4:4:4 10bit single CMOS HD project

[Rob Lohman]

<<<-- Originally posted by Jason Rodriguez : Gosh, I hate to sound like a broken record on this, but that's basically what the Kinetta is.

I'm not trying to say, "don't bother, it's already been done", but if you're going to sink that much cash into a project for all the R&D it's going to take to do FPGA's, etc., then you'd better think of a way to make your solution either much cheaper, or fulfilling a specific niche that the Kinetta doesn't. Because IMHO it makes no sense to spend $20K on a camera that can't do half of what a $30K camera can. That's just the nature of competition. If we can keep the FPGA "hard-disk dumping" solutions below, say approx. $7K (with bundled bayer conversion software), then I'd say very, very nice, you've got sales. -->>>

That might be basically what the Kinetta is, but it's a lot more
expensive. We don't have to pay for programming and research
because we can all do it in our spare time. Yes, time is money,
but in a different way in this case. Yes the chips costs money,
but I don't see how this would go to $20K with what we have
in mind. At least for me personally. I'm not sure where you pulled
those numbers from.

[Les Dit]

The Kinetta looks like it might be a nice product.
What I'd like this threads effort to result in is a system that allows 75% of the camera cost to be sunk into the sensor. Over the longer haul, we might end up with better image quality than them.

[Jason Rodriguez]

Yes the chips costs money,
but I don't see how this would go to $20K with what we have
in mind. At least for me personally

Once we start including ProspectHD/Boxx dual Opteron/big RAID's, etc., then we're talking $$$$. Of course nothing agaist any of these products, I'm just saying that you will quickly find by incorperating these products into the system, the cost will quickly climb.

BTW Obin,

You're latest slo-mo clip didn't seem to have any objectionable artifacts in the way that a rolling shutter would render motion. Also I was doing a study of still camera SLR's and they too are rolling shutter, or focal plane shutter. The only thing was that when shooting at 1/50th of a second for the shutter, I couldn't do the movements you're doing without a lot of motion blur, which basically hid any rolling shutter artifacts if they were even there. So how come your footage has no "natural" motion blur like I'd expect from a motion-picture camera? If that motion blur was there, then maybe there wouldn't be any problems with the rolling shutter artifacts.

[Rob Scott]

Jason wrote:
So how come your footage has no "natural" motion blur like I'd expect from a motion-picture camera?

Are you referring to the young lady with the plastic sheet? I certainly see motion blur in that clip. It looks fairly natural to me, but then I don't have a good eye for this yet.

[Obin Olson]

hmm I am not sure. I still don't have my head around how mhz and shutter speed work on this camera...I understand fps and shutter speed but camera MHZ?? not me..Steve?

I am not sure how you can say you don't see any motion blur?? it's all over that slo-motion stuff!

[Steve Nordhauser]

Obin:
Here is what you are juggling. Camera pixel clock. This sets how long it will take to read out a frame. Also, for the most part, the integration time (shutter speed for each line) can't be larger than a frame time. In rolling shutter cameras, you can reset each line a certain amount prior to readout - less than a frame time if you want a fast shutter speed for minimum motion blur.

You ccould set the integration time very short, slow pixel clock and pan if you wanted to really see rolling shutter artifacts. This would give you minimum motion blur and max artifacts. An artifical test but good when you want to do images of school buses for application notes.

I've been wondering if we are busting our butts trying to emulate film and all its ecentrisities. Is the rolling shutter stuff objectionable or just different? Does it add a feeling of speed? It would crack me up if Lucas adds this effect in a feature film to be different from film effects. Just a thought.

[Rob Lohman]

Steve: well, it's something we aren't used to. So that always looks
out of place. Now the funny thing is that this only happens with
fast moving objects (or camera). In this case we should have
more motion blur, but we don't.

If the integration time is low, the rolling shutter is as well but
we get almost no motion blure. But when we go to a higher
integration time the rolling shutter effect increases but so does
the motion blur?

Jason: I'm not thinking of a dual opteron box with a special
RAID card. As it looks now this will work on a single processor
(nothing fancy) with 1 drive for 8 bit and 2 drives probably for 10
bits in our initial design (at maximum framerates). This is at
1280 x 720. For higher resolutions and 12 bit a third or fourth
drive might be needed. But we aren't at that stage yet (since
this sensor does 1280x720x10bitx60 fps max). We'll do "RAID"
in a software "solution" as it looks... So no need for a fancy
solution there either.

As for ProspectHD. Nothing has been set in stone. If the price
is too high then it is too high...

[Valeriu Campan]

<<<-- Originally posted by Steve Nordhauser :
I've been wondering if we are busting our butts trying to emulate film and all its ecentrisities. Is the rolling shutter stuff objectionable or just different? Does it add a feeling of speed? It would crack me up if Lucas adds this effect in a feature film to be different from film effects. Just a thought. -->>>

A projected fillm without "motion blur", after few minutes becomes unwatchable. The eye is not perfect.
When film standards were set they saw that 30fps was sharper, but only marginally and not justifying the extra production costs, so 24fps was adopted. The motion blur is only a part of the "film look".

[Steve Nordhauser]

Rob L:
The integration time is fairly independent of the readout time except that you can't integrate longer than readout.

To remove rolling shutter you run fast. As you say, this limits the longest integration time (most motion blur).

I did check and we can probably run at 48fps readout time, stretch the vertical blanking so the trash frame doesn't hit the bus. That would mean bursting a frame at about 55Mpix/sec to memory, quiet for a frame time (1/48th sec) followed by the next frame.

The real win here (****drum roll ****) is that now you can integrate during the vertical blanking time. This means a full 1/24th sec integration (motion blur) with fast readout (minimal RS artifact).

I will try to verify this in the next week but my guru on the 1300 said it should work.

[Rob Lohman]

Sounds cool although I will need to think about what you are
saying... Heh. Thanks a lot for your time and please thank
your guru as well! Keep us updated.

It is all MUCH appreciated!

[Obin Olson]

very good stuff Steve, we are only reading 1280x720 framesize so your saying we can do extra stuff with the lost lines of resolution to make the image less rolling shutter effected?

[Steve Nordhauser]

Obin,
Actually, I said something different. There are two types of lines: active lines and blanking lines. When you set the region of interest (ROI) to 1280x720, you are setting the active lines. They will clock out based on the pixel clock. Fast clock, fast readout, minimum RS artifacts.

After the active lines you have blanking lines. For high frame rate you try to minimize this. On the SI-1300, the minimum is 15 rows. No readout but integration occurs. The tricky part is to have the vertical blanking time = 1/48th sec so that frame you are talking about tossing right now is just integration time. Maximum potential motion blur.

We may be able to go even faster. The SI-1300 image degrades if we clock too fast but we have run them up to 67fps at 1280x720. This is 14.9msec per frame. 24fps is 41.67msec per frame so the blanking time could equal 26.75msec per frame. That is the goal. Fastest readout and overall exposure max and frame rate of 24 fps.

Don't worry too much about this. I have to work out what the registers get loaded with and I will pass it on to the Robs.

[Obin Olson]

Oh, I see that is aweomse ! Pass it on asap so the Robs can deal with it in the software in an early version!


Rob did you get your camera yet??

[Juan M. M. Fiebelkorn]

It seems I can't understand this stuff very well...
Steve, did you say that a captured frame would have a 1/24s exposing time (1/24s motion blur)?
If yes, what is the reason for that?
Has something to be with a technical limitation?
I ask these questions because a movie frame at normal speed has an exposure of 1/48s, so a 1/48s motion blur...


P.S. Could someone here contact Xilinx people or post resources for FPGA programming and related stuff (tools, boards, prices,etc)?

[Les Dit]

Here is a way to test the camera for motion blur:
Set up a turn table, or a record player, with a white paper disk and mark on it a line. Take video of that. You will see the frame duration, and the blanking time when you look at the frames.
The line will be blurred for X number of degrees, and the amount of white space between two frames will show the period that the camera is not exposing at all. Can calculate Shutter angle, in film terms.
The rpm of the turntable must be known, obviously.
-Les