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GetVariable("BLOB_COUNT") returns null
Stephen Hewitson from United Kingdom [6 posts] |
9 year
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Hi,
I am trying to use BLOB_COUNT with filters to check that there is nothing of a certain colour, but this appears to return null if there are 0 blobs.
What can I do to determine if 0 blobs have been detected. I don't want to check for null, as the value would be null if there was a comms issue too and I want to differentiate between the two.
Thanks,
Stephen
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Steven Gentner from United States [1446 posts] |
9 year
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Stephen,
because null is essentially the same thing as zero you could also check how many blobs are doing into the module prior to filtering. To do this, we just added a
BLOB_FILTER_START_COUNT
which if zero, means there are no blobs to be filtered and thus might be an indication of a failed camera image, etc.
So use a GetVariable on that, check that it is not zero and then use the BLOB_COUNT as needed. Note we also added a BLOB_FILTER_END_COUNT which is the same as BLOB_COUNT just to have some naming consistency (we can't remove BLOB_COUNT without breaking many other scripts).
Latest version has this update.
STeven.
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