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. 14, 1999
Filed:
Oct. 11, 1996
Christopher Mills, Santa Clara, CA (US);
Divicom, Inc., Milpitas, CA (US);
Abstract
A method and apparatus for prescaling graphics data for use in a graphics overlay operating mode of a set top box processing system. RGB pixel data for a given pixel are first converted to luminance and chrominance data for that pixel. The luminance and chrominance data are then prescaled by a blending value associated with the given pixel. An interpolation operation is performed on the luminance and chrominance data as well as on the blending value for the given pixel using corresponding luminance and chrominance data and blending values for at least one other pixel in the stream. This interpolation may include operations such as horizontal filtering and may also include chroma filtering to convert the luminance and chrominance data into a 4:2:2 chrominance format compatible with MPEG-2 video. The interpolation operation produces interpolated luminance and chrominance data and an interpolated blending value for the given pixel. A video signal to be combined with the graphics data is then scaled using the interpolated blending value. The scaled video signal is combined with the interpolated luminance and chrominance data for the given pixel to provide a combined video/graphics signal suitable for display.