From: DRC <dcommander@users.sourceforge.net>
Date: Sun, 10 Oct 2010 07:21:55 +0000 (+0000)
Subject: Add option for setting luminance & chrominance quality independently (currently only... 
X-Git-Tag: 1.0.90~68
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=294079cbe090416bc221e2a446d951c590cc4b38;p=libjpeg-turbo

Add option for setting luminance & chrominance quality independently (currently only works if using libjpeg v7 or v8 code base)


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@248 632fc199-4ca6-4c93-a231-07263d6284db
---

294079cbe090416bc221e2a446d951c590cc4b38
diff --cc cjpeg.1
index d175a96,01bfa25..3aee807
--- a/cjpeg.1
+++ b/cjpeg.1
@@@ -276,11 -314,8 +301,10 @@@ Communications of the ACM, April 1991 (
  .SH AUTHOR
  Independent JPEG Group
  .SH BUGS
 +Arithmetic coding is not supported for legal reasons.
 +.PP
  GIF input files are no longer supported, to avoid the Unisys LZW patent.
- Use a Unisys-licensed program if you need to read a GIF file.  (Conversion
- of GIF files to JPEG is usually a bad idea anyway.)
+ (Conversion of GIF files to JPEG is usually a bad idea anyway.)
  .PP
  Not all variants of BMP and Targa file formats are supported.
  .PP
diff --cc cjpeg.c
index 648abf2,b9d57eb..3daa259
--- a/cjpeg.c
+++ b/cjpeg.c
@@@ -2,7 -2,7 +2,8 @@@
   * cjpeg.c
   *
   * Copyright (C) 1991-1998, Thomas G. Lane.
+  * Modified 2003-2008 by Guido Vollbeding.
 + * Copyright (C) 2010, D. R. Commander.
   * This file is part of the Independent JPEG Group's software.
   * For conditions of distribution and use, see the accompanying README file.
   *
@@@ -387,7 -383,15 +380,7 @@@ parse_switches (j_compress_ptr cinfo, i
         * default sampling factors.
         */
  
-     } else if (keymatch(arg, "scans", 2)) {
 -    } else if (keymatch(arg, "scale", 4)) {
 -      /* Scale the image by a fraction M/N. */
 -      if (++argn >= argc)	/* advance to next argument */
 -	usage();
 -      if (sscanf(argv[argn], "%d/%d",
 -		 &cinfo->scale_num, &cinfo->scale_denom) != 2)
 -	usage();
 -
+     } else if (keymatch(arg, "scans", 4)) {
        /* Set scan script. */
  #ifdef C_MULTISCAN_FILES_SUPPORTED
        if (++argn >= argc)	/* advance to next argument */
diff --cc rdswitch.c
index 4f4bb4f,7a839af..d34b400
--- a/rdswitch.c
+++ b/rdswitch.c
@@@ -69,9 -70,8 +70,12 @@@ read_text_integer (FILE * file, long * 
  }
  
  
++#if JPEG_LIB_VERSION < 70
++static int q_scale_factor = 100;
++#endif
++
  GLOBAL(boolean)
- read_quant_tables (j_compress_ptr cinfo, char * filename,
- 		   int scale_factor, boolean force_baseline)
+ read_quant_tables (j_compress_ptr cinfo, char * filename, boolean force_baseline)
  /* Read a set of quantization tables from the specified file.
   * The file is plain ASCII text: decimal numbers with whitespace between.
   * Comments preceded by '#' may be included in the file.
@@@ -108,7 -108,8 +112,12 @@@
        }
        table[i] = (unsigned int) val;
      }
-     jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
++#if JPEG_LIB_VERSION >= 70
+     jpeg_add_quant_table(cinfo, tblno, table, cinfo->q_scale_factor[tblno],
+ 			 force_baseline);
++#else
++    jpeg_add_quant_table(cinfo, tblno, table, q_scale_factor, force_baseline);
++#endif
      tblno++;
    }
  
@@@ -262,6 -263,38 +271,46 @@@ bogus
  #endif /* C_MULTISCAN_FILES_SUPPORTED */
  
  
+ GLOBAL(boolean)
+ set_quality_ratings (j_compress_ptr cinfo, char *arg, boolean force_baseline)
+ /* Process a quality-ratings parameter string, of the form
+  *     N[,N,...]
+  * If there are more q-table slots than parameters, the last value is replicated.
+  */
+ {
+   int val = 75;			/* default value */
+   int tblno;
+   char ch;
+ 
+   for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
+     if (*arg) {
+       ch = ',';			/* if not set by sscanf, will be ',' */
+       if (sscanf(arg, "%d%c", &val, &ch) < 1)
+ 	return FALSE;
+       if (ch != ',')		/* syntax check */
+ 	return FALSE;
+       /* Convert user 0-100 rating to percentage scaling */
++#if JPEG_LIB_VERSION >= 70
+       cinfo->q_scale_factor[tblno] = jpeg_quality_scaling(val);
++#endif
+       while (*arg && *arg++ != ',') /* advance to next segment of arg string */
+ 	;
+     } else {
+       /* reached end of parameter, set remaining factors to last value */
++#if JPEG_LIB_VERSION >= 70
+       cinfo->q_scale_factor[tblno] = jpeg_quality_scaling(val);
++#endif
+     }
+   }
++#if JPEG_LIB_VERSION >= 70
+   jpeg_default_qtables(cinfo, force_baseline);
++#else
++  jpeg_set_quality(cinfo, val, force_baseline);
++#endif
+   return TRUE;
+ }
+ 
+ 
  GLOBAL(boolean)
  set_quant_slots (j_compress_ptr cinfo, char *arg)
  /* Process a quantization-table-selectors parameter string, of the form