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PDF to TIFF Depth and Compression Problem


I am using the Aspose.PDF version, Aspose.Cells version and Aspose.Words version

I am trying to convert the PDF document to Tiff image.
The tiff Image that is produced has 32 bpp and Compresion LZW.
Because I need a grayscale tiff image to be produced.
I am using the following code snippet:

var tiffSettings=new TiffSettings();
tiffSettings.Compression= CompressionType.CCITT4;
tiffSettings.Depth= ColorDepth.Format1bpp;

But still the image that is produced with 32 bpp and Compression LZW.
I have attached the TIFF file(TIFF1.tif) that is produced from TIFF1.pdf(also attached)

How can I obtain the tiff image produced reduced to 1bpp but with 2200* 1700 resolution.

Please advice.


Hi Jess,

Thanks for contacting support.

I have tested the scenario using Aspose.Pdf for .NET 8.1.0 over Windows 7 (X64) in Visual Studio 2010 application and I am unable to notice any issue. I have used following code snippet to convert PDF file to TIFF format.


//open document<o:p></o:p>

Document pdfDocument = new Document("c:/TIFF1.PDF");

//create Resolution object

Resolution resolution = new Resolution(300);

resolution.X = 2200;

resolution.Y = 1700;

//create TiffSettings object

TiffSettings tiffSettings = new TiffSettings();

tiffSettings.Compression = CompressionType.CCITT4;

tiffSettings.Depth = Aspose.Pdf.Devices.ColorDepth.Format1bpp;

tiffSettings.SkipBlankPages = false;

//create TIFF device

TiffDevice tiffDevice = new TiffDevice(resolution, tiffSettings);

//convert a particular page and save the image to stream

tiffDevice.Process(pdfDocument, “c:/TIFF1_Converted.tif”);

I have used the following code to determine the Compression and color depth information of TIFF image.


// load TIFF image<o:p></o:p>

System.Drawing.Image image = System.Drawing.Image.FromFile("c:/pdftest/TIFF1_Converted.tif");

int compressionTagIndex = Array.IndexOf(image.PropertyIdList, 0x103);

System.Drawing.Imaging.PropertyItem compressionTag = image.PropertyItems[compressionTagIndex];

// detemine the compression type

Console.WriteLine("Compression type = "+ BitConverter.ToInt16(compressionTag.Value, 0));

// check the color depth information

Depth = "
+ image.PixelFormat);

The following list specifies values of compression type:

1: no compression
2: CCITT Group 3
3: Facsimile-compatible CCITT Group 3
4: CCITT Group 4 (T.6)
5: LZW

In console I am getting

  • Compression type = 4
  • Color Depth = Format1bppIndexed