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:
Sep. 12, 1989
Filed:
Sep. 22, 1988
Andrew J Yeomans, Hertfordshire, GB;
Crosfield Electronics Limited, London, GB;
Abstract
Apparatus for processing a digital representation of an image in which each pixel is defined by at least one digital color component value, the value comprising one of a first set of values defining a first scale of color component values. The apparatus comprises a store for storing digital color component values for the image pixels; and a first look-up table (LUT) addressed by a color component value from the store corresponding to a selected pixel, the first LUT generating a signal representing a modified color component value chosen from a set of modified color component values defining a second scale coarser than the first scale. Three second LUTs are provided which are addressed by the color component value from the store in parallel with the first LUT, each second LUT generating an error value signal, the sum of the error values being equal to the difference between the modified color component value and the color component value from the store as measured on the first scale. Modification stores allow corresponding color component values of pixels associated with the selected pixel to be modified in accordance with respective ones of the error value signals.