I would like to process individual images from one column sequentially, so basically to loop over the raw of this column, so that I can apply the same processing with openCV/Python (actually to do a matchTemplate)
I though about using the "Table Raw to Variable" node to recover the image as a flow variable in the Python node, but the data type of the generated flow variable seems to be a unicode string that contains the information about the image (like when the renderer is set to multi-line string in the data viewer).
Any suggestion ?
In general you can just use the Chunk Loop Start and Loop End nodes to create a loop to process rows one by one.
I recommend you take a look at the KNIP Python Extension though, they allow you to directly process your images with Python in KNIME.
Thanks a lot for introducing KNIP ! I will try that ASAP