ArcSDE - Northeast Arc Users Group

Compressions DescribedLoss-lessLossyType: • LZ77 • JPEG (quality 5 – 95)• JPEG 2000 (quality 1- 255)Applies to:Amount ofcompression:Best for:• All data types• Moderate (2:1, 3:1)• Higher for morehomogenous data• Further data processing• Data with sharp edges• JPEG – 8 bit unsigned• JP2 – 8 + 16 bit unsigned• High (5:1, 15:1)• User controlscompression / quality ratio• Data only used as backdrop• Smooth, continuous imagesExamples:• Analytical surfaces/DEMs• Analytical satellite /aerial images• Scanned linework andcolormapped images• Digital photos• Imagery for base-mapping/cartographic output• Scanned true-color maps