Apple Inc.

Other

Instrument Systems Optische Messtechnik Gmbh

Instrument Systems Gmbh

Marcu, Gabriel G.

Hayward, David

Zimmer, Mark

Gabriel G Marcu

Wei Chen

Steve Swen

Kok S Chen

Jiaying Wu

Cheng Kai Chen

Jun Qi

Ian C Hendry

Lu Zhang

Marc Albrecht

John Z Zhong

Mark Zimmer

Sandro Hermann Pintz

David Hayward

Kenneth I Greenebaum

Ye Yin

Victor H Yin

Ming Xu

Chaohao Wang

Ricardo Jansson Motta

Mingxia Gu

David W Lum

Ulrich Tobias Barnhoefer

Jesse Michael Devine

Shahram Peyvandi

Anuj Bhatnagar

Luke Stanislaw Wallis

Hopil Bae

Keith Alan Cox

Francisco H Imai

Peter N Graffagnino

Rong Liu

Yi Huang

Jean-Jacques P Drolet

Arkady Ten

Kelsey Yukio Ho

Bongsun Lee

Chenhua You

Yanming Li

Po-Chieh Hung

Xiran Wang

Hongqin Zhang

Robert K Molholm

Jean-François Mulé

Andrew P Aitken

Chia-Ching Chu

William Mathews Riedel

Jose Olav Andrade

Julia C Davoud

Abhijit Bhattacharya

Christopher William Baldwin

Benjamin John Becher

John Z Z Zhong

Cheng Chen

A display panel is calibrated to a target white point. A maximum luminance value of the display panel is attenuated from a first luminance value associated with the target white point to a second luminance value based on an attenuation factor. The second luminance value is equal to or lower than the first luminance value. The display panel is re-calibrated based on a chromaticity of the target white point and the second luminance value to generate calibration data. The calibration data is flashed into memory associated with the display panel. During operation, the white point of the panel may be shifted from the target to a chromatically imbalanced (e.g., reddish) white point that may cause motion-induced color trail or color breakup artifacts. The attenuated second luminance value ensures the motion-induced color trail or color breakup artifacts are adequately masked when the panel is driven with the chromatically imbalanced white point.

Method and apparatus for color calibration for reduced motion-induced color breakup

An output device is set to a first state in which a value of a first characteristic of the output device is set to a first value. Pixel adjustment values for plural gray levels are set to first pixel adjustment values in response to the output device being set to the first state. The value of the first characteristic is changed from the first value to a second value to set the output device to a second state. The pixel adjustment values for the plural gray levels are updated to second pixel adjustment values in response to the output device being set to the second state. The second pixel adjustment values are derived based on the second value of the first characteristic. Pixel values applied to a plurality of pixels of the output device are corrected based on the second pixel adjustment values.

Gray tracking across dynamically changing display characteristics

A display calibration system may include a first electronic device that includes an ambient light sensor and a display to be calibrated in a second electronic device. The first electronic device may generate test patterns to be displayed on the display. The ambient light sensor may receive light emitted from the display based on the test patterns to generate display color space data. The first electronic device may generate calibration data for the display based on the display color space data and a target reference color space. The second electronic device may store the calibration data and use the calibration data to generate more accurate images. Because the first electronic device may include other functionalities other display calibration, specialized display calibration equipment may be omitted. Additionally, a third electronic device that acts as an intermediary between the first and second electronic devices.

Display calibration system

A display panel is initialized to a native state where no color corrections are applied. A native response of the display panel is measured in the native state. One or more calibration operations for the display panel are performed based on the measured native response and calibration data is generated. The generated calibration data is stored in a timing controller (TCON) chip of the display panel. One or more chromaticity values of the display panel are measured while driving the display panel in a calibrated state based on the generated calibration data. The measured chromaticity value of the display panel is stored as Extended Display Identification Data (EDID) or DisplayID data in the TCON.

Optimum chromaticity calibration

First color response values of vertices of a first unit cube defined within a cubic color output space of the display device are measured. For each of first intermediate values determined based on the measured first color response values, RGB adjustment values are calculated by tetrahedral decomposition and interpolation so that each calculated RGB adjustment value is within a boundary defined by the first unit cube. When boundary defined by the first unit cube is reached, a second unit cube is defined within the cubic color output space, wherein a first vertex of a plurality of vertices of the second unit cube corresponds to the calculated RGB adjustment values of a previous intermediate value that is one of the first intermediate values. Second color response values corresponding to the plurality of vertices of the second unit cube except the first vertex are measured.

Method and system for display color calibration

Pixel values of image content are lowered in response to setting a display mode so that the lowered pixel values of the first image content are mapped to a first color gamut. The first color gamut is defined by a nominal range space and is lower than a native color gamut of a display panel. The native color gamut is defined by the nominal range space and an extended range space that is outside of the first color gamut. One or more parameters are obtained for the image content in the display mode. A color boosting operation is performed for, from among the lowered pixel values of the image content in the nominal range space, each of first pixel values that meet one of the parameters. A color associated with each of the first pixel values is proportionally enhanced without changing a corresponding hue to utilize the extended range space.

Color rendering for images in extended dynamic range mode

Scalable color balancing techniques for processing images to be presented on displays are described. One technique includes receiving ambient light color information from an ambient light sensor and input image data to be presented via a display coincident with receiving the ambient light color information. The display may have a first white point at a time prior to receiving the input image data. The technique may include determining a second white point for the display based on the input image data and the ambient light color information. The first and second white points may differ from each other. The technique may also include generating one or more chromatic adaptation transforms (CATs) based on the white points. Output image data may be generated based on applying the one or more CATs to the input image data. The output image data may be presented via the display. Other embodiments are described.

Scalable chromatic adaptation

A method and user interface for direct setting of black and white points. Black point is set using a slider and matching of gray shades. White point setting is performed by having a setting object move within a defined region, such as a square or circle, with the area where the setting object moves being adjusted dynamically based on the location of the setting object with respect to the defined region. When the area is the desired white, the setting is complete. Preferably the defined region has a varying color border to allow a reference for the user in moving the setting object. A more detailed setting of gray levels can be accomplished by providing a gray scale with reference points. Each reference point has an associated white point setting area, so that settings are developed for each reference point. Settings at other locations are determined by interpolation or extrapolation.

User interface and method for directly setting display white point

A display may store extended display identification data for communicating the capabilities of the display to a source device such as a graphics processing unit. The extended display identification data may include a red primary color value, a green primary color value, and a blue primary color value. The primary color values in the extended display identification data may be determined during manufacturing. For example, a light sensor may measure the native primary colors of the display, and calibration computing equipment may determine if the native primary colors of the display are within a target color gamut. If the native primary colors of the display are outside of the target color gamut by an amount larger than a threshold, the primary color values in the extended display identification data may be adjusted to account for the color variation.

Displays with unit-specific display identification data

An electronic device may include a display having an array of display pixels and having display control circuitry that controls the operation of the display. The display control circuitry may adaptively adjust the display output based on ambient lighting conditions. For example, in cooler ambient lighting conditions such as those dominated by daylight, the display may display neutral colors using a relatively cool white. When the display is operated in warmer ambient lighting conditions such as those dominated by indoor light sources, the display may display neutral colors using a relatively warm white. Adapting to the ambient lighting conditions may ensure that the user does not perceive color shifts on the display as the user's vision chromatically adapts to different ambient lighting conditions. Adaptively adjusting images in this way can also have beneficial effects on the human circadian rhythm by displaying warmer colors in the evening.

Ambient light adaptive displays

An electronic device may have a display such as a liquid crystal display. The display may have an array of pixels that display images to a user. Backlight structures may provide the array of pixels with backlight illumination at a backlight illumination level. The backlight structures may have a light source with an array of light-emitting diodes and photoluminescent material that is pumped by pump light from the light-emitting diodes. The backlight illumination may experience color variations as a function of the backlight illumination level. Circuitry in the electronic device may be used to implement a backlight level color compensator. The backlight level color compensator may apply color correction factors to the image data of the displayed images to compensate for variations in color of the image data due to variations in backlight illumination level and operating temperature.

Display with backlight and temperature color compensation

An electronic device may include a display having an array of display pixels. Each display pixel may include a red subpixel, a green subpixel, a blue subpixel, and a white subpixel. The display may be controlled using display control circuitry. The display control circuitry may convert frames of display data from a red-green-blue (RGB) color space to a red-green-blue-white (RGBW) color space. The display control circuitry may supply data signals corresponding to a frame of display data in the RGBW color space to the array of display pixels. A frame of display data may be converted from the RGB color space to the RGBW color space based on an amount of color saturation in the frame of display data, based on information identifying what code is running on control circuitry in the electronic device, and/or based on ambient lighting condition information.

Adaptive RGB-to-RGBW conversion for RGBW display systems

A display may have a first stage such as a color liquid crystal display stage and a second stage such as a monochromatic liquid crystal display stage that are coupled in tandem so that light from a backlight passes through both stages. The dynamic range of the display may be enhanced by using the second stage to perform local dimming operations. The pixel pitch of the second stage may be greater than the pixel pitch of the first stage to ease alignment tolerances and reduce image processing complexity. The color stage and monochromatic stages may share a polarizer. A color filter in the color stage may have an array of red, green, and blue elements or an array of white, red, green, and blue elements. The color stage may be a fringe field display and the monochrome stage may be an in-plane switching display or a twisted nematic stage.

High dynamic range liquid crystal display

An electronic device may include a display having an array of display pixels. Storage and processing circuitry may generate display data for the display in an RGB input color space. The display may display the display data in an RGBW output color space. Display control circuitry may use sets of predetermined conversion factors to convert display data from the RGB input color space to the RGBW output color space without requiring conversion to a device-independent color space. Each set of predetermined conversion factors may be associated with a color in a set of predetermined colors. Using the sets of predetermined conversion factors, the display control circuitry may convert RGB values in the input color space to RGBW values in the output color space. The display control circuitry may supply data signals corresponding to the display data in the RGBW output color space to the array of display pixels.

Color space conversion methods for electronic device displays

Growing community of inventors

Sunnyvale, CA, United States of America

Gabriel G Marcu