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Forcing document conversion via TCDCLink instead of TCIMGIO




Per default specific graphic formats (PNG, GIF, JPG etc.) are converted using the TCIMGIO. Conversion jobs which are performed that way may experience some problems during the image rendering. Depending on the needs of the customer we can manipulate which converter should be triggered for converting these types of files.

To get a better overview we will list the biggest advantages and disadvantages for using the TCDCLink instead of the TCIMGIO.

Advantages for using the TCDCLink:

  • Better image rendering (TCIMGIO only supports B/W conversion).
  • More flexible, since it is controlled by the 'Shell Execute Printing'.

Disadvantages for using the TCDCLink:

  • Slower performance.
  • Multi-page files (E.g. Tif) can't be converted.

Let's show in an example why the option to force the Document Conversion via TCDCLink can be important for some customers.

Example: A simple example shows us the difference between the two converters. The attached image originally was a colored JPEG which was faxed out via the TC/Link-SM.

Original Colored JPEG which will be faxed out:

Screen Shot 2018-07-24 at 3.25.58 PM.png

Converted and faxed out colored JPEG using the TCIMGIO:

Screen Shot 2018-07-24 at 3.29.40 PM.png

Converted and faxed out colored JPEG using the TCDCLink:

Screen Shot 2018-07-24 at 4.01.58 PM.png

In this example we can see that using the TCDCLink for image conversion can provide much better results. Note the disadvantage of slower performance. It can easily happen that colored JPEGs with a resolution of 300x300 lose a lot of crucial data when converted to B/W images using the TCIMGIO.

The decision which document conversion method should be used depends on the customer requirements. If the customer faxes out files from different graphic formats (JPEG, TIF, PNG, GIF etc.) and those images don't contain a wide color spectrum or are multi-paged (multi-page TIF), then it is suggested to use the TCIMGIO.

If the customer sends colored graphics similar to the example image, then it is strongly recommended to use the TCDCLink instead of the TCIMGIO, to get better looking results.

How to force the document conversion through the TCDCLink:

In a few steps we will demonstrate what is needed to render the graphic files through the TCDCLink.

  1. Start the registry editor and navigate to this key: (this is needed for enabling gray-scaling)
        HKLM\System\CurrentControlSet\Control\Print\Printers\Topcall Fax to
        TCDC\PrinterDriverData\'halftonedither' = 1
  2. Navigate to the folder: C:\TCOSS\TCLP\script\ and make sure there is no script inside the folder which is named like the file extension which should be converted (E.g. no 'JPEG.txt' for JPEG files)
  3. Depending on the message flow, check the TCIMGIO32 settings of the involved TC/Link instance and set the 'InputExtensions' key for 'jpg' to empty.
    To do that please check the key:
    (This is an example for the file extension: JPG. For other graphic file extensions use the related 'FmtXXX' folder - for GIF use the 'FmtGIF', for BMP the 'FmtBMP' etc.)
  4. Install IrfanView (it is a freeware Image Viewer; but for commercial use a small license-fee is required!)
  5. Navigate to the shell execute of the TCDCLink and add the JPG extension.
    To do that go to the folder inside of the registry:
    In this folder please create a REG_SZ key named '.jpg' (or any other graphic file extension which is involved in the message flow) with the value:
         'C:\Program Files\IrfanView\i_view32.exe' '%1' /bpp=1 /print'
  6. After those changes please restart the involved TC/Link & TCDCLink and send a fax message. The document conversion and image rendering will now be done by the TCDCLink.

Notes for x64:

For x64 systems the Topcall registry key can be found here:

IrfanView will be installed in the following folder:
    C:\Program Files (x86)\IrfanView

What was done?

We have setup the TCDCLink instead of the TCIMGIO for converting jpg files (by changing the 'InputExtensions'), and we added the shell execute print command for IrfanView. By using the command line command: '/bpp=1' we convert the colored jpg into a gray-scale jpg and from there it's sent to the TCDCLink.

Applies to

  • TC/LP - all supported versions

Keywords: IrfanViewGrayscale, greyscale, gray, greyImage, JPG, JPEG, TIF, TIFF, PNG, GIFRenderingTCDC

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