Patent ID: 8311328

Claim:
An electronic visual aid to a user for reading text on a background by providing optimized contrast between the text and the background, the visual aid comprising: a video camera for generating a recording of the text on the background an computer, which is supplied with the recording of the text on the background, wherein the computer provides a brightness distribution profile of the recording, the brightness distribution profile having a single step shape comprising a first zone of low brightness and low frequency corresponding to the text, a second zone of great brightness and high frequency corresponding to the background, and a transition zone between the first zone and the second zone, the evaluating unit derives from said brightness distribution a brightness threshold value lying in the transition zone; an image generator which generates from the recording a binary image having only a first and a second predetermined brightness value, the image generator assigning to the pixels of the binary image the first predetermined brightness value when the brightness of a pixel of the recording is below the brightness threshold value, and assigning the second brightness value when a pixel of the recording is above the brightness value, thereby creating a high contrast binary image of the text on the background; and a display unit is provided as a head-mounted display device that presents the high contrast binary image of the text on the background such that the high contrast binary image is viewable by the user wearing the head mounted display device.