Browse Prior Art Database

Optimal Image Resolution Reduction Method for Predictive Compression Algorithms

IP.com Disclosure Number: IPCOM000049681D
Original Publication Date: 1982-Jul-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Abraham, DG: AUTHOR

Abstract

A voting technique for reducing the resolution of image data converts a group of high resolution picture elements into a single, low resolution picture element by determining whether the high resolution picture element group has a majority of white or black picture elements. Where the high resolution picture element group has an equal number of black and white picture elements, the decision on what value to assign the low resolution picture element can be made by reference to a compression technique in such a way as to improve the ultimate compression efficiency of the reduced resolution image.

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Optimal Image Resolution Reduction Method for Predictive Compression Algorithms

A voting technique for reducing the resolution of image data converts a group of high resolution picture elements into a single, low resolution picture element by determining whether the high resolution picture element group has a majority of white or black picture elements. Where the high resolution picture element group has an equal number of black and white picture elements, the decision on what value to assign the low resolution picture element can be made by reference to a compression technique in such a way as to improve the ultimate compression efficiency of the reduced resolution image.

A common compression technique employs, as a preliminary step, the transformation of image data through use of a predictive algorithm into an error image which can be expected to have a higher compression efficiency, with respect to run length based compression algorithms, than an untransformed image. One common predictive transform algorithm employs three picture elements in a preceding line immediately above the picture element whose value is to be assigned, as well as the immediately preceding picture element in line with the picture element whose value is to be assigned. The combination of values in the four known picture elements are each associated with specific predictions as to the value in the picture element to be determined.

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