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Image control and Image probe bug or normal behavior?


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If I display an U16 or I16 or SGL image using probe or display control, it shows pitch black for any value (they all should span 0-U16 max for U16 and SGL and 0-I16max for I16, I think), if all image pixels have the same value.

 

Is this a bug or expected behavior? It doesn't happen with U8 image tho...

Edited by bublina
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It's been a while since I've used Vision but I remember seeing some weird things with the higher bit depth images. I remember that sometimes you had to explicitly set the bit depth of the image:

http://zone.ni.com/reference/en-XX/help/370281P-01/imaqvision/imaq_image_bit_depth/

 

What pixel values are in your image? Could they just be really low? I'm guessing the gradient or rainbow pallets aren't helping

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  • 4 weeks later...

If I display an U16 or I16 or SGL image using probe or display control, it shows pitch black for any value (they all should span 0-U16 max for U16 and SGL and 0-I16max for I16, I think), if all image pixels have the same value.

 

Is this a bug or expected behavior? It doesn't happen with U8 image tho...

 

Why do graphs have autoscaling on their axis? The IMAQ Vision control has the same for the range. Certainly not a bug but sometimes not what you expect. If you show the Image Information you also see the range that the image currently uses. And you can change that directly in there or through properties. 

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Why do graphs have autoscaling on their axis? The IMAQ Vision control has the same for the range. Certainly not a bug but sometimes not what you expect. If you show the Image Information you also see the range that the image currently uses. And you can change that directly in there or through properties. 

 

It has nothing to do with range. It is about the bit depth like Infinitenothing posted.

 

Which is sort of like range. But you can only set it to discrete values (just like setting the image type), so you see the confusion. It also results in odd behavior, since the pixel depth is somehow pixel calculated, so one time 2^14 is gray, and other time it is black.

 

Not something, that can happen with real images, but during development, some probe images can make your head spin.

 

May the attached VI help explain myself.

ImageBitDepth.vi

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