[JoeAltmaier]

The difference between the data in the image, and the information? If for instance you upscaled text so large that it became blurry and unrecognizable, you lost information.

Our cortext is all about interpreting what we see. Almost before our brain proper has the data, nerves have begun extracting information (edges etc). Probably because it was the difference between hitting and missing the animal with the spear. Or seeing or missing the tiger in the grass.

[simias]

Precisely! I also find it interesting how, from an information theory standpoint, audio processing and image processing are effectively the same thing (audio resampling is fundamentally 1D image scaling for instance) but because humans process sounds very differently from images we end up doing things pretty differently.

For instance when we want to subjectively make images more attractive we tend increase contrast and sharpness, whereas for sound we tend to compress it, effectively reducing "audio contrast".

[strogonoff]

The old habit of reaching to “increase contrast”[0] as a means of making an image more attractive exists in large part because 1) the dynamic range of modern display media is so tiny compared to the dynamic range of camera sensors and our eyes[1], and 2) the images most people typically work with are often recorded in that same tiny dynamic range.

If you work with raw photography, you will find that, as with audio, the dynamic range is substantially wider than the comfortable range of the available media: your job is, in fact, to compress that range into the tiny display space while strategically attenuating and accentuating various components—just like with raw audio, much more goes into it than merely compression, but fundamentally the approaches are much alike.

[0] Which actually does much more than that—the process is far from simply making the high values higher and low values lower.

[1] Though “dynamic range” is much less of a useful concept when applied to eyes—as with sound, we perceive light in temporal context.