Refine colorInteropID support

src/bin/exr2aces/main.cpp

@@ -34,6 +34,9 @@ usageMessage (ostream& stream, const char* program_name, bool verbose = false)
 {
     stream << "Usage: " << program_name << " [options] infile outfile" << endl;
 
+    // TODO: The text below needs to be updated to reflect the actual
+    // SMPTE ST 2065-4 standard.
+
     if (verbose)
         stream
             << "\n"

src/bin/exrstdattr/main.cpp

@@ -84,7 +84,12 @@ usageMessage (ostream& stream, const char* program_name, bool verbose = false)
                "  -chromaticities f f f f f f f f\n"
                "        CIE xy chromaticities for the red, green\n"
                "        and blue primaries, and for the white point\n"
-               "        (8 floats)\n"
+               "        (8 floats). This attribute is superseded by\n"
+               "        colorInteropID for most purposes.\n"
+               "\n"
+               "  -colorInteropID s\n"
+               "        Color Interop Forum ID that identifies the\n"
+               "        color space of the RGB image data (string)\n"
                "\n"
                "  -whiteLuminance f\n"
                "        white luminance, in candelas per square meter\n"
@@ -644,6 +649,10 @@ main (int argc, char** argv)
             {
                 getChromaticities (attrName, argc, argv, i, part, attrs);
             }
+            else if (!strcmp (argv[i], "-colorInteropID"))
+            {
+                getString (attrName, argc, argv, i, part, attrs);
+            }
             else if (!strcmp (argv[i], "-whiteLuminance"))
             {
                 getFloat (attrName, argc, argv, i, part, attrs);

src/lib/OpenEXR/ImfAcesFile.cpp

@@ -34,6 +34,13 @@ acesChromaticities ()
     return acesChr;
 }
 
+const std::string&
+acesColorInteropID ()
+{
+    static const std::string acesID = "lin_ap0_scene";
+    return acesID;
+}
+
 class AcesOutputFile::Data
 {
 public:
@@ -92,6 +99,7 @@ AcesOutputFile::AcesOutputFile (
     Header newHeader = header;
     addChromaticities (newHeader, acesChromaticities ());
     addAdoptedNeutral (newHeader, acesChromaticities ().white);
+    addColorInteropID (newHeader, acesColorInteropID ());
 
     _data->rgbaFile =
         new RgbaOutputFile (name.c_str (), newHeader, rgbaChannels, numThreads);
@@ -111,6 +119,7 @@ AcesOutputFile::AcesOutputFile (
     Header newHeader = header;
     addChromaticities (newHeader, acesChromaticities ());
     addAdoptedNeutral (newHeader, acesChromaticities ().white);
+    addColorInteropID (newHeader, acesColorInteropID ());
 
     _data->rgbaFile = new RgbaOutputFile (os, header, rgbaChannels, numThreads);
 
@@ -143,6 +152,7 @@ AcesOutputFile::AcesOutputFile (
 
     addChromaticities (newHeader, acesChromaticities ());
     addAdoptedNeutral (newHeader, acesChromaticities ().white);
+    addColorInteropID (newHeader, acesColorInteropID ());
 
     _data->rgbaFile =
         new RgbaOutputFile (name.c_str (), newHeader, rgbaChannels, numThreads);
@@ -176,6 +186,7 @@ AcesOutputFile::AcesOutputFile (
 
     addChromaticities (newHeader, acesChromaticities ());
     addAdoptedNeutral (newHeader, acesChromaticities ().white);
+    addColorInteropID (newHeader, acesColorInteropID ());
 
     _data->rgbaFile =
         new RgbaOutputFile (name.c_str (), newHeader, rgbaChannels, numThreads);
@@ -312,6 +323,8 @@ AcesInputFile::Data::~Data ()
 void
 AcesInputFile::Data::initColorConversion ()
 {
+    // TODO: Add support for colorInteropID.
+
     const Header& header = rgbaFile->header ();
 
     Chromaticities fileChr;

src/lib/OpenEXR/ImfAcesFile.h

@@ -6,6 +6,9 @@
 #ifndef INCLUDED_IMF_ACES_FILE_H
 #define INCLUDED_IMF_ACES_FILE_H
 
+// TODO: The text below needs to be updated to reflect the actual
+// SMPTE ST 2065-4 standard.
+
 //-----------------------------------------------------------------------------
 //
 //	ACES image file I/O.
@@ -67,6 +70,13 @@ OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER
 
 const Chromaticities& acesChromaticities ();
 
+//
+// The colorInteropID value for ACES2065-1, per the
+// Color Interop Forum recommendation for OpenEXR files.
+//
+
+const std::string& acesColorInteropID ();
+
 //
 // ACES output file.
 //

src/lib/OpenEXR/ImfMultiPartOutputFile.cpp

@@ -14,6 +14,7 @@
 #include "ImfOutputPartData.h"
 #include "ImfOutputStreamMutex.h"
 #include "ImfPartType.h"
+#include "ImfStandardAttributes.h"
 #include "ImfStdIO.h"
 #include "ImfThreading.h"
 #include "ImfTiledOutputFile.h"
@@ -377,6 +378,18 @@ MultiPartOutputFile::Data::overrideSharedAttributesValues (
         dst.insert ("chromaticities", *chromaticities);
     else
         dst.erase ("chromaticities");
+
+    //
+    // ColorInteropID -- leave a part's existing "data" tag alone, since
+    // it marks image data that is intentionally not color managed.
+    //
+    if (!hasColorInteropID (dst) || colorInteropID (dst) != "data")
+    {
+        if (hasColorInteropID (src))
+            addColorInteropID (dst, colorInteropID (src));
+        else
+            dst.erase ("colorInteropID");
+    }
 }
 
 bool
@@ -447,6 +460,23 @@ MultiPartOutputFile::Data::checkSharedAttributesValues (
         }
     }
 
+    //
+    // ColorInteropID -- a part after the first may omit it (inheriting
+    // the first part's value), or set it to "data" to mark image data
+    // that should not be color managed. Any other value that differs
+    // from the first part's is a conflict.
+    //
+    if (hasColorInteropID (dst) && colorInteropID (dst) != "data")
+    {
+        if ((hasColorInteropID (src) &&
+             colorInteropID (src) != colorInteropID (dst)) ||
+            (!hasColorInteropID (src)))
+        {
+            conflict = true;
+            conflictingAttributes.push_back ("colorInteropID");
+        }
+    }
+
     return conflict;
 }
 

src/lib/OpenEXR/ImfMultiPartOutputFile.h

@@ -21,8 +21,12 @@ OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER
 // * Pixel Aspect Ratio
 // * Time Code
 // * Chromaticities
+// * ColorInteropID
 // The first header forms the basis for the set of attributes that are shared
-// across the constituent parts.
+// across the constituent parts. A part after the first may omit
+// colorInteropID (inheriting the first part's value), or set it to "data"
+// to mark image data that should not be color managed; any other value
+// that differs from the first part's is a conflict.
 //
 // Parameters
 //  headers - pointer to array of headers; one for each part of the image file

src/lib/OpenEXR/ImfRgbaFile.cpp

@@ -104,6 +104,8 @@ prefixFromLayerName (const string& layerName, const Header& header)
 V3f
 ywFromHeader (const Header& header)
 {
+    // TODO: Add support for colorInteropID.
+
     Chromaticities cr;
 
     if (hasChromaticities (header)) cr = chromaticities (header);

src/lib/OpenEXR/ImfStandardAttributes.h

@@ -600,6 +600,26 @@ IMF_STD_ATTRIBUTE_DEF (reelName, ReelName, std::string)
 
 IMF_STD_ATTRIBUTE_DEF (chromaticities, Chromaticities, Chromaticities)
 
+//
+// ColorInteropID -- the Color Interop Forum ID that describes the color space of the RGB images.
+//
+// This is a specially designed string used to communicate the color space of 
+// the image in an interoperable manner. The contents of the string is described
+// in the specification "An ID for Color Interop":
+// <https://github.com/AcademySoftwareFoundation/ColorInterop/blob/main/Recommendations/03_ColorInteropID/ColorInteropID.md>
+//
+// Guidance to application developers is provided in "Identifying the Color Space of OpenEXR Files":
+// <https://github.com/AcademySoftwareFoundation/ColorInterop/blob/main/Recommendations/04_OpenEXRFiles/OpenEXRFiles.md>
+// 
+// Please adhere to the following usage guidance:
+//   1. If the color space of an image is modified, do not forward the stale attribute value.
+//   2. Do not set this to a default color space. If the actual color space is not known, omit
+//      the attribute or set it to "unknown".
+//
+// New in OpenEXR v3.4
+
+IMF_STD_ATTRIBUTE_DEF (colorInteropID, ColorInteropID, std::string)
+
 //
 // whiteLuminance -- for RGB images, defines the luminance, in Nits
 // (candelas per square meter) of the RGB value (1.0, 1.0, 1.0).
@@ -724,25 +744,4 @@ IMF_STD_ATTRIBUTE_DEF_DEPRECATED (
 
 IMF_STD_ATTRIBUTE_DEF (idManifest, IDManifest, CompressedIDManifest)
 
-//
-// ColorInteropID -- the Color Interop Forum ID that describes the color space of the RGB images.
-//
-// This is a specially designed string used to communicate the color space of 
-// the image in an interoperable manner. The contents of the string is described
-// in the specification "An ID for Color Interop":
-// <https://docs.google.com/document/d/1T94lYbis9uCskL_ZEMxGBF2JryLfZnjxlEoNgRHZzBE/edit?usp=sharing>
-//
-// Guidance to application developers is provided in "Identifying the Color Space of OpenEXR Files":
-// <https://docs.google.com/document/d/1MTH1bq2L67ifvdDf64Amhzg4AbkIM5LG6yPHrB96Vwo/edit?usp=sharing>
-// 
-// Please adhere to the following usage guidance:
-//   1. If the color space of an image is modified, do not forward the stale attribute value.
-//   2. Do not set this to a default color space. If the actual color space is not known, omit
-//      the attribute or set it to "unknown".
-//
-// New in OpenEXR v3.4
-
-
-IMF_STD_ATTRIBUTE_DEF (colorInteropID, ColorInteropID, std::string)
-
 #endif

src/lib/OpenEXRCore/parse_header.c

@@ -2857,7 +2857,7 @@ internal_exr_parse_header (exr_context_t ctxt)
     {
         for ( int p = 1; p < ctxt->num_parts; ++p )
         {
-            const char *mismatch[4] = { NULL, NULL, NULL, NULL };
+            const char *mismatch[5] = { NULL, NULL, NULL, NULL, NULL };
             int mismatchcount = 0;
             exr_priv_part_t curp = ctxt->parts[p];
 
@@ -2872,15 +2872,17 @@ internal_exr_parse_header (exr_context_t ctxt)
                 rv = ctxt->print_error (
                     ctxt,
                     rv,
-                    "Part %d (%s) has non-conforming shared attributes: %s%s%s%s%s%s%s",
+                    "Part %d (%s) has non-conforming shared attributes: %s%s%s%s%s%s%s%s%s",
                     p, curp->name ? curp->name->string->str : "<missing name>",
                     mismatch[0] ? mismatch[0] : "",
                     mismatch[0] ? " " : "",
                     mismatch[1] ? mismatch[1] : "",
                     mismatch[1] ? " " : "",
                     mismatch[2] ? mismatch[2] : "",
                     mismatch[2] ? " " : "",
-                    mismatch[3] ? mismatch[3] : "");
+                    mismatch[3] ? mismatch[3] : "",
+                    mismatch[3] ? " " : "",
+                    mismatch[4] ? mismatch[4] : "");
 
                 // MultiPartInputFile would fail unconditionally
                 break;

src/lib/OpenEXRCore/validation.c

@@ -830,6 +830,47 @@ internal_exr_validate_shared_attrs (exr_context_t ctxt,
     if (rv != EXR_ERR_SUCCESS)
         mismatchattr[misidx++] = "chromaticities";
 
+    /*
+     * colorInteropID only needs to be set on the first part; later parts
+     * may omit it (inheriting the first part's color space) or set it to
+     * "data" to mark images that should not be color managed. Any other
+     * value on a later part that differs from the first part's is a
+     * mismatch.
+     */
+    rv  = exr_get_attribute_by_name (ctxt, 0, "colorInteropID", &battr);
+    rv1 = exr_get_attribute_by_name (ctxt, curpartidx, "colorInteropID", &cattr);
+    if (EXR_ERR_SUCCESS == rv1)
+    {
+        if (cattr->type != EXR_ATTR_STRING)
+        {
+            rv = EXR_ERR_ATTR_TYPE_MISMATCH;
+        }
+        else if (
+            cattr->string->length == 4 &&
+            0 == memcmp (cattr->string->str, "data", 4))
+        {
+            rv = EXR_ERR_SUCCESS;
+        }
+        else if (
+            EXR_ERR_SUCCESS == rv && battr->type == EXR_ATTR_STRING &&
+            battr->string->length == cattr->string->length &&
+            0 == memcmp (
+                     battr->string->str,
+                     cattr->string->str,
+                     (size_t) cattr->string->length))
+        {
+            rv = EXR_ERR_SUCCESS;
+        }
+        else
+        {
+            rv = EXR_ERR_ATTR_TYPE_MISMATCH;
+        }
+    }
+    else
+        rv = EXR_ERR_SUCCESS; // this part has none, inherits from part 0
+    if (rv != EXR_ERR_SUCCESS)
+        mismatchattr[misidx++] = "colorInteropID";
+
     *mismatchcount = misidx;
     return misidx == 0 ? EXR_ERR_SUCCESS : EXR_ERR_ATTR_TYPE_MISMATCH;
 }