Google’s Portrait Light feature can improve the look of some of your poorer photos by giving you a way to change their direction and light intensity. The tech giant launched the AI-based lighting feature in September for the Pixel 4a 5G and Pixel 5 before giving away older Pixel phones access to him. Now Google has published an article on his AI blog explaining the technology behind Portrait Light, including how he trained his machine learning models.
In order to train one of these models to add lighting to a photo in a certain direction, Google needed millions of portraits with and without additional lighting coming from different directions. The company used a spherical lighting setup with 64 cameras and 331 individually programmable LED light sources to capture the photos it needed. He photographed 70 people with different skin tones, face shapes, genders, hairstyles and even clothing and accessories, lighting them up inside the sphere one light at a time. The company also trained a model to determine the best lighting profile for automatic light placement. His article has all the technical details, if you want to know how the feature came about.