[wip] low overhead icc for jpeg

third_party/iccjpeg/iccjpeg.h

 /*
  * iccprofile.h
  *
  * This file provides code to read and write International Color Consortium
  * (ICC) device profiles embedded in JFIF JPEG image files.  The ICC has
  * defined a standard format for including such data in JPEG "APP2" markers.
  * The code given here does not know anything about the internal structure
  * of the ICC profile data; it just knows how to put the profile data into
  * a JPEG file being written, or get it back out when reading.
  *
@@ skipping 58 matching lines @@
  * and must be freed by the caller with free() when the caller no longer
  * needs it.  (Alternatively, we could write this routine to use the
  * IJG library's memory allocator, so that the data would be freed implicitly
  * at jpeg_finish_decompress() time.  But it seems likely that many apps
  * will prefer to have the data stick around after decompression finishes.)
  */
 
 extern boolean read_icc_profile JPP((j_decompress_ptr cinfo,
                                      JOCTET **icc_data_ptr,
                                      unsigned int *icc_data_len));
+
+
+/*
+ * Write the given ICCbis profile data into a JPEG file.
+ * It *must* be called AFTER calling jpeg_start_compress() and BEFORE
+ * the first call to jpeg_write_scanlines().
+ * (This ordering ensures that the APP2 marker(s) will appear after the
+ * SOI and JFIF or Adobe markers, but before all else.)
+ */
+
+extern void write_icc_profile_bis JPP((j_compress_ptr cinfo,
+                   JOCTET profile,
+                   JOCTET intent));
+
+
+/*
+ * See if there was an ICCbis profile in the JPEG file being read; the
+ * ICCbis profile is returned (0 for invalid / not found). If found,
+ * write the rendering-intent to *intent (if given).
+ */
+
+extern unsigned int read_icc_profile_bis JPP((j_decompress_ptr cinfo,
+                          unsigned int *intent));
+
+
+/*
+ * Known ICCbis profiles are non-zero:
+ */
+
+#define ICCBISsRGB         0x01
+#define ICCBISadobeRGB1998 0x02