Huawei P40 Pro Super Resolution Zoom: How Good It Is and How Much Better It Could Be

The Huawei P40 Pro looks like the winner in the smartphone zoom race, achieving DxOMark Zoom Score of 115, the all-time high. However, its outstanding camera hardware, utilizing a 125mm f/3.4 telephoto module, is not the only key to success. Achieving the best results would not be possible without using a computational super resolution zoom technology. We did some testing to check how good it is and if better results could be achieved if using the leading Super Resolution technology from Almalence.

We will start with a side-by-side comparison and then discuss some interesting features of Huawei’s SR which we found during the testing. For the testing, we captured:

  • several JPEG images with the built-in camera app at 10x, those came out pretty different so we used the best one for comparison;
  • a series of RAW images with the 5x telephoto camera module, which were then processed with 2x Almalence Super Resolution.

The pictures were captured indoor, in good office lighting (~700 Lux). Note, as we used RAW images for processing, the colors in Almalence SR output are somewhat off.

Comparing the ability to resolve fine details shows a dramatic improvement when using Almalence Super Resolution Zoom:

Left: Huawei P40 Pro built-in 10x zoom; Right: Almalence Super Resolution Zoom

A strange effect in the next example, most of the fine text is “washed out” in the P40 Pro image. That can be caused by extreme noise filtering or input frames misalignment/deghosting.
Also note the highlighted character. It looks like Huawei’s algorithm employs a kind of a neural network, which tried to “guess” the object but in this case made a wrong guess. (We will show more examples of that NN’s job below)

Left: Huawei P40 Pro built-in 10x zoom; Right: Almalence Super Resolution Zoom

A testing with a wedge chart, Almalence SR Zoom increases the effective resolution by ~20..25% more than Huawei’s built-in algorithm:

Left: Huawei P40 Pro built-in 10x zoom; Right: Almalence Super Resolution Zoom

Getting back to the P40 Pro’s [supposedly] neural network, an interesting example below. First of all, the NN did an absolutely fantastic job resolving the hair (look at the areas 1 and 2). This looks like something beyond the normal capabilities of super resolution algorithms, which makes us convinced a neural network was involved. Exploring the image further, however, we can see that in some areas (e.g. area 3) the picture looks very detailed but actually unnatural (and yes, different from the original), so the NN made a visually nice, but actually a wrong guess. In the area 4, the algorithm “resolved” the eye in a way that it distorted the eyelid and iris geometry, making the two eyes looking at different directions; it also guessed the bottom eyelashes in a way that they look like growing from the eyeball, not the eyelid, which looks rather unnatural.

Left: Huawei P40 Pro built-in 10x zoom; Right: Almalence Super Resolution Zoom.
Huawei’s result looks more detailed, however in some areas those details are unnatural and do not reflect the original object.

To summarize, while the Huawei P40 Pro is clearly the winner in telephoto camera module hardware design, its computational zoom algorithm is not yet doing the best possible job. While having some advantages over Almalence’s Super Resolution Zoom in resolving certain kinds of objects, it could be better in terms of overall resolution capability. It would be really interesting to see what those algorithms could do if combined together, likely that would make an all-time best digital zoom technology.

A Zoom Technology Missing from iPhone 11 Pro

Despite having a telephoto camera module, iPhone 11 Pro zoom is still far behind the top performers which use Super Resolution Zoom.

Zoom has recently become one of the most important features of smartphone cameras with the leading OEMs advertising their devices achieving high picture quality at sometimes crazy zoom levels.

As every high-end smartphone, iPhone 11 Pro uses a dedicated telephoto camera module to achieve the maximum zoom quality. It appears however, that simply utilizing a telephoto module, even of a great design and quality which is undoubtedly the case with an Apple’s product, is not enough to achieve the top zoom performance. According to the DxOMark benchmark, iPhone 11 Pro achieves Zoom Score of 74 while, for example, Xiaomi Mi 10 Pro hits 110, a drastic 1.5x difference!

To go beyond the camera hardware capabilities, top Zoom performers utilize a computational imaging technique, Super Resolution Zoom. As its name suggests, it uses super resolution technique to increase the resolution of the images suffering from the lack of pixels in case the target zoom level exceeds the optical zoom of the telephoto module.

For example: zooming 4x with a 12 MP 2x telephoto module uses only 1/4 of its sensor, or just 3 Megapixels.

Besides improving the resolution, Super Resolution Zoom also increases the SNR, lost due to small aperture of a telephoto module, the higher the optical zoom level – the smaller is the aperture.

We made a few tests to check how Almalence Super Resolution Zoom, the most advanced digital zoom technology, would improve iPhone 11 Pro zooming capabilities. Check a couple of examples below:

iPhone 11 Pro, 4x zoom. Left: iPhone as is, Right: with Almalence Super Resolution Zoom

iPhone 11 Pro, 4x zoom. Left: iPhone as is, Right: with Almalence Super Resolution Zoom

The pictures speak for themselves. Apple can definitely achieve better zoom picture clarity by utilizing a computational super resolution technology.

Almalence Digital Lens to harness the full potential of Varjo’s human-eye resolution head-mounted display

From its beginning Varjo positioned itself as the leader of VR head-mounted displays megapixel race. Their “human-eye resolution” VR-1 truly shows more detail than any other existing HMD.

However, just offering a high pixel count does not mean the user will be able to see a crisp and clean picture through the HMD optics, and in fact, it is the optics which present a display quality bottleneck. In a head-mounted display there are severe design constraints especially in making the optics light weight and fit in a tight space. Those constraints lead to a compromised optical performance, resulting in color fringing and blur. Moreover, any movement of the eye pupil, which itself constitutes a lens element, makes the entire optical system quite different from the original optical design, so the blur and color fringing get even stronger as the eye looks off the optical axis.

Almalence Digital Lens is a computational lens aberrations correction solution which overcomes these limitations by compensating the aberrations of an HMD optics. It does the job of a corrective lens element which dynamically adjusts its properties depending on the eye pupil position. We were eager to check how that technology can improve picture clarity of the highest resolution HMD.

Note 1: This testing was performed by Almalence independently from Varjo. The Digital Lens test was implemented as a Unity application using public API.

Note 2: This is the very first testing, definitely showing sub-optimal results. We see a clear way to further improve the image clarity with the given headset.

We used a construction drawing as a test picture as it clearly demonstrates how the insufficient apparent resolution and clarity limit the VR usability.

The test picture

To take the images within the HMD, we used our camera system with our eye imitator, allowing to capture what a human eye would see.

In the first example the eye looks about 10 degrees off the center. The left part of the gaze area falls onto the high resolution “focus display”, the right part falls onto the lower resolution “context display”

Move the slider left/right to see the difference. Left: Varjo VR-1 as is; Right: VR-1 with Digital Lens. Despite the high display pixel count, the picture does not look very clear. One can even start feeling sick when trying to read the numbers. The very same display with the Digital Lens delivers much clearer and readable picture.

In the next example the eye looks straight at the center, along the optical axis – the ideal case in which the HMD delivers its highest possible picture quality. The gaze area is completely over the focus display. Even in that case the Digital Lens shows a noticeable improvement:

Left: Varjo VR-1 as is; Right: VR-1 with the Digital Lens. Same display, but more legible text and crisper lines.

The beauty of the Digital Lens solution is that it is a pure computational technique, adding no extra size, weight or mechanical complexity to the device.

As mentioned above, those are very first tests, more to follow. However the tests already prove that the Digital Lens is an indispensable technology for high-end VR headsets, allowing to harness the full potential of high display pixel count and density.

Google Super Resolution Zoom: Good Start but not There Yet

Our first testing of Google’s super resolution zoom recently announced in Pixel 3 shows that it indeed can restore some image details, but is still behind the best in class solutions.

Comparing to the “normal” digital zoom, which is basically an upscaling plus edge enhancement, Google’s zoom reveals some details that are indistinguishable in the “normal” image:

However, it’s still not the best of what super resolution can achieve. Below is a comparison of Google’s super resolution zoom to Almalence SuperSensor, a technique based on multi-frame super resolution, running on the same Pixel 3 smartphone:

It looks like Almalence SuperSensor is closer to be delivering on the “optical zoom” promise.

Another nice example captured when taking zoomed images of a book on optical design. Google super resolution makes the text somewhat better readable, however some characters still remain distorted beyond any possibility to recognize them. Also some minor color artefacts are introduced on the originally black text:

And again, if you really want to capture a readable text, Almalence SuperSensor is a solution (note that SuperSensor also got the white color of paper right):

Unfortunately, there is no way to reliably measure the Google’s super resolution processing time. It looks like the processing is performed in background. When trying to quickly open the image right after its icon appears in the camera app, the preview would still show a progress sign for a fraction of a second, probably implying that the image is still being processed. One can feel that the processing takes roughly one second altogether, but there is no way to verify that number. Almalence SuperSensor processing takes 200-500 ms on the same hardware (SnapDragon 845).

The full images used to make the above comparison examples are available in an archive below. Note: for accurate comparison the images of each scene were taken with the same Pixel 3 smartphone, from the same position under the same lighting. The zoom level might slightly differ between images as there is no way to precisely set the zoom factor in the Pixel 3 camera app. The Pixel 3 camera app, updated to the recent version as of Jan 25, 2018, was set to “HDR+” mode.

PS Stay tuned, we will soon show a comparison of super resolution zoom at video frame rates!

Google Super Resolution Zoom: Good Start but Long Way to Go

Please read the updated post.

After publishing this original post we were contacted by Google engineers who pointed to the fact that Super Res was not always on in the images we took. Of course, it happened unintentionally, there’s just no obvious way to make sure that Super Res kicks in when taking an image.

We have re-taken the test images as suggested by Google and we admit the results are much better now. However Almalence SuperSensor is still superior :).

Accurate Eye Imitation for VR HMD Testing

When it comes to VR/AR HMD objective testing, you need an “eye” which is much more than simply a digital camera. Besides having the entrance pupil, focal length and aperture similar to those of a human eye to see like a human eye, the imitation must be properly perceived by the eye tracking modules.

Meet the First in the World accurate eye imitation created by Almalence.

Not only sees like an eye, but also looks like an eye

Using a special compound developed at Almalence lab, we managed to create an imitation of the iris that looks correctly in both visible and infrared light, which makes the eye imitation correctly detected by eye tracking devices. To make the imitation totally indistinguishable from an eye of a human being, the imitation is made to give proper reflections and glint locations.

Whist having all the above properties, the imitation has a cover glass made of an optical-quality transparent material, which does not distort the light passing to the camera. The camera, in its turn, has the entrance pupil properly positioned within the “eye” using special micro-mount.

With the above features together, we have achieved a perfect “two-way immersion” — the eye imitation not only sees exactly what a human eye would see, it also looks exactly as a human eye to the eye tracker.

The eye imitation will be used for better optical profiling of VR HMDs to achieve the highest possible quality with Almalence Digital Lens technology and for accurate objective testing of VR/AR HMD picture quality.

This eye does not lie

Almalence Digital Lens technology enables high resolution wide FoV VR HMDs

Digital Lens addresses the smear and aberrations inherent to thin and lightweight VR HMD optics.

First objective quality measurements performed with a demo based on HTC Vive showed up to 2.7 times effective resolution improvement and suppression of chromatic aberrations even at the edges of field of view.

The technology opens the door for high resolution displays, solving the problem of optical performance which does not allow to harness the full advantage of extra display resolution. It also enables wide field of view HMDs where any acceptable picture quality at wide angles cannot be achieved with an optical design alone.
Aberration and MTF charts from the report on quality measurement, comparing HTC Vive built-in lens correction to Almalence Digital Lens:

MTF50, HTC Vive with/without Almalence DLVR

MTF50, HTC Vive with/without Almalence DLVR


Almalence DLVR removes chromatic aberrations in HTC Vive even at the edges of field of view

Almalence DLVR removes chromatic aberrations in HTC Vive even at the edges of field of view


HTC Vive with/without Almalence DLVR, slanted edge chart for Imatest measurements

HTC Vive with/without Almalence DLVR, slanted edge chart for Imatest measurements

Meet us at Mobile World Congress 2018

This year we will bring to MWC:

  • A live demo of our breakthrough VR quality improvement technology. An enabler for next generation high resolution HMDs, Almalence DLVR technology solves the problem of thin and lightweight optics quality without adding extra size or weight to VR/AR HMDs
  • Latest generation of mobile image and video improvement solutions. High resolution, lossless zoom, better low light performance and higher dynamic range plus image stabilization altogether in a single solution, available for both still image capturing and video/preview!
  • Next generation image and video improvement technologies to be brought to the market in 2018

Demo by invitation only. Please contact us to schedule a meeting.

Almalence in the Press

Forbes: This Imaging Software Startup Is Defining The Future Of Digital Cameras

Almalence is taking an innovative approach to actively disrupting the industry, using algorithms to improve photo quality at unprecedented speeds, setting the standard for how digital imagery is imagined for the future.

What You Don’t Know About Your Phone’s Camera and How it is Changing

A few years ago software was considered as something additional/extra/optional and now it’s an integral, indispensable part of a camera subsystem. Sometimes the design of a new mobile phone model camera starts with looking at the software and then selecting the hardware.

Are Smartphone Cameras About to Become Way Cooler

…the top line smartphones have certainly upgraded the equipment (sensors) in the cameras, but the biggest quality difference has been achieved by software.

Almalence and the Future of Mobile Phone Cameras

The software onboard smartphones today is revolutionary. The ability to take pictures in low light, digitally zoom (or crop) without significant resolution loss, and capture moving objects without blur is in large part a function of software, not hardware. In fact many smartphone cameras are designed from the ground up based on software requirements.

xTeleZoom extends the lossless zoom range of iPhone 7+ dual camera

Computational imaging technology increases the resolution and enables high quality zoom beyond iPhone 7+ 2x telephoto camera hardware.

February 27, 2017. Barcelona.
Today at Mobile World Congress, Almalence, the leader in computational imaging technologies announced its xTeleZoom app for the iPhone, enabling extra high quality zoom capability. Using a sophisticated computational technique, the app is able to dramatically preserve resolution and suppress the noise while zooming.

Mobile phone photography is still limited in its ability to zoom in without sacrificing resolution and image detail. While there is no practical way to create an optical zoom solution in mobile form factor constraints, the phone makers, including Apple, add an extra telephoto camera to their devices to provide good zoom quality. This approach, however, is able to provide only a limited optical zoom factor as the longer focal length lenses in mobile size constraints suffer from decreased aperture, resulting in low resolution and high noise level.

“We developed xTeleZoom because even the most advanced hardware solutions alone cannot address the need for taking high quality zoom photos”, said Eugene Panich, CEO of Almalence. “The decreasing thickness of new phone generations poses bigger challenges on the lenses ability to zoom and resolve good image quality. Software like xTeleZoom is the only practical way to break the zoom quality barrier”.

Almalence’s xTeleZoom uses computational imaging technology that enables better zoom shots from the iPhone without compromised image quality. Originally developed for professional photography it’s now available as an iPhone app to extend the high quality zoom range of the telephoto camera of the iPhone 7+. The users of the iPhone 6, iPhone 6s and iPhone 7 models without a tele camera will also benefit from higher quality zoom using the xTeleZoom app.

xTeleZoom is available on iTunes for $.99: https://itunes.apple.com/us/app/xtele-zoom/id1189050574

xTeleZoom enables lossless zoom for iPhone

About Almalence
Almalence, an Intel Portfolio Company, is the global leader in computational imaging technologies used in a wide range of optical systems from high-end DSLR cameras to mobile phones. Almalence’s solutions are licensed by top smartphone OEMs. Almalence Inc. is a privately owned company with headquarters in Austin, Texas and the team distributed across the world – USA, Russia, Israel, China, and South Korea. For more information about Almalence technologies please visit www.almalence.com.