- Delta Encoding – The compressor stores the difference in neighboring pixels, especially useful for large areas that are similar like a picture of the sky or water. Can be extended to group blocks of nearby pixels.
2. Images often have metadata attached like geolocation and as a display resource that is a waste of space and slows load times.
3. CSS pixels can contain 1 to many physical pixels. They are not the same but the more physical pixels the better it looks.