Apple Inc.

Eric L Dacquay

Ian C Hendry

Kenneth I Greenebaum

Systems, methods, and computer readable media are described for effectively using dither techniques upon signals having a predicted quantization error that varies across the range of the signal. In some embodiments, predicted error is used to shape a precision input signal so that the newly-shaped signal yields a uniform or relatively uniform predicted quantization error. A dither is applied to the re-shaped signal, and the shaping is reversed, after which the signal may be slope limited and/or quantized, taking full and efficient advantage of the dithering technique.

System and method for improving graphics and other signal results through signal transformation and application of dithering

Methods and apparatus for rendering and displaying high dynamic range (HDR) digital image content. An HDR rendering and display system may support the rendering and display of standard dynamic range (SDR) and HDR content to both HDR-enabled and standard displays. The HDR rendering and display system renders digital image content into the HDR space and maps the rendered HDR content into the display space of HDR or standard displays using display processing techniques that may preserve at least some of the HDR content even for standard displays. The HDR rendering and display system may take into account various information including but not limited to display characteristics such as size, control inputs, current image characteristics such as image brightness, and environmental information such as viewer position and ambient lighting levels to dynamically adapt the rendering and display of the digital image content according to ambient viewing conditions at the target display.

Rendering and displaying high dynamic range content

Methods and apparatus for rendering and displaying high dynamic range (HDR) digital image content according to a perceptual model. A model of viewer perceptual range may be determined according to the perceptual model based on inputs including ambient lighting conditions, display panel characteristics (e.g., light leakage and reflected ambient light), and/or display panel settings. The system may determine, according to the model of viewer perceptual range, a brightness level that defines a lower portion and an upper portion of a display space of the display panel, and a maximum rendering value M. Digital image content may be rendered according to the maximum rendering value M to generate HDR content in a dynamic range of (0.0-M). The rendered HDR content may then be mapped into the display space of the display panel according to the brightness level.

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Sunnyvale, CA, United States of America

Eric L Dacquay