Compression Algorithm of Road Traffic Spatial Data Based on LZW
Method RCSCoR RCSJoR 1bSCoR LZW
JPEG MPEG-1 Ratio 4.544 8.533 15.794 1.184 3.103 1.871
Intervention Effects of ZJW and LZW
on the Corresponding SH and SC.
Furthermore, compressed images with their background removed can be subjected to additional lossless compression methods such as RLE, HE and LZW
compression algorithm used in the GIF format is owned by Unisys, and is licensed to OriginLab.
A similar result, restricted to the LZW
format, was independently found and presented in Kida et al.
In these formulas, the original scanned pixel values are transformed into other values, most often using either run-length encoding (i.e., Sunraster, TARGA, and TIFF format types 2 and 32773), LZW
encoding (i.e., GIF LZW
and TIFF scheme 5), or discrete cosine transforms, also known as DCT (i.e., JPEG DCT and MPEG DCT).
graphics technology, that GIF is based on, is a legacy from the 1980s that Unisys inherited.
A compression format developed by CompuServe using Unisys's patented LZW
(Lempel-Ziv-Welch) technique, GIF files are bitmaps composed of individual pixels.
Angela Finet, Millstar's project leader for EEM 1997, said, "We had to find a new compression technology since Unisys began enforcing their patent on TIFF LZW
compression, which is what we used last year.