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I can't get opencv to work at all

  • October 6, 2021
  • 1 reply
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michiedem
Contributor
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I want to try openCV, but I get completely stuck with no real error message at all. I tried a lot of different approaches, but even the simplest doesn't work whatsoever.

 

Workflow for the simplest:

Use the openCV comandline to mark positive samples and generate an annotation file. To make it as simple as possible, I tried 1 positive sample, resulting in this annotations file:

 

F:\\temp\\opencv\\positives\\0.png 1 45 35 38 63

 

Next I made a folder containing negatives with 20 negatives (tried .png and.tif)

 

Next up is the samplepreparer:

negatives: use existing (tred overwrite too)

 

positives:

number of samples: 1

width/hight 200 and 200 (tried numorous different values)

 

I allocate a negatives and vec file location and that's it. No spaces in anny of the folder structures.

 

I get rejected features.

 

Storing feature(s) to FME feature store file `F:\\fmetemp\\wb-cache--PkosFd\\Main_RasterObjectDetectorSamplePrepar -1 19 fo 1 _lt_REJECTED_gt_ 0 9db0cf751f86d66944dfbb4c75f54d358bd7f17d.ffsupdating'

Creator_CREATED_-1_20_Player (RecorderFactory): Played back 1 feature(s) from file `F:\\fmetemp\\wb-cache--PkosFd\\Main_Creator -1 15 fo 0 CREATED 0 11b5656fcc71b159fce42912dc7f3f1439c50cdd.ffs'

 

 

I tried the samplegenerator in an even simpler way:

1 negative image (.jpg)

of course 1 postive (.jpg)

DIfferent width and height settings. different numbers of output. Tried it all and it all results in rejected without an error message,

 

 

1 reply

michiedem
Contributor
Forum|alt.badge.img+7
  • Author
  • Contributor
  • October 6, 2021

for future reference: it tuns out opencv does not like absolute paths as you can aslo read here: https://community.safe.com/s/question/0D54Q000080hfHhSAI/rasterobjectdetector-sample-preparer

 

The new problem is that the output just doesn't make sense at all, not even with a much higher amount of positives and negatives. I use cars on aereal photo's as possitives. The results out of OpenCV are much larger (city blocks)


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