private static Dictionary <MetadataSection, Dictionary <ushort, MetadataEntry> > CreateTagDictionary(
Document doc,
IDictionary <MetadataKey, MetadataEntry> entries,
ExifColorSpace exifColorSpace)
{
Dictionary <MetadataSection, Dictionary <ushort, MetadataEntry> > metadataEntries = new Dictionary <MetadataSection, Dictionary <ushort, MetadataEntry> >
{
{
MetadataSection.Image,
new Dictionary <ushort, MetadataEntry>
{
{
MetadataKeys.Image.Orientation.TagId,
new MetadataEntry(MetadataKeys.Image.Orientation,
TagDataType.Short,
MetadataHelpers.EncodeShort(TiffConstants.Orientation.TopLeft))
}
}
},
{
MetadataSection.Exif,
new Dictionary <ushort, MetadataEntry>()
}
};
// Add the image size tags.
if (IsUncompressedImage(entries))
{
Dictionary <ushort, MetadataEntry> imageSection = metadataEntries[MetadataSection.Image];
imageSection.Add(MetadataKeys.Image.ImageWidth.TagId,
new MetadataEntry(MetadataKeys.Image.ImageWidth,
TagDataType.Long,
MetadataHelpers.EncodeLong((uint)doc.Width)));
imageSection.Add(MetadataKeys.Image.ImageLength.TagId,
new MetadataEntry(MetadataKeys.Image.ImageLength,
TagDataType.Long,
MetadataHelpers.EncodeLong((uint)doc.Height)));
entries.Remove(MetadataKeys.Image.ImageWidth);
entries.Remove(MetadataKeys.Image.ImageLength);
// These tags should not be included in uncompressed images.
entries.Remove(MetadataKeys.Exif.PixelXDimension);
entries.Remove(MetadataKeys.Exif.PixelYDimension);
}
else
{
Dictionary <ushort, MetadataEntry> exifSection = metadataEntries[MetadataSection.Exif];
exifSection.Add(MetadataKeys.Exif.PixelXDimension.TagId,
new MetadataEntry(MetadataKeys.Exif.PixelXDimension,
TagDataType.Long,
MetadataHelpers.EncodeLong((uint)doc.Width)));
exifSection.Add(MetadataKeys.Exif.PixelYDimension.TagId,
new MetadataEntry(MetadataKeys.Exif.PixelYDimension,
TagDataType.Long,
MetadataHelpers.EncodeLong((uint)doc.Height)));
entries.Remove(MetadataKeys.Exif.PixelXDimension);
entries.Remove(MetadataKeys.Exif.PixelYDimension);
// These tags should not be included in compressed images.
entries.Remove(MetadataKeys.Image.ImageWidth);
entries.Remove(MetadataKeys.Image.ImageLength);
}
// Add the EXIF color space tag.
if (!entries.ContainsKey(MetadataKeys.Exif.ColorSpace))
{
metadataEntries[MetadataSection.Exif].Add(MetadataKeys.Exif.ColorSpace.TagId,
new MetadataEntry(MetadataKeys.Exif.ColorSpace,
TagDataType.Short,
MetadataHelpers.EncodeShort((ushort)exifColorSpace)));
}
foreach (KeyValuePair <MetadataKey, MetadataEntry> kvp in entries)
{
MetadataEntry entry = kvp.Value;
MetadataSection section = entry.Section;
if (section == MetadataSection.Image && !ExifTagHelper.CanWriteImageSectionTag(entry.TagId))
{
continue;
}
if (metadataEntries.TryGetValue(section, out Dictionary <ushort, MetadataEntry> values))
{
if (!values.ContainsKey(entry.TagId))
{
values.Add(entry.TagId, entry);
}
}
else
{
metadataEntries.Add(section, new Dictionary <ushort, MetadataEntry>
{
{ entry.TagId, entry }
});
}
}
AddVersionEntries(ref metadataEntries);
return(metadataEntries);
}
private static IFDEntryInfo CreateIFDList(Dictionary <ushort, MetadataEntry> tags, long startOffset)
{
List <IFDEntry> ifdEntries = new List <IFDEntry>(tags.Count);
// Leave room for the tag count, tags and next IFD offset.
long ifdDataOffset = startOffset + sizeof(ushort) + ((long)tags.Count * IFDEntry.SizeOf) + sizeof(uint);
foreach (KeyValuePair <ushort, MetadataEntry> item in tags.OrderBy(i => i.Key))
{
MetadataEntry entry = item.Value;
uint count;
switch (entry.Type)
{
case TagDataType.Byte:
case TagDataType.Ascii:
case TagDataType.SByte:
case TagDataType.Undefined:
count = (uint)entry.LengthInBytes;
break;
case TagDataType.Short:
case TagDataType.SShort:
count = (uint)entry.LengthInBytes / 2;
break;
case TagDataType.Long:
case TagDataType.SLong:
case TagDataType.Float:
count = (uint)entry.LengthInBytes / 4;
break;
case TagDataType.Rational:
case TagDataType.SRational:
case TagDataType.Double:
count = (uint)entry.LengthInBytes / 8;
break;
default:
throw new InvalidOperationException("Unexpected tag type.");
}
if (TagDataTypeUtil.ValueFitsInOffsetField(entry.Type, count))
{
uint packedOffset = 0;
// Some applications may write EXIF fields with a count of zero.
// See https://github.com/0xC0000054/pdn-webp/issues/6.
if (count > 0)
{
byte[] data = entry.GetDataReadOnly();
// The data is always in little-endian byte order.
switch (data.Length)
{
case 1:
packedOffset |= data[0];
break;
case 2:
packedOffset |= data[0];
packedOffset |= (uint)data[1] << 8;
break;
case 3:
packedOffset |= data[0];
packedOffset |= (uint)data[1] << 8;
packedOffset |= (uint)data[2] << 16;
break;
case 4:
packedOffset |= data[0];
packedOffset |= (uint)data[1] << 8;
packedOffset |= (uint)data[2] << 16;
packedOffset |= (uint)data[3] << 24;
break;
default:
throw new InvalidOperationException("data.Length must be in the range of [1-4].");
}
}
ifdEntries.Add(new IFDEntry(entry.TagId, entry.Type, count, packedOffset));
}
else
{
ifdEntries.Add(new IFDEntry(entry.TagId, entry.Type, count, (uint)ifdDataOffset));
ifdDataOffset += entry.LengthInBytes;
// The IFD offsets must begin on a WORD boundary.
if ((ifdDataOffset & 1) == 1)
{
ifdDataOffset++;
}
}
}
return(new IFDEntryInfo(ifdEntries, startOffset, ifdDataOffset));
}
