Machine Vision

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IMAQ Vision Info VIs have misleading and undocumented parameters


Windows 8.1
LabVIEW 2018 SP1 f4
Vision Development Module 2018-2019 SP1


Steps to Reproduce:

  1. Create a new VI (or see attached);
  2. Read an image and learn some Pyramid pattern matching template on it using IMAQ Learn Pattern 6 VI;
  3. Place an IMAQ Is Vision Info Present 2 VI on a BD and wire the template image to it;
  4. Create a constant for Vision Info terminal and select Grayscale Template item;
  5. Create an indicator for Present? terminal;
  6. Run the VI.

Expected Result:

According to VI reference:

Grayscale Template (3): Checks if any grayscale pattern matching template information is associated with the image.

So it's expected that Present? will return True.


Actual Result:

Present? returns False.

However, it returns True for Low Discrepancy Sampling template (only):


and Vision Info typedef contains more values than VI reference.

So it looks like Grayscale Template actually mean LD Sampling Template.


The same problems exist for IMAQ Remove Vision Info 2 VI.



Vision Info Type2 typedef items and documentation need clarifications and updating.


Reported to NI with SR #7810065.

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NI Technical Support wrote:

CAR 1077286 created.


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