Apple Inc.
Backwards-Compatible High Dynamic Range (HDR) Images

Abstract:

Devices, methods, and program storage devices for creating and/or displaying backwards-compatible High Dynamic Range (HDR) images are disclosed, comprising: obtaining two or more exposures of a scene; creating a gain map based on at least one of the two or more exposures, wherein the gain map comprises a plurality of pixels each corresponding to a portion of the scene, and wherein values of the pixels in the gain map comprise indications of a brightness level of the corresponding portions of the scene; combining the two or more exposures to form a first image; tone mapping the first image based on a Standard Dynamic Range (SDR) format to generate a first SDR image of the scene; and storing the first SDR image and created gain map in a first enhanced image file. The first enhanced image file may be, e.g., a HEIF, HEIC, PNG, GIF, JPEG, or other suitable file format.