Methods and apparatus for hybrid halftoning of an image

Abstract

This disclosure provides methods, apparatus, and computer programs encoded on computer storage media for tone based halftoning of digital images. By exploiting knowledge of local image features and tone levels, the halftoning method may be adaptively switched between error-diffusion and mask-based dithering with reduced boundary artifacts. By further utilizing a smart quantization error clipping scheme, artifacts inherent to the method of error diffusion are also reduced. The method consistently generates higher quality halftone images for both still and video applications when compared to conventional methods.

Description

technical field [0001] The present disclosure relates to halftoning methods and apparatus for electronic displays, such as displays including interferometric modulators. Background technique [0002] Electromechanical systems (EMS) include devices having electrical and mechanical elements, actuators, transducers, sensors, optical components (eg, mirrors), and electronics. Electromechanical systems can be fabricated in a variety of dimensions, including but not limited to microscale and nanoscale. For example, microelectromechanical systems (MEMS) devices may include structures having sizes ranging from about one micron to hundreds of microns or more. Nanoelectromechanical systems (NEMS) devices can include structures having sizes smaller than a micron, including sizes smaller than hundreds of nanometers, for example. Electromechanical elements may be formed using deposition, etching, photolithography, and / or other micromachining processes that etch away portions of substra...

AI Technical Summary

Problems solved by technology

In general, however, halftone images produced by mask-based dithering have the lowest image quality due to: pattern visibility, noisy appearance (especially in midtone areas), inability to reproduce detail and the resulting limited number of gray levels

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