Systems and methods for local dimming in multi-modulation displays

A projector display system, comprising:

• a light source;
• a controller, said controller receiving input image data associated with an input image and said controller outputting control signals;
• a first modulator configured to receive light from said light source and configured to receive at least some of said control signals from said controller such that said first modulator is configured to render a halftone image;
• and
• a second modulator, said second modulator configured to receive said halftone image and configured to receive at least some of said control signals from said controller such that said second modulator is configured to render a modulated image to be projected to form a desired screen image corresponding to the input image, wherein the controller is configured to:
• dilate a region of said input image to the spatial extent of a blur kernel to produce a dilated input image xd(m, n);
• determine an upper bound binary halftone image bu(m, n), based on a threshold hTLevel(m, n) of a dither pattern, where bu(m, n)=xd(m, n), if xd(m, n)>hTLevel(m, n);
• multiply the luminance levels of the input image by a predetermined contrast ratio to produce a scaled input image;
• erode a region of said scaled input image to the spatial extent of the blur kernel to produce an eroded input image xe(m, n);
• determine a lower bound binary halftone image bl(m, n), based on said threshold hTLevel(m, n), where bl(m, n)=xe(m, n), if xe(m, n)≤hTLevel(m, n);
• and
• combine the upper bound binary halftone image bu(m, n) and the lower bound binary halftone image bl(m, n) by a pointwise OR-operation to form said halftone image.