I'm currently finishing a Java data structures class and beginning a Python one, albeit one with Jython lessons, which gives me a nice opportunity to neatly juxtapose the two languages.
Studying JPG, GIF, TIFF, PNG, BMP and learning when to use each one was very useful. It was interesting to read that JPG is the format of choice on the internet due to its excellent quality even at rather high compression settings. It seems not to be lossless, or, rather, it is lossy, but it does discard information that the eye is least likely to notice.
Manipulating digitized image's pixels with code on JES was pretty fun. I had only used software programs to do such in the past. Thanks to CSUMB, I currently possess an Adobe Creative Cloud Membership, so I also took some time to explore the Photoshop app's tools and features for manipulating images, which was decidedly more difficult than writing similarly behaving code on JES! I definitely preferred making my own methods!