Comparison of CCITT Group 4 compression with wrap-around and standard CCITT Group 4 compression

Technical Report · Mon Feb 29 04:00:00 EST 1988

OSTI ID:6929955

This report documents the results of a test conducted to investigate and compare the difference in performance between two different compression algorthms. For the test, aperture cards containing a series of A through E size engineering drawings were captured first utilizing CCITT Group 4 compression with ''wrap around'' and subsequently utilizing ''standard'' CCITT Group 4 compression. Samples consisting of 20 Army aperture cards and 20 Air Force aperture cards were used for the test. Each aperture card sample contained four A,B,C,D, and E size drawings. The forty(40) aperture cards were scanned, and the images were first compressed with the ''wrap around'' algorithm used in the DSREDS/EDCARS systems. The compressed image file sizes were recorded, and the compression ratios were calculated. The image files were subsequently decompressed and input into a PC-resident KoFax board that compressed the image files utilizing the standard CCITT Group 4 compression algorithm modified for larger drawings. Compressed image file sizes were recorded, and the compression ratios were calculated. Results of the test are summarized and presented in this report.

• Research Organization: Lawrence Livermore National Lab., CA (USA); Alpharel, Inc., Camarillo, CA (USA); West Coast Information System, Walnut Creek, CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6929955
• Report Number(s): UCRL-15934; AITI-87-001; ON: DE88012235
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990220* -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
990300 -- Information Handling
ALGORITHMS
COMPARATIVE EVALUATIONS
DATA
DATA PROCESSING
DIAGRAMS
ENGINEERING DRAWINGS
INFORMATION
INFORMATION RETRIEVAL
MATHEMATICAL LOGIC
NUMERICAL DATA
PROCESSING
PUNCHED CARDS
STATISTICAL DATA
TESTING