add --strip option to jpegsave

drops all metadata

ChangeLog

@@ -20,6 +20,7 @@
 - vips_gamma() works for any format
 - add --linear mode to vipsthumbnail
 - support XYZ as a PCS for vips_icc_import() and vips_icc_export()
+- add --strip option to jpegsave
 
 18/10/13	started 7.36.3
 - fix compiler warnings in ubuntu 13.10

libvips/foreign/foreign.c

@@ -1994,6 +1994,7 @@ vips_jpegload( const char *filename, VipsImage **out, ... )
  * @profile: attach this ICC profile
  * @optimize_coding: compute optimal Huffman coding tables
  * @interlace: write an interlaced (progressive) jpeg
+ * @strip: remove all metadata from image
  *
  * Write a VIPS image to a file as JPEG.
  *
@@ -2025,6 +2026,9 @@ vips_jpegload( const char *filename, VipsImage **out, ... )
  * in jpg parlance). These files may be better for display over a slow network
  * conection, but need much more memory to encode and decode. 
  *
+ * If @strip is set, no EXIF data, IPCT data, ICC profile or XMP metadata is 
+ * written into the output file. 
+ *
  * See also: vips_jpegsave_buffer(), vips_image_write_file().
  *
  * Returns: 0 on success, -1 on error.
@@ -2055,6 +2059,7 @@ vips_jpegsave( VipsImage *in, const char *filename, ... )
  * @profile: attach this ICC profile
  * @optimize_coding: compute optimal Huffman coding tables
  * @interlace: write an interlaced (progressive) jpeg
+ * @strip: remove all metadata from image
  *
  * As vips_jpegsave(), but save to a memory buffer. 
  *
@@ -2104,6 +2109,7 @@ vips_jpegsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
  * @Q: JPEG quality factor
  * @profile: attach this ICC profile
  * @optimize_coding: compute optimal Huffman coding tables
+ * @strip: remove all metadata from image
  *
  * As vips_jpegsave(), but save as a mime jpeg on stdout.
  *

libvips/foreign/jpegsave.c

@@ -87,6 +87,10 @@ typedef struct _VipsForeignSaveJpeg {
 	 */
 	gboolean interlace;
 
+	/* Remove all metadata from the image. 
+	 */
+	gboolean strip;
+
 } VipsForeignSaveJpeg;
 
 typedef VipsForeignSaveClass VipsForeignSaveJpegClass;
@@ -146,6 +150,13 @@ vips_foreign_save_jpeg_class_init( VipsForeignSaveJpegClass *class )
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsForeignSaveJpeg, interlace ),
 		FALSE );
+
+	VIPS_ARG_BOOL( class, "strip", 14,
+		_( "Strip" ),
+		_( "Strip all metadata from image" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveJpeg, strip ),
+		FALSE );
 }
 
 static void
@@ -181,7 +192,7 @@ vips_foreign_save_jpeg_file_build( VipsObject *object )
 
 	if( vips__jpeg_write_file( save->ready, file->filename,
 		jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
-		jpeg->interlace ) )
+		jpeg->interlace, jpeg->strip ) )
 		return( -1 );
 
 	return( 0 );
@@ -247,7 +258,7 @@ vips_foreign_save_jpeg_buffer_build( VipsObject *object )
 
 	if( vips__jpeg_write_buffer( save->ready, 
 		&obuf, &olen, jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
-		jpeg->interlace ) )
+		jpeg->interlace, jpeg->strip ) )
 		return( -1 );
 
 	area = vips_area_new_blob( (VipsCallbackFn) vips_free, obuf, olen );
@@ -309,7 +320,7 @@ vips_foreign_save_jpeg_mime_build( VipsObject *object )
 
 	if( vips__jpeg_write_buffer( save->ready, 
 		&obuf, &olen, jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
-		jpeg->interlace ) )
+		jpeg->interlace, jpeg->strip ) )
 		return( -1 );
 
 	printf( "Content-length: %zd\r\n", olen );

libvips/foreign/vips2jpeg.c

@@ -58,6 +58,8 @@
  * 	- attach IPCT data (app13), thanks Gary
  * 2/10/13 Lovell Fuller
  * 	- add optimize_coding parameter
+ * 12/11/13
+ * 	- add "strip" option to remove all metadata
  */
 
 /*
@@ -841,7 +843,7 @@ write_jpeg_block( REGION *region, Rect *area, void *a )
  */
 static int
 write_vips( Write *write, int qfac, const char *profile, 
-	gboolean optimize_coding, gboolean progressive )
+	gboolean optimize_coding, gboolean progressive, gboolean strip )
 {
 	VipsImage *in;
 	J_COLOR_SPACE space;
@@ -909,22 +911,26 @@ write_vips( Write *write, int qfac, const char *profile,
 
 	/* Write any APP markers we need.
 	 */
-	if( write_exif( write ) ||
+	if( !strip ) { 
-		write_blob( write, VIPS_META_XMP_NAME, JPEG_APP0 + 1 ) ||
+		if( write_exif( write ) ||
-		write_blob( write, VIPS_META_IPCT_NAME, JPEG_APP0 + 13 ) )
+			write_blob( write, 
-		return( -1 );
+				VIPS_META_XMP_NAME, JPEG_APP0 + 1 ) ||
+			write_blob( write, 
+				VIPS_META_IPCT_NAME, JPEG_APP0 + 13 ) )
+			return( -1 );
 
-	/* A profile supplied as an argument overrides an embedded profile.
+		/* A profile supplied as an argument overrides an embedded 
-	 * "none" means don't attach a profile.
+		 * profile. "none" means don't attach a profile.
-	 */
+		 */
-	if( profile && 
+		if( profile && 
-		strcmp( profile, "none" ) != 0 &&
+			strcmp( profile, "none" ) != 0 &&
-		write_profile_file( write, profile ) )
+			write_profile_file( write, profile ) )
-		return( -1 );
+			return( -1 );
-	if( !profile && 
+		if( !profile && 
-		vips_image_get_typeof( in, VIPS_META_ICC_NAME ) && 
+			vips_image_get_typeof( in, VIPS_META_ICC_NAME ) && 
-		write_profile_meta( write ) )
+			write_profile_meta( write ) )
-		return( -1 );
+			return( -1 );
+	}
 
 	/* Write data. Note that the write function grabs the longjmp()!
 	 */
@@ -946,7 +952,7 @@ write_vips( Write *write, int qfac, const char *profile,
 int
 vips__jpeg_write_file( VipsImage *in, 
 	const char *filename, int Q, const char *profile, 
-	gboolean optimize_coding, gboolean progressive )
+	gboolean optimize_coding, gboolean progressive, gboolean strip )
 {
 	Write *write;
 
@@ -976,7 +982,8 @@ vips__jpeg_write_file( VipsImage *in,
 
 	/* Convert!
 	 */
-	if( write_vips( write, Q, profile, optimize_coding, progressive ) ) {
+	if( write_vips( write, 
+		Q, profile, optimize_coding, progressive, strip ) ) {
 		write_destroy( write );
 		return( -1 );
 	}
@@ -1223,7 +1230,8 @@ buf_dest( j_compress_ptr cinfo, void **obuf, size_t *olen )
 int
 vips__jpeg_write_buffer( VipsImage *in, 
 	void **obuf, size_t *olen, int Q, const char *profile, 
-	gboolean optimize_coding, gboolean progressive )
+	gboolean optimize_coding, gboolean progressive,
+	gboolean strip )
 {
 	Write *write;
 
@@ -1252,7 +1260,8 @@ vips__jpeg_write_buffer( VipsImage *in,
 
 	/* Convert!
 	 */
-	if( write_vips( write, Q, profile, optimize_coding, progressive ) ) {
+	if( write_vips( write, 
+		Q, profile, optimize_coding, progressive, strip ) ) {
 		write_destroy( write );
 
 		return( -1 );

libvips/foreign/vipsjpeg.h

@@ -39,10 +39,10 @@ extern const char *vips__jpeg_suffs[];
 
 int vips__jpeg_write_file( VipsImage *in, 
 	const char *filename, int Q, const char *profile, 
-	gboolean optimize_coding, gboolean progressive );
+	gboolean optimize_coding, gboolean progressive, gboolean strip );
 int vips__jpeg_write_buffer( VipsImage *in, 
 	void **obuf, size_t *olen, int Q, const char *profile, 
-	gboolean optimize_coding, gboolean progressive );
+	gboolean optimize_coding, gboolean progressive, gboolean strip );
 
 int vips__isjpeg( const char *filename );
 int vips__jpeg_read_file( const char *name, VipsImage *out,