convert tiff image compression lzw to ccitt t.6

[ManthanB]

i am having a tiff file of LZW compression and i wanted to convert the same into CCITT T.6. Is it possible? if sol please give me some advice or sample code about the same. Thanks and regards

[Momerath]

Sure it is. There are plenty of examples of LZW compression if you just search for them. Decompress it, then compress it with CCITT T.6

Search engines are your friend.

[deceptikon]

The System.Windows.Media libraries make this so easy as to be trivial:

public static class ImageProcessing
{
    /// <summary>
    /// Encodes the provided TIFF file with new compression and pixel format.
    /// </summary>
    /// <param name="path">The source TIFF image file.</param>
    /// <param name="compression">Desired TIFF compression.</param>
    /// <param name="format">Desired pixel format.</param>
    /// <remarks>
    /// The original file is overwritten with the result.
    /// </remarks>
    public static void Encode(string path, TiffCompressOption compression, PixelFormat format)
    {
        var decoder = TiffBitmapDecoder.Create(
            new Uri(path),
            BitmapCreateOptions.PreservePixelFormat,
            BitmapCacheOption.OnLoad);
        var encoder = new TiffBitmapEncoder();

        encoder.Compression = compression;
        encoder.Frames.Add(BitmapFrame.Create(SetPixelFormat(decoder.Frames[0], format)));

        using (var stream = new FileStream(path, FileMode.Truncate, FileAccess.Write))
        {
            encoder.Save(stream);
        }
    }

    /// <summary>
    /// Sets the pixel format for an image.
    /// </summary>
    /// <param name="image">The original image.</param>
    /// <param name="pixelFormat">The desired pixel format.</param>
    /// <returns>The image converted ot the desired pixel format.</returns>
    private static BitmapSource SetPixelFormat(BitmapSource image, PixelFormat format)
    {
        var formatted = new FormatConvertedBitmap();

        formatted.BeginInit();
        formatted.Source = image;
        formatted.DestinationFormat = format;
        formatted.EndInit();

        return formatted;
    }
}

Just call that function like this:

ImageProcessing.Encode("myfile.tif", TiffCompressOption.Ccitt4, PixelFormats.BlackWhite);

Easy peasy. :) Some things are hard with that library, but dicking around with the compression and pixel format of a TIFF is a no brainer.