Method for rendering visible security information of a digitally stored image, and image reproduction device for carrying out such a method

Abstract

A method for rendering visible security information of a digitally stored image which has a plurality of pixels and at least one piece of digitally coded information comprises at least the following steps: allocating at least some of the pixels to at least one image region; determining an average color value of the pixels allocated to the image region; determining two mutually complementary color values whose average color value is at least approximately identical to the determined average color value of the pixels allocated to the image region; depicting the image region and at least part of the digitally coded security information in a visually perceptible manner. The depicted image region thereby has a first of the mutually complementary color values. The part of the digitally coded security information is depicted within the image region and has a second of the mutually complementary color values.

Dependencies are inferred from the claim text.