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Uprez dvcpro-HD
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[Herb Sevush] “Up-Rez means going from standard def to ANY HD format”
For few years I’ve been reading (and using) the term Uprez whenever the people try to make a picture bigger, what ever the original size and whatever the target size.
However if you show me a serious document stating what you say i will happily accept it.[Herb Sevush] ” the differences between the various HD formats is insignificant. for instance I can make the case that going from 720P60 to 1080i invovlves no expansion of data whatsoever, just a change between temporal and physical dimensions”
Insignificant to make 1920×1080 pixels from 1280×720 pixels?
Insignificant to make 1280×720 Square pixels from 960×720 HD pixels?
After the “cross conversion” not a single pixel of your picture is the same than the original.
If those are “insignificant’ changes please tell me what do you consider “significant” changes.
rafael -
For few years I’ve been reading (and using) the term Uprez whenever the people try to make a picture bigger, what ever the original size and whatever the target size. However if you show me a serious document stating what you say i will happily accept it.
I have no serious documents to offer, just logic.
Insignificant to make 1920×1080 pixels from 1280×720 pixels?
Insignificant to make 1280×720 Square pixels from 960×720 HD pixels?Apparently your notions of size is constrained to the individual frame, which would make sense if we were talking still photography. But we are not, we are talking about motion pictures, and here temporal considerations also apply.
So yes, the differences are insignificant compared to going from 480X720 interlaced to 1280×720 progressive. The reason 720 is comparable to 1080 is the progressive frame rate. If you actually count pixels per second, 1080p24 has 1920x1080x24 (49,766,400 pps) 720P60 has 1280*720*60 (55,296,000 pps) which comes to around a 10% difference, with what you consider the smaller size having the larger amount of information. If you were using 1080i30 it would be approximately 62,000,000 pps still about a 10% difference, albeit the other way. However standard def has 480*720*30 (10,368,000 pps) which is aprox. an 80% difference from 720P. So I stand by my statement that the difference between the various HD formats is “insignificant COMPARED to the difference between SD and HD.”
The logic in using one term “up rez” to indicate the always huge and one way change in data and the term “cross convert” to indicate a much smaller and often more complicated change in data size makes a lot of practical sense.
Herb Sevush
Zebra Productions -
[Rafael Amador] “Todays is the other way round and manufacturers use terms like “cross conversion” that is absolutely meaningless but it sound very well in a brochure. “
No, not really. It’s not a marketing term. It’s an actual term that’s been in use before I ever saw it in any “marketing brochure.”
To go from Standard Def to High Def is an Up-convert. If you want to call it an “up-rez” that’s fine.
To go from High Def to Standard Def is a Down-Convert. If you want to call that a “down-rez” that’s fine.
To go from 720 to 1080 is a Cross Convert as you’re staying in HD, just converting from one form of HD to another.
To go from 1080i to 720 is a Cross Convert as you’re staying in HD. You would never call 1080 to 720 a down-convert because you’re not losing any quality, you’re staying in HD.
Use the terms as you wish Rafael, but don’t call them marketing hype. I’m not sure why anyone would bother to make that up for marketing anyway, your argument makes absolutely no sense to me.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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You would not call an NTSC to PAL conversion an Uprez simply because the frame size is larger, would you?
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[John Pale] “You would not call an NTSC to PAL conversion an Uprez simply because the frame size is larger, would you?”
John,
Thats call Standard Conversion since more than 60 years ago.
rafael -
I don’t know who first coined the terms up, down, and cross conversion but like Walter I’ve always seen Up/Down refer to going between SD & HD and Cross for going between HD formats. At least in the US those seem to be the commonly used terms in my experience.
-A
3.2GHz 8-core, FCP 6.0.4, 10.5.5
Blackmagic Multibridge Eclipse (6.8.1) -
There does seem to be some interest in perpetuating the misconception that 1080 is bigger, therefore better. How many times have I heard people speak of 1080i as “true HD”? The formats are different, and each has it’s strengths. To this day, find myself explaining the differences to professionals all the time.
We need more clarity, not more confusion – “cross convert” seems very clear to me.
Bobhttp://www.lightstreamassociates.com
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Ikegami HLDV7 – PVW EX-1 -
I too, use the terms up, down and cross. But I can certainly see Rafael’s point.
I’ll use my home TV for example. I have cheap vizio 37″ 720 native TV. When I watch SD out of my Charter cable box it looks OK. When I watch HD it looks very good. Now on a cheap 1080 TV the SD channels are pretty much unwatchable while the HD still looks very good.
Also noting that if you went from HD to 2K you’d call that an upconvert even though that’s less of of jump from 720 to 1080 which is considered a cross conversion.
Like I said at the start, I know and use the proper terms, however Rafael’s point of view makes more sense to me.
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[Rafael Amador] “Funny, in Laos we call that Upscaling, upsizing or so.
This of cross-conversion sounds to pure marketing. “Actually not.
Cross Conversion is a SMPTE term for the conversion between the existing HD formatsFirst off 960×720 is a Data format that is not for broadcast
– SMPTE video is always 1280×720 or 1920 x 1080.1080 is always played back as interlace in BROADCAST. That means at any point in time only 540 lines are being displayed.
720 on the other hand is always progressive – the frame size is 1280 x720 and 720 lines are always being played back.
Based on this alone the 720 <> 1080 conversion can be considered a cross conversion since technically in a field x frame conversion 720 appears to be the equal to 1080.
I am not going to get into pixel counts or LPI since those are dependent on too many other factors like sensor size or actual resolution, P vs I, and lastly – the quality of the lens necessary to make that a truly correct and factual statement there are a number of other factors to consider.
gary adcock
Studio37
HD & Film Consultation
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https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php -
Agreed. Its something different than an uprez. My point is that so is cross-conversion.
In both instances you are changing the video considerably, but it is not an up-rez simply because the frame size has a greater number of pixels in it.
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