The Lempel–Ziv (LZ) compression methods are among the most popular algorithms for lossless storage. DEFLATE is a variation on LZ optimized for decompression speed and compression ratio, but compression can be slow. DEFLATE is used in PKZIP, Gzip and PNG. LZW (Lempel–Ziv–Welch) is used in GIF images. Also noteworthy is the LZR (Lempel-Ziv–Renau) algorithm, which serves as the basis for the Zip method.[citation needed] LZ methods use a table-based compression model where table entries are substituted for repeated strings of data. For most LZ methods, this table is generated dynamically from earlier data in the input. The table itself is often Huffman encoded (e.g. SHRI, LZX). Current LZ-based coding schemes that perform well are Brotli and LZX. LZX is used in Microsoft's CAB format. COUNT 5
QSN1 What compression methods are among the most popular? ANS1 Lempel–Ziv (LZ) QSN2 What is used in PKZIP, Gzip and PNG? ANS2 DEFLATE QSN3 What serves as the basis of the Zip method? ANS3 LZR QSN4 What is a current LZ based coding scheme that does well? ANS4 Brotli QSN5 What is used in Microsoft's CAB format? ANS5 LZX