
+			eightbit2fourbit( wtiff, q, p, area->width );
 		else if( wtiff->input->Type == VIPS_INTERPRETATION_XYZ )
 			XYZ2tiffxyz( q, p, area->width, in->im->Bands );
 		else if( (in->im->Bands == 1 || in->im->Bands == 2) && 
@@ -1543,10 +1614,18 @@ wtiff_layer_write_strip( Wtiff *wtiff, Layer *layer, VipsRegion *strip )
 			XYZ2tiffxyz( wtiff->tbuf, p, im->Xsize, im->Bands );
 			p = wtiff->tbuf;
 		}
-		else if( wtiff->squash ) {
+		else if( wtiff->bitdepth == 1 ) {
 			eightbit2onebit( wtiff, wtiff->tbuf, p, im->Xsize );
 			p = wtiff->tbuf;
 		}
+		else if( wtiff->bitdepth == 2 ) {
+			eightbit2twobit( wtiff, wtiff->tbuf, p, im->Xsize );
+			p = wtiff->tbuf;
+		}
+		else if( wtiff->bitdepth == 4 ) {
+			eightbit2fourbit( wtiff, wtiff->tbuf, p, im->Xsize );
+			p = wtiff->tbuf;
+		}
 		else if( (im->Bands == 1 || im->Bands == 2) && 
 			wtiff->miniswhite ) {
 			invert_band0( wtiff, wtiff->tbuf, p, im->Xsize );
@@ -2042,7 +2121,7 @@ vips__tiff_write( VipsImage *input, const char *filename,
 	char *profile,
 	gboolean tile, int tile_width, int tile_height,
 	gboolean pyramid,
-	gboolean squash,
+	int bitdepth,
 	gboolean miniswhite,
 	VipsForeignTiffResunit resunit, double xres, double yres,
 	gboolean bigtiff,
@@ -2064,7 +2143,7 @@ vips__tiff_write( VipsImage *input, const char *filename,
 
 	if( !(wtiff = wtiff_new( input, filename, 
 		compression, Q, predictor, profile,
-		tile, tile_width, tile_height, pyramid, squash,
+                tile, tile_width, tile_height, pyramid, bitdepth,
 		miniswhite, resunit, xres, yres, bigtiff, rgbjpeg, 
 		properties, strip, region_shrink, level, lossless, depth,
 		subifd )) )
@@ -2088,7 +2167,7 @@ vips__tiff_write_buf( VipsImage *input,
 	char *profile,
 	gboolean tile, int tile_width, int tile_height,
 	gboolean pyramid,
-	gboolean squash,
+	int bitdepth,
 	gboolean miniswhite,
 	VipsForeignTiffResunit resunit, double xres, double yres,
 	gboolean bigtiff,
@@ -2106,7 +2185,7 @@ vips__tiff_write_buf( VipsImage *input,
 
 	if( !(wtiff = wtiff_new( input, NULL, 
 		compression, Q, predictor, profile,
-		tile, tile_width, tile_height, pyramid, squash,
+                tile, tile_width, tile_height, pyramid, bitdepth,
 		miniswhite, resunit, xres, yres, bigtiff, rgbjpeg, 
 		properties, strip, region_shrink, level, lossless, depth,
 		subifd )) )