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:
Dec. 06, 1994
Filed:
Sep. 28, 1989
Stuart C Wells, Santa Clara, CA (US);
Grant J Williamson, Sunnyvale, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
The method and apparatus of the present invention takes into consideration that the eye is more sensitive to intensity variations at low levels of intensity than at high levels of intensity and produces higher quality dithered images by employing a sectioned or piecewise linear quantization strategy which sacrifices the fineness of interval spacing at the high end of the intensity scale in order to achieve greater accuracy of reproduction at the low end. The input intensity values are divided into a plurality of sub-ranges indicative of low intensities and high intensities. The number of input intensity levels allocated to the low intensity sub-ranges is small and the number of quantized or output intensity levels allocated to the low intensity sub-ranges is large compared to those allocated to the high intensity sub-ranges such that the interval spacing at the low intensity sub-ranges is small to provide greater accuracy at the low intensity levels where the eye is most sensitive.