4:4:4 12-bit Uncompressed DVX100

September 15th, 2004, 03:03 AM

keep in mind that this a total guess, but... maybe in order to take advantage of pixel shift, you would have to be converting to YUV, like the DSP does (at least i assume it does). if the R, G, and B channels are somehow converted to YUV individually first, and then the Y (luminance) channel of the original G channel is combined with the Y channel of the other two, then maybe it somehow improves image detail. or maybe it's the U and V channels from the G channel that somehow are combined with the other U, V channels, though it seems like that wouldn't make sense. but regardless, i would assume that the utilization of some other color space is a part of the whole pixel shift technology thing.

i read somewhere that the Arriscan film scanner uses pixel shift to obtain a 6k frame using a 3k scanner. maybe someone science-brained can look up the patent info (if that's even possible).

juan, can you post a new raw frame straight from the camera? i have no idea if any of the other frames i have from you have had the green channel adjusted or not.

September 15th, 2004, 03:26 AM

i did a quick search and found these...

http://www.cse.ogi.edu/~linchuan/demosaic/
http://www.cse.ogi.edu/~linchuan/demosaic/adobe-raw.php
http://www-ise.stanford.edu/~tingchen/main.htm

i have no idea if those sites help any, but i know they make my head hurt. maybe someone can write one of those authors a charming email and ask for advice.

Emmanuel Cambier · September 15th, 2004, 04:38 AM

Ok I Tried a search but with no result, so anybody remembers if DVI is in or out ?
I think this could be quiet important.
Take Care
Emmanuel

Juan M. M. Fiebelkorn · September 15th, 2004, 05:27 AM

I forgot a little thing....
I guess that kind of setup would require the use of an anamorphic adapter unless you want to resize the image to anything near the 4:3 aspect ratio after the interpolation...
Cause if the CCD is 794x4XX you will end with 1588x4XX (anything around a 3.3 ratio)

Wayne Morellini · September 15th, 2004, 06:08 AM

DVI is normally output from computers and input on veiwing equipment. I thought I found an AGP 3D card with input, but apparently was wrong on that. We discussed this over at the cinema camera technical thread (I think) and I did post a DVI input board there.

Juan P, thanks for your answers.

If you look at the cinema camera thread (and the obsura cam wiki) you'll get an idea of just how much capture performance you can squeeze out of a computer in HD, which is enough. USB2.0 has a lot more cpu performance hit than IDE and Firewire), and Rob Scott is getting much better capture peformance than expected as he learns more.

Thanks

Wayne.

Robert Martens · September 15th, 2004, 08:44 AM

Yeah, I gotcha. It's the middleman that causes such problems.

Thanks for the explanation!

Juan P. Pertierra · September 15th, 2004, 09:01 AM

Juan(M.):
Remmeber that the DVX's green channel is enlarged in both dimensions, so there is pixel shift in both axes...it's not only shifted horizontally but vertically as well...so the final aspect ratio should be about the same(?)

Juan M. M. Fiebelkorn · September 15th, 2004, 09:46 AM

didn't know that, sorry.
Well, if that is the case, just two possibilities are left.
I could be an amazing high resolution image, or it can be really a mess :)

Herbert Massey · September 15th, 2004, 11:09 AM

I have been reading this forum with great interest. Juan's work looks very cool. However, after waiting for over a month for the website to appear I am begining to wonder if this thing will ever come to fruition.

Any ETA as to when the site will launch?

Thanks

Juan P. Pertierra · September 15th, 2004, 11:46 AM

Please do realize that this is essentially a one-man operation. Opening a company of any size is a huge task, both time-consuming and monetarily. Not to mention the rest of the tasks such as actually BUILDING this.

As of right now I am working on assembling final production hardware.

Juan

Juan P. Pertierra · September 15th, 2004, 11:52 AM

Also, thanks to everyone who posted info on the mosaic approach, it seems that this will indeed work, and I am modifying my code right now to do processing based on this. I think I can get a GREAT ~720P image with this system, while still mantaining the same bandwidth.....very cool. I say ~720P because with the anamorphic adapter the image will be more like 1.83 aspect ratio.

Juan

Herbert Massey · September 15th, 2004, 11:57 AM

Juan,

Sorry be so eager to see something. I'm sure the more work you put into it, the better it will be.

Waiting patiently. Sorta.

Juan P. Pertierra · September 15th, 2004, 12:12 PM

Hey, that's ok...i just want to make clear that i'm not just sitting here idly. There's stuff going on which is critical to doing this correctly and legally. :)

John Alton Disciple · September 18th, 2004, 06:43 PM

Hi all. I haven't posted in a while. I forget - what's the file format that Juan's mod records in? And what software can edit it? For us film out guys, Photoshop isn't a viable nonlinear option. Thanks in advance =)

Juan P. Pertierra · September 18th, 2004, 07:55 PM

Right now it outputs TIFF's, but other formats can be included if needed. For example I have code working for cineon/dpx files as well.

TIFF's can be loaded into FCP as frames if your system is fast enough, or you can create an EDL using DV footage which was recorded while recording in RAW.

Juan

September 15th, 2004, 11:09 AM	#1149
Herbert Massey Tourist Join Date: Sep 2004 Posts: 2	Is this for real? I have been reading this forum with great interest. Juan's work looks very cool. However, after waiting for over a month for the website to appear I am begining to wonder if this thing will ever come to fruition. Any ETA as to when the site will launch? Thanks

September 18th, 2004, 06:43 PM	#1154
John Alton Disciple New Boot Join Date: Jan 2003 Location: El Paso TX Posts: 14	What was the format again? Hi all. I haven't posted in a while. I forget - what's the file format that Juan's mod records in? And what software can edit it? For us film out guys, Photoshop isn't a viable nonlinear option. Thanks in advance =)

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September 15th, 2004, 03:03 AM	#1141
Guest Posts: n/a	keep in mind that this a total guess, but... maybe in order to take advantage of pixel shift, you would have to be converting to YUV, like the DSP does (at least i assume it does). if the R, G, and B channels are somehow converted to YUV individually first, and then the Y (luminance) channel of the original G channel is combined with the Y channel of the other two, then maybe it somehow improves image detail. or maybe it's the U and V channels from the G channel that somehow are combined with the other U, V channels, though it seems like that wouldn't make sense. but regardless, i would assume that the utilization of some other color space is a part of the whole pixel shift technology thing. i read somewhere that the Arriscan film scanner uses pixel shift to obtain a 6k frame using a 3k scanner. maybe someone science-brained can look up the patent info (if that's even possible). juan, can you post a new raw frame straight from the camera? i have no idea if any of the other frames i have from you have had the green channel adjusted or not.

September 15th, 2004, 03:26 AM	#1142
Guest Posts: n/a	i did a quick search and found these... http://www.cse.ogi.edu/~linchuan/demosaic/ http://www.cse.ogi.edu/~linchuan/demosaic/adobe-raw.php http://www-ise.stanford.edu/~tingchen/main.htm i have no idea if those sites help any, but i know they make my head hurt. maybe someone can write one of those authors a charming email and ask for advice.

September 15th, 2004, 04:38 AM	#1143
Emmanuel Cambier Regular Crew Join Date: Feb 2004 Location: Paris, France Posts: 20	Ok I Tried a search but with no result, so anybody remembers if DVI is in or out ? I think this could be quiet important. Take Care Emmanuel

September 15th, 2004, 05:27 AM	#1144
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	I forgot a little thing.... I guess that kind of setup would require the use of an anamorphic adapter unless you want to resize the image to anything near the 4:3 aspect ratio after the interpolation... Cause if the CCD is 794x4XX you will end with 1588x4XX (anything around a 3.3 ratio)

September 15th, 2004, 06:08 AM	#1145
Wayne Morellini Inner Circle Join Date: May 2003 Location: Australia Posts: 2,762	DVI is normally output from computers and input on veiwing equipment. I thought I found an AGP 3D card with input, but apparently was wrong on that. We discussed this over at the cinema camera technical thread (I think) and I did post a DVI input board there. Juan P, thanks for your answers. If you look at the cinema camera thread (and the obsura cam wiki) you'll get an idea of just how much capture performance you can squeeze out of a computer in HD, which is enough. USB2.0 has a lot more cpu performance hit than IDE and Firewire), and Rob Scott is getting much better capture peformance than expected as he learns more. Thanks Wayne.

September 15th, 2004, 08:44 AM	#1146
Robert Martens Major Player Join Date: Jun 2003 Location: Miller Place, NY Posts: 820	Yeah, I gotcha. It's the middleman that causes such problems. Thanks for the explanation!

September 15th, 2004, 09:01 AM	#1147
Juan P. Pertierra Major Player Join Date: Jul 2003 Posts: 479	Juan(M.): Remmeber that the DVX's green channel is enlarged in both dimensions, so there is pixel shift in both axes...it's not only shifted horizontally but vertically as well...so the final aspect ratio should be about the same(?)

September 15th, 2004, 09:46 AM	#1148
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	didn't know that, sorry. Well, if that is the case, just two possibilities are left. I could be an amazing high resolution image, or it can be really a mess :)

September 15th, 2004, 11:46 AM	#1150
Juan P. Pertierra Major Player Join Date: Jul 2003 Posts: 479	Please do realize that this is essentially a one-man operation. Opening a company of any size is a huge task, both time-consuming and monetarily. Not to mention the rest of the tasks such as actually BUILDING this. As of right now I am working on assembling final production hardware. Juan

September 15th, 2004, 11:52 AM	#1151
Juan P. Pertierra Major Player Join Date: Jul 2003 Posts: 479	Also, thanks to everyone who posted info on the mosaic approach, it seems that this will indeed work, and I am modifying my code right now to do processing based on this. I think I can get a GREAT ~720P image with this system, while still mantaining the same bandwidth.....very cool. I say ~720P because with the anamorphic adapter the image will be more like 1.83 aspect ratio. Juan

September 15th, 2004, 11:57 AM	#1152
Herbert Massey Tourist Join Date: Sep 2004 Posts: 2	Juan, Sorry be so eager to see something. I'm sure the more work you put into it, the better it will be. Waiting patiently. Sorta.

September 15th, 2004, 12:12 PM	#1153
Juan P. Pertierra Major Player Join Date: Jul 2003 Posts: 479	Hey, that's ok...i just want to make clear that i'm not just sitting here idly. There's stuff going on which is critical to doing this correctly and legally. :)

September 18th, 2004, 07:55 PM	#1155
Juan P. Pertierra Major Player Join Date: Jul 2003 Posts: 479	Right now it outputs TIFF's, but other formats can be included if needed. For example I have code working for cineon/dpx files as well. TIFF's can be loaded into FCP as frames if your system is fast enough, or you can create an EDL using DV footage which was recorded while recording in RAW. Juan