Re: [Openexr-devel] OpenEXR colorimetry

[Greg Ward]

Thanks, Joseph, for those insightful comments.  FYI, these are the 
attributes I am currently defining in Photosphere.  I haven't written 
or distributed any significant number of EXR files to date, but I'm not 
sure what others have done.  If any of the following names should 
change, I hope someone will tell me.  Notice that I'm not currently 
storing the primary chromaticities.

        if (wb->info.flags & IIFcapdate)
                hdr->insert("capDate", StringAttribute(wb->info.capdate));
        if (wb->info.flags & IIFgmtoffset)
                hdr->insert("gmtOffset", FloatAttribute(wb->info.gmtoffset));
        if (wb->info.flags & IIFlongitude)
                hdr->insert("longitude", FloatAttribute(wb->info.longitude));
        if (wb->info.flags & IIFlatitude)
                hdr->insert("latitude", FloatAttribute(wb->info.latitude));
        if (wb->info.flags & IIFstonits)
                hdr->insert("sampToNits", FloatAttribute(wb->info.stonits));
        if (wb->info.flags & IIFhdensity)
                hdr->insert("xDensity", FloatAttribute(wb->info.hdensity));
        if (wb->info.flags & IIFexptime)
                hdr->insert("expTime", FloatAttribute(wb->info.exptime));
        if (wb->info.flags & IIFaperture)
                hdr->insert("aperture", FloatAttribute(wb->info.aperture));
        if (wb->info.flags & IIFasa)
                hdr->insert("asa", FloatAttribute(wb->info.asa));
        if (wb->info.flags & IIFfocus)
                hdr->insert("focus", FloatAttribute(wb->info.focus));
        if (wb->info.flags & IIFview)
                hdr->insert("view", StringAttribute(wb->info.view));
        if (wb->info.flags & IIFowner)
                hdr->insert("owner", StringAttribute(wb->info.owner));
        if (wb->info.flags & IIFcomments)
                hdr->insert("comments", StringAttribute(wb->info.comments));

The sampToNits attribute is meant to have the same interpretation and 
value as the TIFFTAG_STONITS tag.

-Greg