How to input files from one folder, process them, and save to another folder?

How would I do image processing in bulk — fetch each image from a folder, apply some filter/effect to each image, and save the resulting images to a different folder?

Here are two ways. One or the other might work better depending on the situation.

ProcessImageFiles-LoadAllOnStart.vuo — This composition brings the images into the composition with List Files -> Fetch List of Images. This is convenient if you want to load all of the images when the composition starts and do something with them immediately (such as display them in a grid), and maybe later apply effects and save them to files. This composition uses Build List because it needs to use the output of both List Files and Fetch List of Images in the loop, but if you didn’t need to use file names, you could more simply do Fetch List of Images -> Process List.

ProcessImageFiles-LoadOneAtATime.vuo — This composition loads the images one at a time in the Process List loop using Fetch Image. This uses less memory than the previous composition, making it a better choice if you need to process a lot of large images.

ProcessImageFiles-LoadAllOnStart.vuo (6.63 KB)

ProcessImageFiles-LoadOneAtATime.vuo (4.88 KB)

Exciting! As this can open up Vuo to automation tasks! Can Vuo apps function like droplets? Can we drop files or folders onto apps and have thoses files processed by the app?

Vuo apps can’t function as droplets yet (being able to drop onto the app icon), although if you wanted to make a feature request, it would be only 1-dot complexity. Currently you can drop files or folders onto already-launched Vuo apps using the Receive File Drags node.