There are at least two problems with this article in how its argument is constructed.<p>First, it’s a response to two other articles and does not refer to the images in those articles or the processing techniques used on them, instead grabbing four other images and transforming them, perhaps in the same way as the original article, perhaps not. From this it draws broad conclusions. As the joke goes, at least one side of the sheep appears black from here.<p>The second is that there is a source of truth for these claims, and it’s in the algorithms and file formats in question. A JPEG image is generated and compressed a certain way, a PNG is encoded in a certain way. There is an actual answer to the question of whether or not dithering saves space and under what circumstances, and it has to do with how the images are encoded and compressed. If one does not want to bother learning enough about the algorithms in question, at the least one could approximate that knowledge by processing a statistically significant number of images and evaluating the results to get some kind of actual data on when and where the technique generates larger or smaller file sizes.<p>Instead, we’ve now got three articles, two of which say “this works” and one of which says “no it doesn’t” with all the rigor of 18th century naturalists puzzling over the behavior of birds.