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. 25, 1989
Filed:
Aug. 14, 1987
Hermann Fuchsberger, Ismaning, DE;
Eduard Wagensonner, Aschheim, DE;
AGFA-Gevaert Aktiengesellschaft, Leverkusen, DE;
Abstract
The invention relates to a method and apparatus for electronic contrast valuation of two-dimensional transparent original images, in which the original images are electro-optically scanned by rows and columns. The image signals, corresponding to the image elements or pixels, and possibly needing correction, are subjected to frequency filtering, in which they are modified by a low-pass filter. The resulting low-pass signals are summed with corresponding high-pass signals obtained by subtraction of low-pass signals from the original image signals. The amplification factor for the high-pass signal is determined according to a non-linear transfer characteristic function K2, such that small signals corresponding to low image contrast are more greatly amplified (amplification S.sub.1) than are large signals corresponding to high image contrast (amplification S.sub.2), and that the low-pass signals are modified according to a non-linear gradation characteristic function K1 prior to the addition of the high-pass and low-pass signals.