Sorry I could have been more specific. By more optimized jpeg I meant better perceptual quality (again subjective) within the confines of what a jpeg decoder co

Sorry I could have been more specific. By more optimized jpeg I meant better perceptual quality (again subjective) within the confines of what a jpeg decoder could understand. To co opt your knobs analogy I imagine each of the steps of a complex image compression pipeline comes with its own knobs each with its own tradeoffs. The dream here would be to tune all those knobs at the same time to optimize some sense of quality in a particular image. Of course huge disclaimer I’m not an image or signal processing expert. It’s also very possible that these “knobs” have been tuned well enough so that even if we optimized them for a specific image the quality difference would not be noticeable.