Any great workflows or apps for compressing images (png, gif, jpg) on iOS? On the Mac, I use ImageOptim, which is perfectly simple & powerful—drag an image file (or multiple files) into the window and it’ll shrink everything down in place. I’d like to do this on my iPad Pro as well.
I found this Siri Shortcut which does the job, but relies on a third-party API and takes longer because of that. I’d like to do this on device, and seeing how powerful the 2018 iPad Pro is, should be no problem computationally.
ImageOptim looks to be primarily tweaking the content to optimise against the file format compression algorithms rather than just outright changing the compression/quality level to simply reduce the size of the resulting image.
At this tme, I think using an API is still going to give you the best results, or at least farming the images out to ImageOptim on your Mac; but I can appreciate wanting to make the most of your iPad Pro’s processing capabilities.
To that end, there is this option that you might want to take a look at:
The documentation notes that it is compatible with Pythonista 3 and in the how to use section, it does describe the sorts of techniques it employs to reduce the image size. Some aspects can involve lossy compression - but it does try to dynamically determine the best level to apply, and you can always change the settings.