IJG's JPEG software v6b with lossless JPEG support

Patch obtained from:
https://sourceforge.net/projects/jpeg/files/ftp.oceana.com

Author date taken from original announcement and timestamp of patch
tarball:
https://groups.google.com/g/comp.protocols.dicom/c/rrkP8BxoMRk/m/Ij4dfprggp8J

cjpeg.c

@@ -157,6 +157,9 @@ usage (void)
 #ifdef C_PROGRESSIVE_SUPPORTED
   fprintf(stderr, "  -progressive   Create progressive JPEG file\n");
 #endif
+#ifdef C_LOSSLESS_SUPPORTED
+  fprintf(stderr, "  -lossless psv[,Pt]  Create lossless JPEG file\n");
+#endif
 #ifdef TARGA_SUPPORTED
   fprintf(stderr, "  -targa         Input file is Targa format (usually not needed)\n");
 #endif
@@ -217,6 +220,7 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
   char * qslotsarg = NULL;	/* saves -qslots parm if any */
   char * samplearg = NULL;	/* saves -sample parm if any */
   char * scansarg = NULL;	/* saves -scans parm if any */
+  char * losslsarg = NULL;	/* saves -lossless parm if any */
 
   /* Set up default JPEG parameters. */
   /* Note that default -quality level need not, and does not,
@@ -287,6 +291,19 @@ 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, "lossless", 1)) {
+/* Select simple lossless mode. */
+#ifdef C_LOSSLESS_SUPPORTED
+      if (++argn >= argc)	/* advance to next argument */
+	usage();
+      losslsarg = argv[argn];
+      /* We must postpone execution until num_components is known. */
+#else
+      fprintf(stderr, "%s: sorry, lossless output was not compiled\n",
+	      progname);
+      exit(EXIT_FAILURE);
+#endif
+
     } else if (keymatch(arg, "maxmemory", 3)) {
       /* Maximum memory in Kb (or Mb with 'm'). */
       long lval;
@@ -442,6 +459,12 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
       jpeg_simple_progression(cinfo);
 #endif
 
+#ifdef C_LOSSLESS_SUPPORTED
+    if (losslsarg != NULL)	/* process -lossless if it was present */
+      if (! set_simple_lossless(cinfo, losslsarg))
+	usage();
+#endif
+
 #ifdef C_MULTISCAN_FILES_SUPPORTED
     if (scansarg != NULL)	/* process -scans if it was present */
       if (! read_scan_script(cinfo, scansarg))