Is Oversampling a marketing gimmick?

[Moiz Mian]

So I found out the other day that oversampling is a very basic algorithm which averages surrounding pixels to make a sharper smaller picture.

What I mean is, on your laptop, assume you have a 1080p display. That's 2MP. If you take a picture that is 8MP, and display it zoomed out, the computer is automatically oversampling it to 2MP.

So if you have a 41mp picture that you took on your Lumia 1020, and just shrink it down to 5MP in windows photo viewer, the image quality be the same as the Nokia oversampled 5MP picture? Can someone try this? Or has someone tried this? It would be nice if Nokia was doing some kind of magic with their oversampling, or if it's just the same as zooming out on a picture in a photo viewer.

Thanks!

 

[vlad0]

No, its not the same.

This technology has been around for over two years already. It was introduced in February of 2012 in a device called 808 PureView, and there has been plenty of discussion on how it actually works.

Based on this review:

Test du Nokia 808 PureView : Photos, Vid?os | Test-Mobile.fr

Nokia used something very similar to this: Lanczos resampling - Wikipedia, the free encyclopedia

"Le r?sultat produit par un redimensionnement sur PC des images haute d?finition (en utilisant l’algorithme de resampling Lanczos) est sensiblement comparable ? ce que le 808 PureView fait en temps reel"

"The result produced by resizing PC high definition images (using Lanczos resampling algorithm) is substantially similar to what the 808 PureView in real time"

You can take a 41mpix photo and resample with it and you will get a similar results, but still not as good.. at least from my own experience. But its good if you want to achieve a similar effect at a higher resolution like 12-15Mpix, which are not natively supported by the phone.

There is an ongoing debate if the Lumia 1020 uses this same technology.. on board DSP processing vs. software processing, etc. there is a whole thread on it.

 

[Moiz Mian]

No, its not the same.

This technology has been around for over two years already. It was introduced in February of 2012 in a device called 808 PureView, and there has been plenty of discussion on how it actually works.

Based on this review:

Test du Nokia 808 PureView : Photos, Vid?os | Test-Mobile.fr

Nokia used something very similar to this: Lanczos resampling - Wikipedia, the free encyclopedia

"Le r?sultat produit par un redimensionnement sur PC des images haute d?finition (en utilisant l’algorithme de resampling Lanczos) est sensiblement comparable ? ce que le 808 PureView fait en temps reel"

"The result produced by resizing PC high definition images (using Lanczos resampling algorithm) is substantially similar to what the 808 PureView in real time"

You can take a 41mpix photo and resample with it and you will get a similar results, but still not as good.. at least from my own experience. But its good if you want to achieve a similar effect at a higher resolution like 12-15Mpix, which are not natively supported by the phone.

There is an ongoing debate if the Lumia 1020 uses this same technology.. on board DSP processing vs. software processing, etc. there is a whole thread on it.

Ok, thanks for that! So it sounds like they compared the image quality of lanczos to what the 808 does and it was similar? What does standard resizing do? Is there a big difference between lanczos and the standard resizing in windows? And I guess you're saying no one knows if the 1020 uses the same technology. Do you have the link to the thread?

Thanks!

 

[mister2d]

It's also a way that the Hubble telescope takes its images. Oversampling is a technique that is used.

 

[Moiz Mian]

It's also a way that the Hubble telescope takes its images. Oversampling is a technique that is used.

My point is, resizing images on your computer uses the same technology, so there is nothing special here. I can take the 41mp image, zoom out and get the same quality as the "oversampled" image

 

[vlad0]

The algorithms are probably very similar, where the Nokia one on the 808 shines is in low light.. it seems to clean the noise in a more efficient manner than any post resizing algorithms that I've tried so far.

But if you are asking if you are going to see a huge difference b/w the two in daylight conditions, no.. not really.

What matters here is the size of the sensor, the rest is secondary.. the 1020 has a relatively huge sensor, and from that point on whatever you do you will get a better results compared to a phone with a smaller sensor.

 

[JustToClarify]

it's a real thing on 808 and marketing gimmick on 1020, it's like difference between hardware and software acceleration in video games..if you can remember those times

 

[mister2d]

My point is, resizing images on your computer uses the same technology, so there is nothing special here. I can take the 41mp image, zoom out and get the same quality as the "oversampled" image

Ok. So what if you zoom in on the picture? The whole point on the 808 was for lossless zoom without digital noise, and a huge optical zoom lenses on your cell phone. Nokia used engineering creativity to bring that technology to a pocketable device.

 

[Moiz Mian]

Ok. So what if you zoom in on the picture? The whole point on the 808 was for lossless zoom without digital noise, and a huge optical zoom lenses on your cell phone. Nokia used engineering creativity to bring that technology to a pocketable device.

I think you're thinking about something different. One of the marketing gag words thrown around is "oversampling". This allows you to take a smaller zoomed out picture at 5mp. 41mp is zoomed all the way in to 1:1 pixels. 5mp is zoomed out to 1:7 pixels. So that fancy oversampled 5mp photo is little more than zooming out on the 41mp photo

 

[mister2d]

I think you're thinking about something different. One of the marketing gag words thrown around is "oversampling". This allows you to take a smaller zoomed out picture at 5mp. 41mp is zoomed all the way in to 1:1 pixels. 5mp is zoomed out to 1:7 pixels. So that fancy oversampled 5mp photo is little more than zooming out on the 41mp photo

Nope. Don't think I'm referring to anything else than what I said.

 

[Moiz Mian]

Nope. Don't think I'm referring to anything else than what I said.

I hate to be the bearer of bad news, but there is no such thing as "lossless zoom". That is REALLY a marketing gimmick. Digital zoom can not replace optical zoom. The quality is lost when you zoom even on the 808 or 1020

 

[vlad0]

I hate to be the bearer of bad news, but there is no such thing as "lossless zoom". That is REALLY a marketing gimmick. Digital zoom can not replace optical zoom. The quality is lost when you zoom even on the 808 or 1020

Correct, to a certain extend.

It is a better implementation that the conventional digital zoom which basically "creates" pixels out of nothing to compensate when you zoom, its still not as good as optical. There are certain things that are interesting.. like for example the cropping method keeps the same aperture no matter the zoom range, where with mechanical the more you zoom, the less light reaches the sensor.

Its a very elegant solution for mobile phones, all you need is a big enough sensor and enough processing power to read all the pixels from the sensor, and not just a fraction like almost every smartphone out there excluding the N8, 808, and possibly the 1020.

I find the Nokia "lossless" zoom to be most effective for video recording..

it's a real thing on 808 and marketing gimmick on 1020, it's like difference between hardware and software acceleration in video games..if you can remember those times

are we 100% sure on that ? I lost track of it

 

[Kryakus]

are we 100% sure on that ? I lost track of it

808 use dedicated image processing chip for PureView oversampling.
1020 use cpu/gpu for PureView oversampling.

Both phones use raw data from sensor for oversampling.

It's not a "marketing gimmick" at all on 1020, PureView works just as it should but oversampling algorythm is worse than on 808. Lumia Black update should make it way better.

 

[LumiaChemist]

The method of oversampling is the important part of this problem.
"zoom out" in your standart photo viewer is a nearest neighbour algorithm, which doesnt average pixels at all.
You see that, if you zoom into the picture, eventually you see the pixel as squares.
The 1020 probably uses a bicubic algorithm with sharpening at the end.
This sharpening at the 5 MP level is also the sorce of the heavy graininess.

"The goal of combing many images into one is only to increase the SNR. The resulting images are neither more luminous or more colorful but they contain much less noise which will let you stretch the histogram a lot more which will give you more freedom to bring back colors and details." (The theory or How to create better images)
The same goes for oversampling, when you average 7 pixels into 1, you increase your PSNR by approximately 2,64dB.

 

[vlad0]

Lumia Black update should make it way better.

From what I can see on the 1520, that's pretty much a certainty. The 1520 photos look more "Symbian like" than WP like.. which is a very good thing.

 

[Christer Sjaunja]

Read this:
Pixel Binning, does it work? | Life in Megapixels

, especially the last part on "Can it still work"., In short, post processing wont do much but real time processing when done during capture (which is how it is explained in the white paper for Nokia 808) will improve image quality, especially noise compared to post processing.
In the whitepaper for 1020 the reference is that they used "the technology from 808" ie pureview 1st edition and improved it. If that means that its real time processing is unclear...
Some more info:
http://www.olympusmicro.com/primer/digitalimaging/concepts/binning.html

 

[Moiz Mian]

Correct, to a certain extend.

It is a better implementation that the conventional digital zoom which basically "creates" pixels out of nothing to compensate when you zoom, its still not as good as optical. There are certain things that are interesting.. like for example the cropping method keeps the same aperture no matter the zoom range, where with mechanical the more you zoom, the less light reaches the sensor.

Its a very elegant solution for mobile phones, all you need is a big enough sensor and enough processing power to read all the pixels from the sensor, and not just a fraction like almost every smartphone out there excluding the N8, 808, and possibly the 1020.

I find the Nokia "lossless" zoom to be most effective for video recording..



are we 100% sure on that ? I lost track of it

You're right, i think the zoom makes more of an impact in video recording, since it is still 1080p and probably still sampled.

 

[sakendrick]

Where's the magic??

I understand images and pixels and the theory behind the 41 Megapixel zoom - but end of the day I don't get good pictures using their "reinvented zoom" at all. Has anyone actually achieved good photos by zooming?...I don't think I'm expecting an unreasonable distance of zoom, but when I snap, then zoom, all the pictures look fuzzy - not exactly the same as pixelated, but just fuzzy. My thought is that if you don't have the lens to accurately capture all those pixels, it's not going to look good when you zoom.

It's funny because we were just at my daughter's xmas pageant, stuck at the back. I thought I was living the commercial and showing off my 1020 ability. All my pictures were garbage after cropping post photo and so i ended up fighting other parents to get a better view. It even seemed like some of the parents with iphones/androids were getting better pictures using zoom.

Or am I doing something wrong? (I zoom while in Nokia Pro Camera app, or I grab the picture from gallery, clink the link to the pro camera and edit.

 

[Blacklac]

If its fuzzy, there's a good chance you weren't steady enough. Steadiness (or lack there of)really shows in zoomed images. Try with a tripod or securing yourself by resting your arms on an object and using the timer to snap a shot and see if its better. Also, try lowering the shutter as much as you can.

 

[vlad0]

Re: Where's the magic??

Has anyone actually achieved good photos by zooming.

Its not really zooming.. its just cropping in real time, which is still better than "traditional" digital zoom ..