Huawei P10 Plus: welcome to computational photography

The human side of computational photography is shrinking in importance. At least, that’s how Lindsey Schutters feels after spending time with the Huawei P10 Plus.

I ENJOY OUTSOURCING THINGS. Transcription work, my commute to work and now pictures of my loved ones; all handled by powerful processors. There’s a school of thought emerging that is considering the future of the smartphone camera to be no main rear camera at all. Instead the sensor and glass will be replaced by vast cloud-based image libraries. At the Eiffel Tower? Snap a selfie and Google will blend it into an existing image snapped by one of its photographer drones, adjusting lighting for time of day and current weather conditions. Now you just click “share” and the world can appreciate your holiday.

We’re not there yet. Thankfully I still had to decide on framing and fiddle with the brightness a little to achieve the examples on these pages. But the processing, outside of focus and exposure area selection (in the Huawei instances), was done by the phone. It’s incredible to think that such

tiny image sensors and lens elements can produce quality pictures.

That’s exactly the challenge Google’s X-lab wanted to solve when developing Google Glasses, the company wanted high quality images to come from the equipped camera. The solution? Blend the best elements of multiple exposures together to create one high quality image. The Glasses project has since been shelved, but the X Cam idea lives on within the Google Pixel’s Auto HDR+ mode, delivering the highest score ever from the testers at Dxomark (89).

Huawei’s P10, by contrast, scored 87, which is near the very top. The Chinese handset achieves this through a different approach to computational photography: dual cameras. A 20 MP monochrome sensor collects light, texture and contrast data and is then blended to the colour data from the 12 MP main camera sensor (I call this the main camera because it’s the only one that is used for video). As I understand it, the colour is analysed by the pixel and overlaid according to a contrast hierarchy, meaning that each colour image is a hybrid.

What I can’t deduce is how many frames the colour camera is combining to judge to establish that hierarchy. You see, to achieve high dynamic range on a pro camera, you shoot multiple exposures of the same scene and combine them in post-production. Newer cameras have a special setting built in and typically use either three or five exposures, filling a range of under- to overexposed images. This way you get better balance on highlights as well as recover detail in shadowy areas.

Samsung’s Galaxy S5 was the first smartphone to introduce live HDR preview – as well as phase detection autofocus (PDAF) – allowing users to peek behind the scenes of on-device image processing. Essentially the camera is taking a video of the scene and splicing together frames on the fly, when you press the shutter button you’re just marking one moment in time and the camera finishes/sharpens the image using that second’s range of stills.

For the average user this is a much better proposition to capturing everyday, fast-moving life. The alternative is to painstakingly dial in precise settings and properly compose an image. The P10 Plus allows for this level of granular control with a Pro mode. I personally didn’t spend too much time with this feature because my subjects are generally of the furry and/or energetic kind.

On selfie duty is the now Leica-branded 8 MP camera which has some neat new portrait gimmicks to make you look more like a porcelain doll.

In all the Huawei P10 Plus is an incremental upgrade over the powerful, task orientated Mate 9 with which it shares key specifications. The Plus variant does debut a 1440p (QHD) screen resolution and the Summilux-h Leica lenses, which seem like a slight bump in overall lens quality and a wider f/1.8 aperture over the f/2.2 openings of the Summarit system found on the standard P10 and Mate 9. Wider lenses mean more light data for the processors to play with, theoretically improving the data science (more data is always better) as well as increasing the processor load. Although Huawei’s homebaked Kirin 960 CPU is more than capable of taking such duties in its stride.

Huawei has entrenched itself as one of the industry leaders in smartphone photography and, in our Pixel-free country, the benchmark for computational photography excellence. Well, until we get more experience with Samsung’s new and improved multiframe processing on the Galaxy S8. - LS PM

The P10’s front-facing camera is now also Leica rated, bringing portrait mode to your face as well as the custom image processing.