Compressing to CCIT4

[drose]

I am evaluating this software and so far everything has gone well. However, I do not seem to be able to get my multipage tif file to compress into CCITT4 format. Instead, the image always is compressed in LZW format.

Here is my code:

Code: Select all

if (axTwain1.TwainOpenDefaultSource())
            {
                nImageCount = 0;
               
                axTwain1.TwainSetHideUI(true);
                axTwain1.TwainSetAutoFeed(true);
                axTwain1.TwainSetAutoScan(true);
                axTwain1.TwainSetCurrentImageFileFormat(GdTwainPro2.TwainImageFileFormats.TWFF_TIFFMULTI);
                axTwain1.TwainSetCurrentResolution(300);
                axTwain1.TwainSetCurrentPixelType(GdTwainPro2.TwainPixelType.TWPT_BW);
                axTwain1.TwainSetCurrentBitDepth(1);
                axTwain1.ConvertTo1Bpp();
                axTwain1.TwainSetCurrentCompression(GdTwainPro2.TwainCompression.TWCP_GROUP4);

                while (axTwain1.TwainAcquireToGdPictureImage() != 0)
                {
                    nImageID = axTwain1.GetNativeImage();
                    nImageCount = nImageCount + 1;
                    axGdViewer1.DisplayFromGdPictureImage(nImageID);
                    axGdViewer1.SetZoomFitControl();

                    if (nImageCount == 1)
                    {
                        axTwain1.TiffSaveAsNativeMultiPage("C:\\multitiff.tif");
                    }
                    else
                    {
                        axTwain1.TiffAddToNativeMultiPage(nImageID);
                        axTwain1.CloseImage(nImageID);
                    }
                }

                axTwain1.TiffCloseNativeMultiPage();
                axTwain1.TwainCloseSource();

What am I doing wrong?

[drose]

Additionally, I am unable to get it to compress using any other method as well.

[Loïc]

Hi,

You are using the bad syntax.

The TwainSetCurrentImageFileFormat() method should be used only if you are using the file transfer mode.

In your case, you just need to specify the optional compressio parameter of the TiffSaveAsNativeMultiPage() method.

IE:

Code: Select all

axTwain1.TiffSaveAsNativeMultiPage("C:\\multitiff.tif", CompressionCCITT4);

See: http://guides.gdpicture.com/v5/gdtwainp ... iPage.html

Best regards,

Loïc Carrère

[drose]

That did it. Thanks!