Nvidia Corporation

Yanbo Sun

Tyvis Cheung

Gennady Petrov

Gerrit Ary Slavenburg

Lauri Hyvarinen

Weiwan Liu

Dong Han Ryu

Certain display types—such as organic light emitting diode (OLED) displays—may be more prone to burn-in or ghosting due to the varied luminance degradation rates of pixel cells of the display—especially in applications or content types that require display of prolonged, continuous, static textures. To account for this, aging of pixel cells (e.g., R, G, B, and/or W pixel cells) of a display may be tracked such that more aged pixel cells may be compensated for by reducing pixel values of one or more (e.g., each) other pixel cells of the display. As a result, the effect of burn-in or ghosting may be mitigated by tracking luminance degradation over time and compensating for the luminance degradation across some or all of the pixel cells of the display.

Pixel degradation tracking and compensation for display technologies

The disclosure is directed to transforming signals from one signal format to another signal format. For example, the format of a digital signal can change from storing video information in 12 bits of data to storing the video information in 32 bits of data. Other storage values and combinations can also be used. Since the number of bits available to store a portion of the video information can change when changing formats, a process is needed to translate or transform the video information appropriately. A transfer function utilizing a lookup table is used for the transforming. The lookup table utilizes a variable step size segmentation scheme that decreases the amount of lookup table storage space required and also decreases the number of estimation errors, i.e., interpolation errors. Estimation errors can occur when looking up a value not stored in the lookup table, and using neighboring values that are stored to estimate the value requested. In some applications, the logstep size or total size values can be stored in the lookup table to further reduce the amount of storage space required. A video parameter, such as the type of video content and the display room ambiance, can also be used to select the balance between further decreasing the size of the lookup table and further decreasing the estimation errors.

Transfer of video signals using variable segmented lookup tables

The present disclosure is directed to a process to partially or fully suppress, or limit, pixel coloration errors. These pixel coloration errors, represented by small noise values, can be introduced during signal processing of high dynamic range (HDR) video signals. Converting visual content to a half precision floating point representation, for example, FP16, can introduce small amounts of signal noise due to value rounding. The noise can be multiplied and accumulated during HDR signal processing resulting in visual artifacts and degraded image quality. The disclosure can detect these noise amounts in pixel color component values, and suppress, or partially suppress, the noise to prevent the noise from accumulating during subsequent HDR signal processing.

Growing community of inventors

Santa Clara, CA, United States of America

Yanbo Sun