public static (Image image, ImageMetadata metadata) ExtractCurrentFrame(Tiff tiff)
{
// read image properties
int width = GetTagInt32(TiffTag.IMAGEWIDTH, null);
int height = GetTagInt32(TiffTag.IMAGELENGTH, null);
int samplesPerPixel = GetTagInt32(TiffTag.SAMPLESPERPIXEL, 1);
int bitsPerSample = GetTagInt32(TiffTag.BITSPERSAMPLE, 1);
int xres = GetTagInt32(TiffTag.XRESOLUTION, 200);
int yres = GetTagInt32(TiffTag.YRESOLUTION, 200);
int photometric = GetTagInt32(TiffTag.PHOTOMETRIC, (int)TIFFPhotometricInterpretation.WhiteIsZero);
Image image = null;
if (photometric == (int)TIFFPhotometricInterpretation.YCbCr)
{
// special case for YCbCr photometric - read image as rgba
image = new Image(width, height, 32, xres, yres);
int imageSize = height * width;
int[] buffer = new int[imageSize];
// Read the image into the memory buffer
if (tiff.ReadRGBAImageOriented(width, height, buffer, Orientation.TOPLEFT))
{
unsafe
{
fixed(int *src = buffer)
{
fixed(ulong *dst = image.Bits)
{
Arrays.CopyStrides(image.Height, new IntPtr(src), width * sizeof(int), new IntPtr(dst), image.Stride8);
}
}
}
}
}
else
{
image = new Image(width, height, samplesPerPixel * bitsPerSample, xres, yres);
// read bytes
int scanlineSize = tiff.ScanlineSize();
byte[] buffer = new byte[Math.Max(scanlineSize, image.Stride8)];
for (int i = 0, offdst = 0; i < height; i++, offdst += image.Stride)
{
if (!tiff.ReadScanline(buffer, 0, i, 0))
{
throw new InvalidOperationException(Properties.Resources.E_CannotDecodeImage);
}
if (image.BitsPerPixel < 8)
{
unsafe
{
fixed(ulong *dst = &image.Bits[offdst])
{
fixed(byte *src = buffer)
{
Vectors.SwapBits(image.Stride, (ulong *)src, image.BitsPerPixel, dst);
}
}
}
}
else
{
Buffer.BlockCopy(buffer, 0, image.Bits, offdst, image.Stride8);
}
}
}
// read all set tags
ImageMetadata metadata = new ImageMetadata();
foreach (TiffFieldInfo fip in tiff.EnumFieldInfo(TiffType.ANY))
{
object value = GetTag(fip);
if (value != null)
{
metadata.SetPropertyItem((int)fip.Tag, value);
}
}
return(image, metadata);
int GetTagInt32(TiffTag tag, int?defaultValue)
{
FieldValue[] values = tiff.GetField(tag);
if (values != null && values.Length > 0)
{
return(values[0].ToInt());
}
if (!defaultValue.HasValue)
{
throw new InvalidOperationException();
}
return(defaultValue.Value);
}
object GetTag(TiffFieldInfo fip)
{
object convertedValue = null;
if (CanLoadTag((int)fip.Tag))
{
FieldValue[] value = tiff.GetField(fip.Tag);
if (value != null && value.Length > 0)
{
try
{
if (value.Length == 1)
{
convertedValue = ConvertFieldValue(fip.Type, value[0]);
}
else if (value.Length == 2 && fip.PassCount)
{
convertedValue = ConvertFieldValue(fip.Type, value[1]);
}
else
{
convertedValue = CastFieldValues(fip.Type, value.Select(x => ConvertFieldValue(fip.Type, x)).ToArray());
}
}
catch
{
}
}
}
return(convertedValue);
bool CanLoadTag(int id)
{
if (id == (int)TIFFField.RowsPerStrip ||
id == (int)TIFFField.StripByteCounts ||
id == (int)TIFFField.StripOffsets ||
id == (int)TIFFField.TileByteCounts ||
id == (int)TIFFField.TileOffsets)
{
return(false);
}
return(true);
}
object ConvertFieldValue(TiffType type, FieldValue value)
{
switch (type)
{
case TiffType.BYTE:
return(value.Value is Array ? (object)value.ToByteArray() : value.ToByte());
case TiffType.SBYTE:
return(value.Value is Array ? (object)value.ToSByteArray() : value.ToSByte());
case TiffType.SHORT:
return(value.Value is Array ? (object)value.ToUShortArray() : value.ToUShort());
case TiffType.SSHORT:
return(value.Value is Array ? (object)value.ToShortArray() : value.ToShort());
case TiffType.LONG:
case TiffType.IFD:
return(value.Value is Array ? (object)value.ToUIntArray() : value.ToUInt());
case TiffType.SLONG:
return(value.Value is Array ? (object)value.ToIntArray() : value.ToInt());
case TiffType.LONG8:
case TiffType.IFD8:
case TiffType.SLONG8:
return(value.Value is Array ? (object)value.TolongArray() : value.ToLong());
case TiffType.RATIONAL:
case TiffType.SRATIONAL:
case TiffType.FLOAT:
return(value.Value is Array ? (object)value.ToFloatArray() : value.ToFloat());
case TiffType.DOUBLE:
return(value.Value is Array ? (object)value.ToDoubleArray() : value.ToDouble());
case TiffType.ASCII:
if (value.Value is byte[])
{
return(Encoding.GetEncoding("Latin1").GetString(value.Value as byte[]).TrimEnd(new[] { '\0' }));
}
else
{
return(Convert.ToString(value, CultureInfo.InvariantCulture));
}
default:
return(value.ToString());
}
}
object CastFieldValues(TiffType type, object[] values)
{
switch (type)
{
case TiffType.BYTE:
return(Cast <byte>());
case TiffType.SBYTE:
return(Cast <sbyte>());
case TiffType.SHORT:
return(Cast <ushort>());
case TiffType.SSHORT:
return(Cast <short>());
case TiffType.LONG:
case TiffType.IFD:
return(Cast <uint>());
case TiffType.SLONG:
return(Cast <int>());
case TiffType.LONG8:
case TiffType.IFD8:
return(Cast <ulong>());
case TiffType.SLONG8:
return(Cast <long>());
case TiffType.RATIONAL:
case TiffType.SRATIONAL:
case TiffType.FLOAT:
return(Cast <float>());
case TiffType.DOUBLE:
return(Cast <double>());
case TiffType.ASCII:
return(Cast <string>());
default:
return(values);
}
object Cast <T>()
{
return(values.All(x => x is T) ? (object)values.Cast <T>().ToArray() : values);
}
}
}
}
