/// <summary>Converts a bitmap to a Tiff with a specific compression</summary>
///
/// <param name="inputBmp">Bitmap to convert</param>
/// <param name="compression">The compression to use on the TIFF file output. Be warned that the CCITT3, CCITT4,
/// and RLE compression options are only applicable to TIFFs using a palette index color depth
/// (that is, 1, 4, or 8 bpp). Using any of these compression schemes with 24 or 32-bit
/// TIFFs will throw an exception from the bowels of GDI+</param>
///
/// <returns>A new bitmap object containing the input bitmap converted.
/// If the destination format and the target format are the same, returns
/// a clone of the destination bitmap.</returns>
public static Bitmap ConvertBitmapToTiff(Bitmap inputBmp, TiffCompressionEnum compression)
{
//If the dest format matches the source format and quality/bpp not changing, just clone
if (inputBmp.RawFormat.Equals(ImageFormat.Tiff) && compression == TiffCompressionEnum.Unspecified)
{
return((Bitmap)inputBmp.Clone());
}
if (compression == TiffCompressionEnum.Unspecified)
{
//None of the params are chaning; use the general purpose converter
return(ConvertBitmap(inputBmp, ImageFormat.Tiff));
}
//Create an in-memory stream which will be used to save
//the converted image
Stream imgStream = new MemoryStream();
//Get the ImageCodecInfo for the desired target format
ImageCodecInfo destCodec = FindCodecForType(MimeTypeFromImageFormat(ImageFormat.Tiff));
if (destCodec == null)
{
//No codec available for that format
throw new ArgumentException("The requested format " +
MimeTypeFromImageFormat(ImageFormat.Tiff) +
" does not have an available codec installed",
"destFormat");
}
//Create an EncoderParameters collection to contain the
//parameters that control the dest format's encoder
var destEncParams = new EncoderParameters(1);
//set the compression parameter
EncoderValue compressionValue;
switch (compression)
{
case TiffCompressionEnum.CCITT3:
compressionValue = EncoderValue.CompressionCCITT3;
break;
case TiffCompressionEnum.CCITT4:
compressionValue = EncoderValue.CompressionCCITT4;
break;
case TiffCompressionEnum.LZW:
compressionValue = EncoderValue.CompressionLZW;
break;
case TiffCompressionEnum.RLE:
compressionValue = EncoderValue.CompressionRle;
break;
default:
compressionValue = EncoderValue.CompressionNone;
break;
}
var compressionParam = new EncoderParameter(Encoder.Compression, (long)compressionValue);
destEncParams.Param[0] = compressionParam;
//Save w/ the selected codec and encoder parameters
inputBmp.Save(imgStream, destCodec, destEncParams);
//At this point, imgStream contains the binary form of the
//bitmap in the target format. All that remains is to load it
//into a new bitmap object
var destBitmap = new Bitmap(imgStream);
//Free the stream
//imgStream.Close();
//For some reason, the above causes unhandled GDI+ exceptions
//when destBitmap.Save is called. Perhaps the bitmap object reads
//from the stream asynchronously?
return(destBitmap);
}
/// <summary>Converts a bitmap to a Tiff with a specific compression</summary>
///
/// <param name="inputBmp">Bitmap to convert</param>
/// <param name="compression">The compression to use on the TIFF file output. Be warned that the CCITT3, CCITT4,
/// and RLE compression options are only applicable to TIFFs using a palette index color depth
/// (that is, 1, 4, or 8 bpp). Using any of these compression schemes with 24 or 32-bit
/// TIFFs will throw an exception from the bowels of GDI+</param>
///
/// <returns>A new bitmap object containing the input bitmap converted.
/// If the destination format and the target format are the same, returns
/// a clone of the destination bitmap.</returns>
public static Bitmap ConvertBitmapToTiff(Bitmap inputBmp, TiffCompressionEnum compression)
{
//If the dest format matches the source format and quality/bpp not changing, just clone
if (inputBmp.RawFormat.Equals(ImageFormat.Tiff) && compression == TiffCompressionEnum.Unspecified)
{
return(Bitmap)inputBmp.Clone();
}
if (compression == TiffCompressionEnum.Unspecified)
{
//None of the params are chaning; use the general purpose converter
return ConvertBitmap(inputBmp, ImageFormat.Tiff);
}
//Create an in-memory stream which will be used to save
//the converted image
System.IO.Stream imgStream = new System.IO.MemoryStream();
//Get the ImageCodecInfo for the desired target format
ImageCodecInfo destCodec = FindCodecForType(MimeTypeFromImageFormat(ImageFormat.Tiff));
if (destCodec == null)
{
//No codec available for that format
throw new ArgumentException("The requested format " +
MimeTypeFromImageFormat(ImageFormat.Tiff) +
" does not have an available codec installed",
"destFormat");
}
//Create an EncoderParameters collection to contain the
//parameters that control the dest format's encoder
EncoderParameters destEncParams = new EncoderParameters(1);
//set the compression parameter
EncoderValue compressionValue;
switch (compression)
{
case TiffCompressionEnum.CCITT3:
compressionValue = EncoderValue.CompressionCCITT3;
break;
case TiffCompressionEnum.CCITT4:
compressionValue = EncoderValue.CompressionCCITT4;
break;
case TiffCompressionEnum.LZW:
compressionValue = EncoderValue.CompressionLZW;
break;
case TiffCompressionEnum.RLE:
compressionValue = EncoderValue.CompressionRle;
break;
default:
compressionValue = EncoderValue.CompressionNone;
break;
}
EncoderParameter compressionParam = new EncoderParameter(Encoder.Compression, (long)compressionValue);
destEncParams.Param[0] = compressionParam;
//Save w/ the selected codec and encoder parameters
inputBmp.Save(imgStream, destCodec, destEncParams);
//At this point, imgStream contains the binary form of the
//bitmap in the target format. All that remains is to load it
//into a new bitmap object
Bitmap destBitmap = new Bitmap(imgStream);
//Free the stream
//imgStream.Close();
//For some reason, the above causes unhandled GDI+ exceptions
//when destBitmap.Save is called. Perhaps the bitmap object reads
//from the stream asynchronously?
return destBitmap;
}