The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 1994
Filed:
Apr. 08, 1992
Peter T Barrett, Palo Alto, CA (US);
SuperMac Technology, Sunnyvale, CA (US);
Abstract
A method and apparatus for image compression suitable for personal computer applications, which compresses and stores data in two steps. An image is captured in real-time and compressed using an efficient method and stored to a hard-disk. At some later time, the data is further compressed in non-real-time using a computationally more intense algorithm that results in a higher compression ratio. The two-step approach allows the storage reduction benefits of a highly sophisticated compression algorithm to be achieved without requiring the computational resources to perform this algorithm in real-time. A compression algorithm suitable for performing the first compression step on a host processor in a personal computer is also described. The first compression step accepts 4:2:2 YCrCb data from the video digitizer. The two chrominance components are averaged and a pseudo-random number is added to all components. The resulting values are quantized and packed into a single 32-bit word representing a 2.times.2 array of pixels. The seed value for the pseudo-random number is remembered so that the pseudo-random noise can be removed before performing the second compression step.