Tonescale compression for electroluminescent display

A method for controlling an electroluminescent display to produce an image for display that has reduced luminance to reduce burn-in on the display while maintaining visible contrast, the method comprising:

• providing the electroluminescent (EL) display comprising a plurality of EL emitters, the luminance of the light produced by each EL emitter being responsive to a respective drive signal;
• receiving a plurality of input image signals for each EL emitter, the input image signals having a peak frame luminance, each input image signal corresponding to a respective one of a plurality of frames;
• transforming the input image signals to a plurality of drive signals comprising a reduced peak frame luminance value while maintaining contrast in the displayed image to reduce burn-in by adjusting the drive signals to have reduced luminance provided by each pixel, the transforming comprising:
• determining the peak frame luminance based on the time when a static image is displayed;
• holding the peak frame luminance constant for i frames after the static image is displayed;
• reducing the peak frame luminance by a first exponential function until a time Fs;
• once Fs is achieved, peak frame luminance is reduced by a second exponential function;
• and
• wherein the drive signals are further adjusted so that a luminance decrease in a shadow range is less than a luminance decrease in a non-shadow range in the displayed image for the drive signals with reduced peak frame luminance.