ISO 21496-1: Universal standard for HDR photography on Android and iOS

High dynamic range (HDR) has been a significant breakthrough in photography, especially with HDR support on Android devices and the introduction of Google’s Ultra HDR format. However, there has long been a problem with incompatibility of HDR photos between platforms, especially between Android and iOS. Now that problem is solved: as Android Authority reports, Google and Apple have adopted a single standard for HDR metadata, ensuring that images display correctly on any platform.

Ultra HDR: a new JPEG-based approach

Google’s Ultra HDR format is radically different from previous methods of creating HDR, which used overlaying multiple photos. Instead, Ultra HDR saves a photo as a single JPEG file with metadata containing a “gain map” – a map of brightness and color gain. On HDR-enabled devices, this allows for a realistic effect, but if HDR is not available, the photo is displayed in standard dynamic range (SDR).

Solving problems for app developers

The key difficulty was the differences in metadata encoding. Google used Adobe’s standard, while Apple used its own method, making it difficult to display HDR on different platforms. To unify, developers turned to the new ISO 21496-1 standard, which allows HDR photos to be uniformly encoded with a gain map and makes images fully cross-platform.

Expanding support for the standard

At the recent WWDC conference, Apple announced an API for handling gain map in iOS 18 and macOS 15, and its core apps like Messages and Photos have already adapted to the new standard. MacBook users are already seeing HDR images rendered correctly on Google Pixel.

Google has also integrated ISO 21496-1 into Android 15, adding dual encoding for Ultra HDR compatibility with iOS and other platforms. Google Chrome and the Google Photos app now support the new standard, making it possible to view HDR photos on Android and iOS.

The new standard is now supported by Google Chrome and the Google Photos app.

ISO 21496-1 makes it easier to capture and share HDR photos, making high-quality images available on any device. The adoption of this standard by both companies not only improves interoperability, but also promises convenience for users of both platforms.

Addition of this standard by both companies not only improves interoperability, but also promises convenience for users of both platforms.