Abstract
In many contexts, users view mixed high and standard dynamic range content (HDR/SDR) on their devices. For example, on HDR-capable smartphones, a user may view an HDR image with SDR user interface (UI) elements overlaid on it. In such contexts, when the user captures a screenshot and stores the result in an SDR image file, tone mapping can result in degradation of the SDR elements on the image. This disclosure describes a local tone mapping approach that can be used to convert HDR-SDR mixed content to SDR, where HDR elements are tonemapped without impacting SDR elements. The approach can be implemented in graphics processing unit (GPU) shaders. Per the techniques, nearby pixels are used to inform the mapping of each pixel from an HDR representation into SDR. Maximum pixel brightness is determined, and a lower bound is applied to pixel values. Tone mapping is performed only for the pixels that have a brightness value that meets a threshold, while original pixel values are retained for other pixels. In this manner, SDR elements are preserved by selectively applying tone mapping to specific pixels of the image.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Mouri, Alec, "Local Tone Mapping of Mixed HDR and SDR Content That Preserves SDR Elements", Technical Disclosure Commons, (November 19, 2024)
https://www.tdcommons.org/dpubs_series/7574