Process images in a folder one at a time?

Hello all,

I am learning how to use KNIME in my image processing workflows, and while I’ve managed to write a few working image processing workflows, I am running into memory issues as I’m trying to process a folder containing multiple raw images that are about 1.9 GB. Even after adjusting my java heap space via editing the knime.ini file, this remains an issue.

One of the basic workflows I’ve written is one that downsizes (using Image Resizer) images in a folder, and then writes them (using Image Writer) to a different directory.

From other posts that I’ve searched through, it seems like it is possible to process images in “chunks” of one or two images using “Chunk Loop Start” in a workflow, and writing the downsized files sequentially in a different output directory. However, I haven’t yet found a clear explanation on how to use these kinds of loops within image processing workflows using a recent version of KNIME (4.6.0) and from a beginner’s perspective. If someone could either point me in the right direction to the right forum post, or help me with this issue, I would be very grateful.


@KT_Wakabayashi welcome to the knime forum. You could indeed process one image at a time. You could list them and then process them in loops.

I often like to use the Table Row to variable loop start node to do things in iterations (Write multiple CSV file to a loop - #2 by mlauber71)

Maybe also interesting:

KNIME’s Flow Control Guide KNIME Flow Control Guide

@armingrudd articles about loops and flow variables How to include file CSV Writer in a loop? - #2 by armingrudd