Google explains how the Live HDR+ function at the Pixel 4 and 4a works

Peter 04 August 2020Google Android

The new Pixel 4a helps Live HDR+ and Dual Exposure, capabilities first delivered with the Pixel 4 (word that these received’t be backported to older gadgets). The tech massive published a detailed blog publish explaining how the two functions paintings.

Google explains how the Live HDR+ characteristic at the Pixel 4 and 4a works

First, what is Live HDR+? It shows a real time preview of what the very last HDR+ photograph will look like. Note that that is only a preview derived the usage of a distinctive algorithm. The real HDR+ takes three-15 underexposed snap shots (to reduce noise), aligns them and merges them.

After the merge, tone mapping is implemented to produce the final picture wherein details in each highlights and shadows are visible. The telephone computes a 2D histogram to attain that, that is interesting to see.

Google explains how the Live HDR+ function at the Pixel four and 4a works

However, modern cellular chipsets don’t have the computational energy to do this 30 instances in line with 2nd. Instead, a sprint of AI is used. The photo is sliced into small tiles and the AI predicts the tone mapping for each of them. Then each pixel on the viewfinder is computed as a combination of the tone maps from the nearest tiles.

Here’s a evaluation between the anticipated photograph and the real HDR+ end result. It doesn't get it quite right, however it appears pretty close (in particular when you consider that you may be viewing this on the smartphone's display screen).

Predicted HDR image (visible on the viewfinder) vs. Actual HDR+ result

Predicted HDR photograph (visible at the viewfinder) vs. Real HDR+ end result

Balancing highlights and shadows is done robotically via HDR+. The Dual Exposure sliders give you manual manage over the manner, so you can get the favored look for your photo in digital camera. Traditionally, that is something you'll do afterwards by processing the RAW document.

Same scene, one-of-a-kind changes to the Dual Exposure sliders

Same scene, one of a kind modifications to the Dual Exposure sliders

If you want a extra specific rationalization of ways all of this works, you can follow the Source hyperlink to Google's blog post for extra.