Browse Prior Art Database

High-Density Digital Camera Utilizing Low-Energy Consuming Compression

IP.com Disclosure Number: IPCOM000119346D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 1 page(s) / 34K

Publishing Venue

IBM

Related People

Feig, E: AUTHOR

Abstract

A digital camera is disclosed which enables one to store considerably more images by utilizing compression techniques. These techniques are performed by very low power consuming devices, thereby increasing dramatically the battery life powering the system.

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High-Density Digital Camera Utilizing Low-Energy Consuming Compression

      A digital camera is disclosed which enables one to store
considerably more images by utilizing compression techniques.  These
techniques are performed by very low power consuming devices, thereby
increasing dramatically the battery life powering the system.

      Digital cameras are now on the market.  They generally enable
the user to store very few images (about 8) on a disk.  With visually
lossless compression techniques, one can dramatically increase the
number of stored images by a factor between 10 to 20.  However,
compression devices consume quite a lot of power.

      How one can compute a two-dimensional Discrete Cosine Transform
(DCT) on 8 x 8 points using very little arithmetic was shown in [*].
A particular embodiment, which is preferred for the present
invention, calls for 54 multiplications and 454 additions, with all
arithmetic performed on 16-bit integers.

      The compression scheme suggested here is two-dimensional scaled
DCTs followed by quantization.  The quantization is via a scaling
matrix which is composed of all powers of 2.  Thus, the procedure
never calls on a division for compression, nor a multiplication for
decompression.  The compression ratios will not be optimal, but they
will be very close.

      Reference
(*)  E. Feig, "A Fast-Scaled DCT Algorithm," Proceedings of the 1990
SPIE/SPSE Symposium on Electronic Imaging Science and Techno...