Home
  • AXIOM Beta
    • Overview
    • Modularity
    • Tech Specs
    • Image Sensors
    • Development Status
    Stay
  • Participate
    • Contributing to apertus°
    • Donate
    • Join the Team
    • Mailinglists
    • Wiki
    • Newsletter
    • IRC
    Stay
  • About
    • Project History
    • apertus°
    • Mission Statement
    • Why Open Source?
    • apertus° Association
    • apertus° Company
    • Team
    • FAQ
    • Sponsors & Benefactors
    • Hardware Contributions
    Stay
  • Contact

Search form

Moving Images from AXIOM Alpha Prototype

Submitted by Sebastian on Wed, 03/19/2014 - 18:00

We have now resolved the issues we were facing with HDMI video recorders. It turns out that monitors are capable of synchronising to whatever frequency you are supplying them with, making them very tolerant and usable straight out of the box - even with non standard signals. Recorders on the other hand are a lot less flexible when it comes to the frequency of the supplied input signals. It appears that they will stubbornly refuse to do anything unless the supplied input frequency is perfect. Unfortunately, the documentation we've found for this is often in contradiction - some sources define this frequency as standard, whilst others will list a different specification. As a result of this confusion, we've ended up cycling through multiple frequencies, adding a few Hz at a time until an image appeared on the HDMI recording device.




the first - not the best one

Please note that this footage contains the first basically unprocessed raw (not in original bayer pattern though) image samples ever recorded with the Axiom Alpha prototype. Whilst this is a major milestone, it represents only our first step through the door and into the beginning of the actual tweaking. Also keep in mind that this is TEST footage not captured with the intent to showcase the capabilities of the camera but rather to proof that it is working at all. While we think you can already see some potential in the image quality the video is simply NOT meant to be beautiful yet. As it stands, the video signal output from the Axiom Alpha still carries some flaws. Let's take a look at them in detail:

We have not yet:
  • calibrated the colours of the camera
  • calibrated the white/black point (offsets) and linearization, leading to some vertical streak/curtain effects
  • created a Fixed Pattern Noise (FPN) profile (the Alpha prototype already supports this, however we have not yet found the time to actually conduct the required measurements)
  • There are some red lines at the bottom of the image, this is due to unresolved minor incompatibilities between the Axiom Alpha HDMI output and the utilized recorder

Due to the limitations of the HDMI encoder chip implemented on the Zedboard, we are currently outputting a rather exotic colour mode: RGB 2:4:2. This has resulted in 1 pixel colour shifts in some situations, visible as red/blue tints around vertical lines. We are currently investigating alternative modes that eliminate this problem. Please also keep in mind that Youtube re-compresses every video that is uploaded, so even when viewing at 1080p, you will still see noticeable compression artifacts irrespective of how crisp the original video upload might be. Since we are still in the process of tweaking and fine-tuning everything, we don't mind these compression artifacts for now. You can rest assured that as soon as we have a greater selection of artistic footage ready to showcase, we will provide access to high quality online video playback / download of these clips.



Fixed Pattern Noise Correction

We have fixed several bugs in the calibration software and can now measure/calibrate the fixed pattern directly inside the camera. The challenge here is that an accurate calibration requires a fully evenly lit image with all colour channels at equal brightness levels. Any slight deviation from this will result in a sub-optimal calibration profile, meaning the FPN corrections can quickly end up creating more artifacts than they are removing. Under optimal conditions, we've witnessed a 100% elimination of the fixed pattern, however for this we've had to create a special device with RGB LEDs controlled by the camera itself, and which is attached to the camera instead of a lens. We are now considering the production of a 3D printed version of this, which we can use/distribute with far greater ease in the future. As a final note on this topic, the correction of the pattern is already running inside the FPGA with 4K footage in real-time.




Smart Dynamic Range Mode

For those of you who may not be aware, our image sensor features an HDR mode called "Piecewise Linear Response (PLR) Mode". This essentially means that you can add two knee-points to the response curve already inside the image sensor, achieving a more logarithmic shaped response curve closer to film negative - with a substantially extended dynamic range in the highlights. Adding knee-points to reduce clipping is common in image processing, however the essential difference here is that not only does it alter the image data after it has been captured but also whilst you are capturing it. As we can save the applied knee-points positions / parameters together with the footage, we can fully reconstruct the linear colour data in post production. Here is the first test we have undertaken with this feature (there are many knobs for tweaking - and we've only just started turning them):


Project: 
AXIOM Alpha

33 Comments

11 years ago
Kimon

Are you kidding?!! I thought

  • Reply

Are you kidding?!! I thought the footage would look really bad the way you described it at the beginning.. This looks awesome already!! Can't believe what you have achieved so far! Can' t wait to see what s coming in the coming months.Awesome work guys!! Keep up the amazing work!

11 years ago
shimin

Totally agree with that, it

  • Reply

Totally agree with that, it looks great and more importantly it looks very filmic.

11 years ago
_gl

Very cool guys, wish I could

  • Reply

Very cool guys, wish I could join in. This kind of tweaking will completely define the character of the thing, and is probably the most fun part (well, when things work anyway : ).

11 years ago
Lee Anthony McIntosh

Super exciting stuff guys!!!

  • Reply

Super exciting stuff guys!!!

11 years ago
Ashkar

" Are you kidding?!! I

  • Reply

" Are you kidding?!! I thought the footage would look really bad the way you described it at the beginning.. This looks awesome already!! Can't believe what you have achieved so far! Can' t wait to see what s coming in the coming months.Awesome work guys!! Keep up the amazing work! "

DITTO :)
Keep up the good work.. all the best from India..

11 years ago
Pietro

Well, if this camera doesn't

  • Reply

Well, if this camera doesn't create a certain very pleasing look right out of the camera, then... well I don't really know what the future of the product will be. There is a number of really affordable RAW cameras out there and what they really lack is a pro-looking output like the Alexas, REDs, Alexas or F35/F55/F65 create right in the RAW.

So I guess be careful what look do you calbrate the camera to ;) The market does not need another mediocre RAW camera ;) RAW is great but it needs to be great from the beginning and not rely 100% on crazy grading.

11 years ago
Cem Kaan Kosali

make high quality reachable

  • Reply

make high quality reachable

11 years ago
Matt

Best of luck guys.

  • Reply

Best of luck guys.

11 years ago
James Skehan

Uhhh, hook me up with a

  • Reply

Uhhh, hook me up with a prototype please!? Footage looks great! I swear I'll film my whole short film on this if I can score s prototype hahaha

11 years ago
Erin

Very, very nice! Looks great

  • Reply

Very, very nice! Looks great for a prototype! Amazing actually. Good Work!

11 years ago
Greg Moore

The Elevator Shot in this is

  • Reply

The Elevator Shot in this is Elegant, It shows the highlight roll off well and it shows the latitude this camera is capable of. You can see so much light gradation from light to dark, dark to light, its like watching milk pour in a bowl of never ending cinema cereal, looks delicious!

11 years ago
zb3r

This camara need to be sub 1k

  • Reply

This camara need to be sub 1k in price to be interesting

11 years ago
Izzy

You guys rock.

  • Reply

You guys rock.

11 years ago
David Peterson

wow, for such early early new

  • Reply

wow, for such early early new footage this is looking good!

@Pietro, these kinds of cameras will of course need a colour grader, or at least somebody who knows the basics.

11 years ago
Beat

Already awesome *raw* results

  • Reply

Already awesome *raw* results, before even starting seriously calibration! Great stuff! The road is long, but exciting and the goal is now reachable! Keep open source and open hardware rocking!

11 years ago
Dbobs

That footage looks great. I'm

  • Reply

That footage looks great. I'm really excited by this camera. Keep up the good work! I hope this camera is available by the time we decide to upgrade to 4k.

11 years ago
Sander Bontje

Amazing looks for a few

  • Reply

Amazing looks for a few uncalibrated first shots right out of the box! Love the PLR mode. And the global shutter.

11 years ago
HOLY SHIT

WOOOOOW! WHAT IS THE PRICE??

  • Reply

WOOOOOW! WHAT IS THE PRICE??

11 years ago
Sid Paker

Congratulations can't wait to

  • Reply

Congratulations can't wait to see the final product ! It looks Famtastic !

11 years ago
Napelazam

Can i work for you? I will do

  • Reply

Can i work for you? I will do my best for this baby!

11 years ago
Sebastian

Sure! Check this page: https:

  • Reply

Sure! Check this page: https://apertus.org/contribute

11 years ago
Remoran

Your video looks awesome.

  • Reply

Your video looks awesome. Outstanding for alpha output. Keep it up.

Best

11 years ago
Eddie

Been following the progress

  • Reply

Been following the progress of the axiom since it was first announced and I'm happy for you guys and I'm glad to see the progress! Two questions though. Did you use PLR for the test shots and what "stop setting" did you use for the test? It looked like you were getting at least 12-13.5 clean stops. Amazing progress.

11 years ago
Scott Kessler

I agree! It's always one step

  • Reply

I agree! It's always one step at a time, and you should be proud as this is an historic milestone toward your goals. Keep at it!!

11 years ago
fssfs

Good video footage, looks

  • Reply

Good video footage, looks like things are working out.

When this camera is 'finished' would like to have a raw recording mode with as little calibration as possible.

Considering your troubles with the HDMI video recorders, an open source HDMI video recorder might be very interesting. One that detects and adjusts to the HDMI video input frequency. One that is user friendly, easy and allows you to work fast without having to constantly spend time on repetitive tasks or details.

Would love such a device to record screen for tutorials and machinima.
An open source HDMI video recorder could be really successful. Please consider adding this to your open source projects.

11 years ago
Alex

The details in the shadows

  • Reply

The details in the shadows look great. A wide dynamic range is evident. You are definitely on the right track.

11 years ago
Tzedekh

A few random comments . . .

  • Reply

A few random comments . . .

Regarding the "under $10K" price point, considering that there are now three CMV12000-based cameras (two by Blackmagic Design and one by AJA) well under $10K on the horizon, maybe you should rethink pricing. Unless it's well below $10K -- below $6K, even -- it might have a problem competing.

Somewhere I believe I read that you are attempting to send raw over HDMI. Is this even supported under the HDMI spec, or are you wrapping the raw image data in something that HDMI supports? Is HDMI version 2.0? With respect to raw, I suggest a wavelet-compression scheme comparable to CineForm RAW. Uncompressed raw will be too onerous.

Regarding the image sensors, have you considered having it made by Alternative Vision Corp. (http://www.alt-vision.com)? Of course, it would need to be a custom design -- that is what they do -- but it could theoretically be better and cheaper than the off-the-shelf chips available, including the CMV12000.

11 years ago
Sebastian

AXIOM Beta will be around 1 -

  • Reply

AXIOM Beta will be around 1 - 2K€ depending on configuration, check the details here: https://apertus.org/2014-NAB-Axiom-Beta.

We will experiment with raw over HDMI, the protocol itself will follow the standard but the image content likely wont.

Custom image sensor design starts at around 2 million $, slightly out of our financial reach a the moment... :)

11 years ago
marley

When can i buy an Alpha?

  • Reply

When can i buy an Alpha?

10 years ago
arah

when this camera will be

  • Reply

when this camera will be published

10 years ago
Sebastian

The successor camera AXIOM

  • Reply

The successor camera AXIOM Beta is now crowd funding: https://www.indiegogo.com/projects/axiom-beta-the-first-open-digital-cin...

10 years ago
Giridhar Rajput

where can i find the

  • Reply

where can i find the schematics and components and software details of Alpha version??!!!

10 years ago
Sebastian

https://wiki.apertus.org

  • Reply

https://wiki.apertus.org/index.php?title=AXIOM_Alpha
https://wiki.apertus.org/index.php?title=AXIOM_Alpha_Software
https://github.com/apertus-open-source-cinema/alpha-software
https://github.com/apertus-open-source-cinema/alpha-hardware

Add new comment

More information about text formats

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
apertus° is a member of Free Software Foundation Europe and the AXIOM project is certified Open Hardware by Open Source Hardware Association .
apertus Logo
apertus° - open source cinema BV
Wolstraat 21
2000 Antwerp
Belgium
Contact
Contribute
Join the team GitHub repositories Live chat (IRC) Donate
Projects
AXIOM Beta AXIOM Remote
Association
About Contact Team Mission Statement Project Background
apertus° Association
Mortaraplatz 11
1200 Vienna
Austria
Association Details
AXIOM Camera Project Brochure Download:
AXIOM Beta Brochure
Resources
Wiki Regional communities Social media accounts Imprint Privacy Policy
For occasional project updates:
Subscribe to our newsletter


Github Icon Twitter Icon Mastodon Icon Wiki Icon Login Icon Login
Thanks to our Sponsors
© apertus° community 2006-2025
Website content available under CC-BY 4.0 International license