Many image file formats exist, but which ones are better for what task? Here is a quick overview in my little series of PhD advice blog posts (the previous being tips on dissertation writing and the public PhD defense). Two different image types When choosing a file format for your image, the first thing is to figure out whether you are dealing with a raster image (photos) or a vector image (line illustrations).

I have previously written about how to resize all the images in a folder. That script was based on lossy compression of the files. However, there are also tools for optimizing image files losslessly. One approach is to use the .jpgoptim](https://github.com/tjko.jpgoptim) function available on ubuntu. Here is an excellent explanation of how it works. Lossless optimization As part of moving my blog to Hugo, I took the opportunity to optimize all the images in all my image folders.