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:
Aug. 06, 1996
Filed:
Jul. 12, 1993
Raphael L Levien, McDowell, VA (US);
Other;
Abstract
A method and apparatus for automatically correcting the tone values of a digitally stored image includes compiling a histogram of the relative occurrence of gray values in the stored image in memory. The histogram is processed by adding a constant, taking the square root, and digital filtering. The processed histogram is numerically integrated and then normalized to form a tone correction function. The present tone correction method may be used to tone correct color images by applying separate tone correction functions generated for each of the three color planes independently, or in the alternative, by applying a composite tone correction function corresponding to the average of histograms of the respective individual color planes. A switch is provided to allow the operator to view the results of both methods of automatic tone correction for color images, and choose the best resulting image.