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:
Apr. 08, 1997
Filed:
Nov. 30, 1995
Terrence M Shannon, Kuna, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A source image is scaled to a destination image using a method which determines a first destination pixel position corresponding to a given source image pixel. The method comprises the steps of: compiling a scale table having one entry per source pixel in a 'pixel group', the end destination pixel of a pixel group positioned where a first accumulation (i.e., 'Scale Source Sum') of sets of m pixels, equals a second accumulation (i.e., 'Scale Destination Sum') of sets n pixels, the Scale Source Sum derived by successively adding an m pixel set value for each successively read source pixel, and the Scale Destination Sum derived by successively adding an n pixel set value for each written destination pixel; factoring both an n source pixel set value and an m destination pixel set value by y, where y is a largest common denominator of both n and m, to derive 'n (factored source)' and 'm (factored destination)'; using the n(factored source) to determine an integer number of pixel groups between the first source image pixel and the initial source pixel, and determining a total number of destination pixels encompassed by the integer number of pixel groups; determining a position of the given source image pixel within a pixel group on the source raster image scan line; using the scale table to determine a corresponding destination pixel within the pixel group; finding the first destination pixel and positioning the scaled version of the source image thereat.