Archived:Problems Viewing Saved Images in Third Party Software

Updated Feb 2, 2018

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Reported In

Driver

  • NI-IMAQ
  • NI-IMAQdx

Issue Details

I am trying to view images in 3rd party imaging software (Adobe, etc.) and I am not seeing what I expect. What are some common problems and their solutions?

Solution

The following are some common issues associated with saving images in Vision and opening them in 3rd party software:
 
  • When opening 12 bit images in an external viewer that were saved by Vision, the image is mostly gray and does not appear correctly:
    • When IMAQ Vision displays a 16 bit image in the default mode, it looks at the dynamic range of the image and scales the dynamic range to an 8 bit range before displaying it. Photoshop and other external viewers just take the 16 bit data, shift it right by 8 bits, and then display the resulting image. So, if you had a 10 bit image, you will get only 2 bits of resolution and your image would look black.
    • For example, a pixel that is saved in Vision which has data such as 0000111111111111 will be displayed in the third party viewer as 00001111. To correct for this, we need to shift the data by 8 bits (multiply by 64) so the most significant data from the Vision 12 bit image matches up with the most significant bits of the 8 bits displayed. An eight bit shift of the array would give 1111111100000000. And as a result, the displayed portion would be 11111111 and the 00000000, since it is least significant, would not matter to the viewer. You can reference the attached VI (Bit Shift 12bit Image and Resave.vi) for more information.
 
  • My Overlay Does Not Appear In My Third Party Viewer
    • When using the IMAQ Overlay functions a third party viewer will not display this information. You must use the Read Image Vision Info with application software to view the overlay. To display an overlay in a third party viewer you can use the IMAQ Merge Overlay.vi which is a destructive function which replaces the underlying pixels with the overlayed pixels.

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