Methods and systems for adjusting contrast in devices

A method for displaying information on a display device, the method comprising:

• obtaining information about ambient light in an environment surrounding the display device;
• for a set of pixels on the display device that are used to display the information, obtaining information about target luminance values and background luminance values for each of the pixels;
• obtaining information about a contrast threshold value for a viewer of the display device;
• determining a Weber contrast value for each one of the set of pixels;
• determining a range of target luminance values for a subset of the pixels for which the Weber contrast value is less than the contrast threshold value;
• adjusting luminance values for the set of pixels so that at least some members of the subset of pixels have Weber contrast values, based on their adjusted luminance values, that exceed the contrast threshold value;
• and
• displaying the visual information on the display device using the members of the set of pixels with the adjusted luminance values.

A imaging device, comprising:

• an image sensor configured to obtain an image;
• and
• an electronic processor connected to the image sensor,
• wherein during operation of the device, for a set of pixels corresponding to a first image obtained by the image sensor, the electronic processor is configured to:
• obtain information about ambient light in an environment of the device;
• obtain information about target luminance values and background luminance values for the set of pixels;
• obtain a contrast threshold value;
• determine a Weber contrast value for each one of the set of pixels;
• determine a range of target luminance values for a subset of the pixels for which the Weber contrast value is less than the contrast threshold value;
• adjust luminance values for the set of pixels so that at least some members of the subset of pixels have Weber contrast values, based on their adjusted luminance values, that exceed the contrast threshold value;
• and
• generate a second image based on the set of pixels and comprising the adjusted luminance values.