Add cjpeg -rgb option from jpeg-8d

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@880 632fc199-4ca6-4c93-a231-07263d6284db

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;