Following are the JPEG operation modes:

- Lossless Mode: Every pixel in the image is encoded even though the compression ratio is low.

- Sequential Mode: A single scan from left-to-right and top-to-bottom compresses the image.

- Progressive Mode: Multiple scans are used to compress the image. The transmission time is long.

- Hierarchical Mode: Multiple resolutions are used to compress the image. Hence the lower resolution is accessed first which does not require the decompressing the whole resolution of the image.