obscure features of jpeg
Tags: computers, articles
Progessive JPEGs
- contains data in a different order, lets the decoder produce a full-sized image from first chunk of file with low detail, then fill details in as image loads
- originally made for web browsers over slow connections
Multi-Scan JPEGs
- Regular JPEGs are single scan sequential: all data is stored from top to bottom, with colors and coefficients in full
- Multi-scan stores this in a separate way, allows JPEGs to be scanned multiple times, each scan loading additional data
- Means that first load can show sketch of image, second load can show colors, etc
