Knowledgebase: Syngene
Captured TIFF Images Appear Very Dark When Opened With an External Program
Posted by Keira Davies, Last modified by Keira Davies on 05 January 2016 10:39 AM


When you use an external program to open a TIFF image that was captured and saved using GeneSys or the U:Genius 3 software, the image appears black or very dark even though the original image -- as displayed in the Syngene capture software -- was clear and bright with visible bands.

This problem has been observed in the following external programs:

  • Paintshop Pro X6
  • Microsoft Paint
  • Microsoft Photo Viewer
  • The GIMP 2.8
  • Apple Preview (The built-in, OS X, image viewer)

It's likely that many other programs also exhibit this issue.


This problem is caused by the fact that both the GeneSys and U:Genius 3 software, by default save in a 16 bit, greyscale TIFF image format (.tif file extension) that is not widely understood by third-party, image viewing/editing programs.

Many image viewing/editing programs only understand baseline 8 bit or 4 bit greyscale, TIFF images.

Solution 1: GeneTools

Our GeneTools image analysis software correctly interprets the 16 bit TIFF images produced by the GeneSys and U:Genius 3 software.  We recommend you view and analyses the images using GeneTools.

Solution 2: Save as 8 bit (U:Genius 3 only)

When you save an image to disk using a U:Genius 3, the "Save As" dialogue contains a tickbox labelled "Convert to 8 bit data". If you check this tickbox, a TIFF file will be produced that is widely understood by and compatible with third-party image viewers/editors.

Please note: if you save your images in 8 bit format, you are losing some precision.  This may be fine for the purpose of superficial presentations of your data, but for image analysis (as performed in GeneTools), it is better to work with the raw 16 bit image.

Solution 3: The Histogram/Colour Levels Tool

If your image viewer/editor software has a histogram/colour-levels tool, you may be able to use this to tell the software to display the usable greyscale range across the full visible greyscale spectrum.

Below is a demonstration of this process using the The GIMP (GNU Image Manipulation Program):

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