| libultrahdr is an image compression library that uses gain map technology |
| to store and distribute HDR images. Conceptually on the encoding side, the |
| library accepts SDR and HDR rendition of an image and from these a Gain Map |
| (quotient between the two renditions) is computed. The library then uses |
| backward compatible means to store the base image (SDR), gain map image and |
| some associated metadata. Legacy readers that do not support handling the |
| gain map image and/or metadata, will display the base image. Readers that |
| support the format combine the base image with the gain map and render a |
| high dynamic range image on compatible displays. |
| |
| For additional information, see android hdr-image-format |
| https://developer.android.com/guide/topics/media/platform/hdr-image-format. |
