Following the release of the second developer preview of Android 8.1 Oreo, owners of the Pixel 2 and Pixel 2 XL can finally enable the Pixel Visual Core, a custom system-on-chip Google developed in collaboration with Intel and integrated into its last two flagships. To do so, make sure your device is actually running the latest experimental build of the operating system which you should have already received in the form of an over-the-air (OTA) download if you're participating in the Android beta. Those that aren't can always enroll in the program by referring to the banner below as Google didn't place a limit on the number of participants.
Once you're running Android 8.1 Oreo Developer Preview 2, launch the Settings app, tap "System," and go to the "About phone" section on the following interface. From there, you'll have to enable developer options by quickly tapping the "Build number" item five times. Doing so will present you with the regular lock screen where you'll need to authenticate, after which a new "Developer options" item will appear in the main Settings menu. Tap it, navigate to the "Debugging" section and turn on the toggle saying "Camera HAL HDR+." Once the toggle is enabled, reboot your device and that's it - your Pixel 2 or Pixel 2 XL now have the Pixel Visual Core running in the background.
The silicon itself is meant to help third-party apps process HDR+ photography, so enabling it won't change the quality of images delivered by the default Camera app which has already been highly optimized by Google. Developers seeking to take advantage of the chip will have to make their apps use the Android Camera API but many popular services like Instagram, Facebook, and Manual Camera already do so. In practice, the chip isn't likely to significantly improve the quality of your shots but what it will enhance is the actual image processing, meaning you can expect third-party apps using the Android Camera API to take photos more quickly and while using less battery. With machine learning being an essential component of the Pixel Visual Core, this hardware could also become much more efficient with use going forward and since power efficiency is the name of the game here, enabling the chip on your device shouldn't negatively affect its battery life and is instead likely to have an opposite effect.