Problem encoding TIFF, the compression is always LZW

Question

Hi, I'm trying to encode a Bitmap array to a multipage TIFF.
The Bitmaps are 1 bit depth (verified), I force the CCITT4compression, but the result is always LZW compression.

The code:

Bitmap[] IncomingArray;
MemoryStream _stream = new MemoryStream();
Image TempImage;

Encoder myEncoder = Encoder.SaveFlag;

ImageCodecInfo infoEncoder = GetEncoderInf(ImageFormat.Tiff);
            foreach (ImageCodecInfo ici in ImageCodecInfo.GetImageEncoders())
                if (ici.MimeType == "image/tiff")
                    infoEncoder = ici;
            
EncoderParameters myEncoderParameters = new EncoderParameters(2);
myEncoderParameters.Param[0] = new EncoderParameter(myEncoder, (long)EncoderValue.MultiFrame);
myEncoderParameters.Param[1] = new EncoderParameter(myEncoder, (long)EncoderValue.CompressionCCITT4);
        
TempImage = (Image)IncomingArray[0];
            
TempImage.Save(_stream, infoEncoder, myEncoderParameters);
            
            if (IncomingArray.Length > 1)
            {
                myEncoderParameters.Param[0] = new EncoderParameter(myEncoder, (long)EncoderValue.FrameDimensionPage);

for (int iCount = 1; iCount < IncomingArray.Length; iCount++)
                {
                    TempImage.SaveAdd((Image)IncomingArray[iCount], myEncoderParameters);
                }
            }
myEncoderParameters.Param[0] = new EncoderParameter(myEncoder, (long)EncoderValue.Flush);
            TempImage.SaveAdd(myEncoderParameters);

            //_stream.Seek(0, SeekOrigin.Begin);

_stream.Position = 0;
File.WriteAllBytes("c:\\test.tif", _stream.ToArray());

Looking at tags, test.tif is 1 bit depth, but is encoded LZW...

If the image is 1 bit depth, why it isn't compressed CCITT4 ?

 

Answer 1

Solved !

Simply changed:
myEncoderParameters.Param[1] = new EncoderParameter(myEncoder, (long)EncoderValue.CompressionCCITT4);

with:
myEncoderParameters.Param[1] = new EncoderParameter(System.Drawing.Imaging.Encoder.Compression, (long)EncoderValue.CompressionCCITT4);

The compression type works only if associated to the right Encoder.