jpegtran: Add option to copy only ICC markers

Closes #533

ChangeLog.md

@@ -15,6 +15,10 @@ undefined C compiler behavior led to crashes ("SIGBUS: illegal alignment") on
 Android systems when running AArch32/Thumb builds of libjpeg-turbo built with
 recent versions of Clang.
 
+4. Added a command-line argument (`-copy icc`) to jpegtran that causes it to
+copy only the ICC profile markers from the source file and discard any other
+metadata.
+
 
 2.1.0
 =====

jpegtran.1

@@ -1,4 +1,4 @@
-.TH JPEGTRAN 1 "26 October 2020"
+.TH JPEGTRAN 1 "13 July 2021"
 .SH NAME
 jpegtran \- lossless transformation of JPEG files
 .SH SYNOPSIS
@@ -247,6 +247,10 @@ comments and other metadata in the source file.
 Copy only comment markers.  This setting copies comments from the source file
 but discards any other metadata.
 .TP
+.B \-copy icc
+Copy only ICC profile markers.  This setting copies the ICC profile from the
+source file but discards any other metadata.
+.TP
 .B \-copy all
 Copy all extra markers.  This setting preserves miscellaneous markers
 found in the source file, such as JFIF thumbnails, Exif data, and Photoshop
@@ -261,7 +265,7 @@ Additional switches recognized by jpegtran are:
 .BI \-icc " file"
 Embed ICC color management profile contained in the specified file.  Note that
 this will cause \fBjpegtran\fR to ignore any APP2 markers in the input file,
-even if \fB-copy all\fR is specified.
+even if \fB-copy all\fR or \fB-copy icc\fR is specified.
 .TP
 .BI \-maxmemory " N"
 Set limit for amount of memory to use in processing large images.  Value is

jpegtran.c

@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1995-2019, Thomas G. Lane, Guido Vollbeding.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2010, 2014, 2017, 2019-2020, D. R. Commander.
+ * Copyright (C) 2010, 2014, 2017, 2019-2021, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -64,6 +64,7 @@ usage(void)
   fprintf(stderr, "Switches (names may be abbreviated):\n");
   fprintf(stderr, "  -copy none     Copy no extra markers from source file\n");
   fprintf(stderr, "  -copy comments Copy only comment markers (default)\n");
+  fprintf(stderr, "  -copy icc      Copy only ICC profile markers\n");
   fprintf(stderr, "  -copy all      Copy all extra markers\n");
 #ifdef ENTROPY_OPT_SUPPORTED
   fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
@@ -196,6 +197,8 @@ parse_switches(j_compress_ptr cinfo, int argc, char **argv,
         copyoption = JCOPYOPT_NONE;
       } else if (keymatch(argv[argn], "comments", 1)) {
         copyoption = JCOPYOPT_COMMENTS;
+      } else if (keymatch(argv[argn], "icc", 1)) {
+        copyoption = JCOPYOPT_ICC;
       } else if (keymatch(argv[argn], "all", 1)) {
         copyoption = JCOPYOPT_ALL;
       } else
@@ -570,6 +573,8 @@ main(int argc, char **argv)
     fclose(icc_file);
     if (copyoption == JCOPYOPT_ALL)
       copyoption = JCOPYOPT_ALL_EXCEPT_ICC;
+    if (copyoption == JCOPYOPT_ICC)
+      copyoption = JCOPYOPT_NONE;
   }
 
   if (report) {

transupp.c

@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1997-2019, Thomas G. Lane, Guido Vollbeding.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2010, 2017, D. R. Commander.
+ * Copyright (C) 2010, 2017, 2021, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -2310,7 +2310,7 @@ jcopy_markers_setup(j_decompress_ptr srcinfo, JCOPY_OPTION option)
   int m;
 
   /* Save comments except under NONE option */
-  if (option != JCOPYOPT_NONE) {
+  if (option != JCOPYOPT_NONE && option != JCOPYOPT_ICC) {
     jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
   }
   /* Save all types of APPn markers iff ALL option */
@@ -2321,6 +2321,10 @@ jcopy_markers_setup(j_decompress_ptr srcinfo, JCOPY_OPTION option)
       jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
     }
   }
+  /* Save only APP2 markers if ICC option selected */
+  if (option == JCOPYOPT_ICC) {
+    jpeg_save_markers(srcinfo, JPEG_APP0 + 2, 0xFFFF);
+  }
 #endif /* SAVE_MARKERS_SUPPORTED */
 }
 

transupp.h

@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1997-2019, Thomas G. Lane, Guido Vollbeding.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2017, D. R. Commander.
+ * Copyright (C) 2017, 2021, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -216,7 +216,8 @@ typedef enum {
   JCOPYOPT_NONE,           /* copy no optional markers */
   JCOPYOPT_COMMENTS,       /* copy only comment (COM) markers */
   JCOPYOPT_ALL,            /* copy all optional markers */
-  JCOPYOPT_ALL_EXCEPT_ICC /* copy all optional markers except APP2 */
+  JCOPYOPT_ALL_EXCEPT_ICC, /* copy all optional markers except APP2 */
+  JCOPYOPT_ICC             /* copy only ICC profile (APP2) markers */
 } JCOPY_OPTION;
 
 #define JCOPYOPT_DEFAULT  JCOPYOPT_COMMENTS     /* recommended default */

usage.txt

@@ -601,6 +601,9 @@ markers, such as comment blocks:
         -copy comments  Copy only comment markers.  This setting copies
                         comments from the source file but discards any other
                         metadata.
+        -copy icc       Copy only ICC profile markers.  This setting copies the
+                        ICC profile from the source file but discards any other
+                        metadata.
         -copy all       Copy all extra markers.  This setting preserves
                         miscellaneous markers found in the source file, such
                         as JFIF thumbnails, Exif data, and Photoshop settings.