Add cjpeg -rgb option from jpeg-8d

ChangeLog.txt

@@ -30,6 +30,9 @@ without having to pass -Djava.library.path=/usr/lib to java.
 the performance of the TurboJPEG Java API.  It can be run with
 'java -cp turbojpeg.jar TJBench'.
 
+[8] cjpeg can now be used to generate JPEG files with the RGB colorspace
+(feature ported from jpeg-8d.)
+
 
 1.2.1
 =====

change.log

@@ -4,6 +4,15 @@ information relevant to libjpeg-turbo.
 CHANGE LOG for Independent JPEG Group's JPEG software
 
 
+Version 8d  15-Jan-2012
+-----------------------
+
+Add cjpeg -rgb option to create RGB JPEG files.
+Using this switch suppresses the conversion from RGB
+colorspace input to the default YCbCr JPEG colorspace.
+Thank to Michael Koch for the initial suggestion.
+
+
 Version 8b  16-May-2010
 -----------------------
 

cjpeg.1

@@ -49,6 +49,11 @@ By saying
 .BR \-grayscale ,
 you'll get a smaller JPEG file that takes less time to process.
 .TP
+.B \-rgb
+Create RGB JPEG file.
+Using this switch suppresses the conversion from RGB
+colorspace input to the default YCbCr JPEG colorspace.
+.TP
 .B \-optimize
 Perform optimization of entropy encoding parameters.  Without this, default
 encoding parameters are used.

cjpeg.c

@@ -3,7 +3,7 @@
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1998, Thomas G. Lane.
- * Modified 2003-2008 by Guido Vollbeding.
+ * Modified 2003-2011 by Guido Vollbeding.
  * Modifications:
  * Copyright (C) 2010, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
@@ -155,6 +155,7 @@ usage (void)
   fprintf(stderr, "Switches (names may be abbreviated):\n");
   fprintf(stderr, "  -quality N[,...]   Compression quality (0..100; 5-95 is useful range)\n");
   fprintf(stderr, "  -grayscale     Create monochrome JPEG file\n");
+  fprintf(stderr, "  -rgb           Create RGB JPEG file\n");
 #ifdef ENTROPY_OPT_SUPPORTED
   fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
 #endif
@@ -289,6 +290,10 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
       /* Force a monochrome JPEG file to be generated. */
       jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
 
+    } else if (keymatch(arg, "rgb", 3)) {
+      /* Force an RGB JPEG file to be generated. */
+      jpeg_set_colorspace(cinfo, JCS_RGB);
+
     } else if (keymatch(arg, "maxmemory", 3)) {
       /* Maximum memory in Kb (or Mb with 'm'). */
       long lval;

usage.txt

@@ -80,6 +80,10 @@ The basic command line switches for cjpeg are:
 			saying -grayscale, you'll get a smaller JPEG file that
 			takes less time to process.
 
+	-rgb		Create RGB JPEG file.
+			Using this switch suppresses the conversion from RGB
+			colorspace input to the default YCbCr JPEG colorspace.
+
 	-optimize	Perform optimization of entropy encoding parameters.
 			Without this, default encoding parameters are used.
 			-optimize usually makes the JPEG file a little smaller,