hvx200 pixel count revealed at DVinfo.net

Jaser Stockert · February 25th, 2006, 01:01 AM

http://www.dvxuser.com/V6/showthread.php?t=47570

looks like steve mullen nailed it!

Barry Green · February 25th, 2006, 03:38 AM

Yeah, you gotta hand it to Steve, he figured it out down to the pixel. Well done, Mr. Mullen.

Thomas Smet · February 25th, 2006, 08:07 AM

The interesting thing about using pixel shift is that there is no way that the HD video could have 4:2:2 color.

Even Juan said from Andromeda that he never claimed his device gave 4:4:4 in HD modes because the color channels alternate every other pixel. He wasn't sure really what to call it but it is more like a 4:2:? that might actually be closer to a 4:2:0 but without the skipping of the every other line lick in mpeg2 4:2:0. Youwould have true blocks of color that are 2x2 pixels in size but not 2x1 pixels like in a true 4:2:2.

Yes the format records 4:2:2 but the source is not 4:2:2.

Yes it is still slightly better than HDV but not like compaing 4:2:0 to 4:2:2. If the 4:2:2 was the main reason for somebody getting the camera they may have to think about this a little bit more.

With the HVX200 even if you went analog uncompressed the HD is still pixel shifted to give this chroma reduction. With any other HDV camera and analog uncompressed at least you are getting a true 4:2:2.

Stephen L. Noe · February 25th, 2006, 10:20 AM

Thomas, I'm right there with you in that thought.

Quote:

Originally Posted by Thomas Smet

The interesting thing about using pixel shift is that there is no way that the HD video could have 4:2:2 color.

Even Juan said from Andromeda that he never claimed his device gave 4:4:4 in HD modes because the color channels alternate every other pixel. He wasn't sure really what to call it but it is more like a 4:2:? that might actually be closer to a 4:2:0 but without the skipping of the every other line lick in mpeg2 4:2:0. Youwould have true blocks of color that are 2x2 pixels in size but not 2x1 pixels like in a true 4:2:2.

Yes the format records 4:2:2 but the source is not 4:2:2.

Yes it is still slightly better than HDV but not like compaing 4:2:0 to 4:2:2. If the 4:2:2 was the main reason for somebody getting the camera they may have to think about this a little bit more.

With the HVX200 even if you went analog uncompressed the HD is still pixel shifted to give this chroma reduction. With any other HDV camera and analog uncompressed at least you are getting a true 4:2:2.

Jarred Land · February 25th, 2006, 10:38 AM

yeah.. a few people got it.. my favorite was the guys that took it apart and used a microscope to count the pixels. :)

Barlow Elton · February 25th, 2006, 11:57 AM

Quote:

Originally Posted by Thomas Smet

The interesting thing about using pixel shift is that there is no way that the HD video could have 4:2:2 color.

So how is it that the Canon has SDI 4.2.2 color, but employs horizontal pixel shift? Is it because it's only in one axis?

Chris Hurd · February 25th, 2006, 12:11 PM

Pixel Shift in the XL H1 is indeed horizontal axis only.

Giroud Francois · February 25th, 2006, 12:44 PM

So we enter in a new bad era for video camera , virtual pixel.
now camera can advertise any resolution (or pixel count) regardless to the real one on the CCD.
very sad in fact....

Pete Bauer · February 25th, 2006, 12:53 PM

Barlow, not sure I'm exactly answering your question and I'm no tech expert, so those who are may want to amplify/correct, but I'll take a stab at it...

Just as with the Panasonic, the format of the HD-SDI out (4:2:2) has nothing to do with how the signal was obtained within the CCD block or the original detail before processing. It is simply a particular kind of output; the luma and chroma detail within the CCD block get processed, and output in either SDI or HDV, or both. Same with HDV...the 4:2:0 is simply the HDV spec'ed output of the processed signal from the CCD block. So the chroma DETAIL might not quite as sharp as it would be from a true 1920x1080 4:2:2 or 4:4:4 source, but the signal is still 1920x1080 at 4:2:2

Thomas Smet · February 25th, 2006, 12:55 PM

yes horizontal is fine for 4:2:2 since you take only every other horizontal chroma sample. You end up with a raw 4:2:2 and then compress to 4:2:0 on the Canon.

Vertical pixel shift on the other hand kills any hope of a true 4:2:2. On the HVX200 the raw image going to the DSP has an odd form of 4:2:0 and then comprsses to 4:2:2.

On a side note however I'm sure the dvcpro50 mode on the HVX200 does give you pretty close to a 4:2:2 since the chroma shifted 1920x1080 is scaled back down to 720x480.

I really do think Panasonic would have been better off going with a 960x720 CCD block. At least then they could claim a true 4:2:2 in 720p mode.

I'm not saying the HVX200 is a bad camera and doesn't have a good image but it is clearly not capable of 4:2:2 like many have hoped.

John Jay · February 25th, 2006, 01:23 PM

Regardless of the sample size it appears from tests I did here

http://www.dvinfo.net/conf/showthread.php?t=60877

that the Canon has more colour resolution than the Panasonic even though its 4:2:0 versus 4:2:2, admittedly I was working with jpegs - but still - like for like...

Earl Thurston · February 25th, 2006, 10:17 PM

Quote:

Originally Posted by Giroud Francois

So we enter in a new bad era for video camera , virtual pixel.

This isn't new at all. I've used a GL1 for the past five years and both it and the XL1 used pixel shift to generate a full 720 x 480 image from 280K pixel CCDs. And both camera's images have looked great.

Chris Hurd · February 25th, 2006, 10:29 PM

Quote:

Originally Posted by Giroud Francois

now camera can advertise any resolution (or pixel count) regardless to the real one on the CCD. very sad in fact....

Not sad at all. This would be bad news only if Pixel Shift was a useless gimmick... but instead Pixel Shift is very real, very useful, and very much a good thing. Pixel Shift is something you want. It's been around for a very long time, and the majority of three-chip video cameras are using it. Pixel Shift provides more sampling points per pixel and actually does increase resolution. What counts is not the actual resolution of the CCD. What counts is the resolution that the DSP provides to the recording mechanism. Remember it was Pixel Shift in both axes that allowed the Canon XL1 to produce very good DV despite having only 250,000 effective pixels per CCD.

Ash Greyson · February 26th, 2006, 12:52 AM

I agree Chris but I do think there should be an asterisk next to specs that explain the details. I mean Panny has touted that the CCDs were native 1080p, if not directly, indirectly, same with the 4:2:2 color space.

ash =o)

Chris Hurd · February 26th, 2006, 01:27 AM

Or better yet (in my opinion), a paragraph or two in the next generation of HVX200 pre-sales marketing literature entitled "What is Pixel Shift and why is it so important to this camera."

February 25th, 2006, 01:01 AM	#1
Jaser Stockert Regular Crew Join Date: Jan 2004 Location: California Posts: 147	hvx200 pixel count revealed http://www.dvxuser.com/V6/showthread.php?t=47570 looks like steve mullen nailed it!

February 25th, 2006, 12:11 PM	#7
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Pixel Shift in the XL H1 is indeed horizontal axis only. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

February 25th, 2006, 12:53 PM	#9
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	Barlow, not sure I'm exactly answering your question and I'm no tech expert, so those who are may want to amplify/correct, but I'll take a stab at it... Just as with the Panasonic, the format of the HD-SDI out (4:2:2) has nothing to do with how the signal was obtained within the CCD block or the original detail before processing. It is simply a particular kind of output; the luma and chroma detail within the CCD block get processed, and output in either SDI or HDV, or both. Same with HDV...the 4:2:0 is simply the HDV spec'ed output of the processed signal from the CCD block. So the chroma DETAIL might not quite as sharp as it would be from a true 1920x1080 4:2:2 or 4:4:4 source, but the signal is still 1920x1080 at 4:2:2 __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

February 25th, 2006, 01:23 PM	#11
John Jay Major Player Join Date: Sep 2002 Location: US & THEM Posts: 827	Regardless of the sample size it appears from tests I did here http://www.dvinfo.net/conf/showthread.php?t=60877 that the Canon has more colour resolution than the Panasonic even though its 4:2:0 versus 4:2:2, admittedly I was working with jpegs - but still - like for like... __________________ John Jay Beware *PLUGGER-BYTES*

February 26th, 2006, 01:27 AM	#15
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Or better yet (in my opinion), a paragraph or two in the next generation of HVX200 pre-sales marketing literature entitled "What is Pixel Shift and why is it so important to this camera." __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

February 25th, 2006, 03:38 AM	#2
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Yeah, you gotta hand it to Steve, he figured it out down to the pixel. Well done, Mr. Mullen.

February 25th, 2006, 08:07 AM	#3
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	The interesting thing about using pixel shift is that there is no way that the HD video could have 4:2:2 color. Even Juan said from Andromeda that he never claimed his device gave 4:4:4 in HD modes because the color channels alternate every other pixel. He wasn't sure really what to call it but it is more like a 4:2:? that might actually be closer to a 4:2:0 but without the skipping of the every other line lick in mpeg2 4:2:0. Youwould have true blocks of color that are 2x2 pixels in size but not 2x1 pixels like in a true 4:2:2. Yes the format records 4:2:2 but the source is not 4:2:2. Yes it is still slightly better than HDV but not like compaing 4:2:0 to 4:2:2. If the 4:2:2 was the main reason for somebody getting the camera they may have to think about this a little bit more. With the HVX200 even if you went analog uncompressed the HD is still pixel shifted to give this chroma reduction. With any other HDV camera and analog uncompressed at least you are getting a true 4:2:2.

February 25th, 2006, 10:38 AM	#5
Jarred Land DVX User Join Date: May 2003 Location: Vancouver Posts: 281	yeah.. a few people got it.. my favorite was the guys that took it apart and used a microscope to count the pixels. :)

February 25th, 2006, 12:44 PM	#8
Giroud Francois Inner Circle Join Date: Feb 2004 Location: switzerland Posts: 2,133	So we enter in a new bad era for video camera , virtual pixel. now camera can advertise any resolution (or pixel count) regardless to the real one on the CCD. very sad in fact....

February 25th, 2006, 12:55 PM	#10
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	yes horizontal is fine for 4:2:2 since you take only every other horizontal chroma sample. You end up with a raw 4:2:2 and then compress to 4:2:0 on the Canon. Vertical pixel shift on the other hand kills any hope of a true 4:2:2. On the HVX200 the raw image going to the DSP has an odd form of 4:2:0 and then comprsses to 4:2:2. On a side note however I'm sure the dvcpro50 mode on the HVX200 does give you pretty close to a 4:2:2 since the chroma shifted 1920x1080 is scaled back down to 720x480. I really do think Panasonic would have been better off going with a 960x720 CCD block. At least then they could claim a true 4:2:2 in 720p mode. I'm not saying the HVX200 is a bad camera and doesn't have a good image but it is clearly not capable of 4:2:2 like many have hoped.

February 26th, 2006, 12:52 AM	#14
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	I agree Chris but I do think there should be an asterisk next to specs that explain the details. I mean Panny has touted that the CCDs were native 1080p, if not directly, indirectly, same with the 4:2:2 color space. ash =o)