about interpolate range

[cemysf]

hello, is there any guide about using the "interpolate range" option?

it sounds useful but I couldn't find anything in the official documentation, also when I try to apply it gives this error:

Error: Annotation count differs in first and last labeled frames, aborting

[nilsonholger]

Nope, sorry, but no documentation (yet). This was a quick hack, and while it's in there already, it's not yet considered mature enough. But your error seems to be very clear IHMO...you're trying to interpolate between two frames with a different number of annotations, which this feature simply can't do, as its linearly interpolating between two given annotation lists, in the order they appear in that list. You can check annotations/model.py for further information.

[nilsonholger]

So, I looked into this a bit further. It seems likely that your problem is caused by multiple issues...the short answer would be "you're using it wrong"...the elaborated answer "it's complicated"...

• unlabeled objects must have "unlabeled": true set (this will also cause a red marker to appear in the GUI, to mark an image as labeled, simply press SPACE)...you can add these by hand or by using sloth appendfiles --unlabeled <labelfile> <image_file1> <image_file2> ... when creating the label file, sadly, using the GUIs Add Image functionality does not consider setting this label (yet, this should be a separate bug report), also the two images your are trying to interpolate between must not be marked as unlabeled
• the interpolate function tries to ensure that your labels are as consistent between the two frames as it possibly can...each attribute must have a class as well as a type to distinguish between different objects of the same type, e.g. add to your config:

  LABELS = (
      {
          'attributes': {
              'type':      'rect',
              'class':     'my_class'
           },
          'inserter': 'sloth.items.RectItemInserter',
          'item':     'sloth.items.RectItem',
          'hotkey':   'b',
          'text':     'Button (near)'
      },
  ...

  so that in your label file you will get:

  ...
  annotations: [
              {
                  class: my_class,
                  type: rect,
  ...

• these labels (with class as well as type) must be in the exact same order, otherwise the function can't work

Hope this helps a bit, again, the interpolate function is not yet mature enough and we definitely need to fix a few things and especially document it, so pull requests welcome!!! (it was published upstream already only because we were asked by multiple sources whether such functionality exists, which it already did, so sorry for the confusion)

[cemysf]

ok, I can use it now it looks like it is working for just one annotation in two files, but it fails with multiple annotations

I will try to fix it, thank you very much for your help