I've been playing around with the image processing nodes for the first time today and they look quite exciting, thank you for the great work!
I'm currently simply trying to extract features for a big collection of images. My simplified workflow looks like this:
- Table with image paths
- Chunk Loop Start
- Image Reader (Table)
- Image Cropper (to get R/G/B channels)
- Image Features
- Loop end
Note that the result which is collected by the "Loop End" node does not contain any image cells, but only a bunch of numeric features. The mentioned workflow was running for a while and then suddenly failed with an exception stating "Too many open files". I checked for open files on the system and noticed that all of the processed image files from the dataset so far (8000+) were still open by KNIME (lsof | grep 'train_photos' | wc). (even when closing the workflow, the files remain open).
Is there anything I'm missing here? Do I need to close images manually?
 Potentially related to this issue?
[edit2] Most recent KNIME 3.1 on Mac OS X 10.11.3