A Salute To The Humble Direct View Tube TV. - Page 4 - AVS Forum
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post #91 of 261 Old 11-10-2004, 07:41 AM
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Originally posted by Budget_HT
I would like to offer another perspective on CRT construction and its impact on viewable resolution. I am by NO means an expert in this area, but I do believe that I understand and have personally seen the differences that I describe below.

I am talking about the difference between a direct-view color CRT and a front- or rear-projection combo of three monochrome CRTs--one for each primary color.

The direct-view CRT definitely has a physical resolution limit based on the size and placement of individual phosphors and the triples or stripes of the three primary colors that make up a point on the screen capable of displaying a full range of colors.

A single color/monochrome CRT, in contrast, has a "continuous" phosphor coating of a single "color." The small size of the monochrome CRT and the physical properties of the phosphor coating together influence the maximum available resolution, along with the size of the spot delivered by the scanning electron beam.

Aiming the ouptuts of the three monochrome CRTs in perfect alignment (convergence) on the shared projection screen allows a single point of light to vary in color. Theorectically, these points of light could be small enough to match the actual pixel size needed to display the picture at its delivered resolution. If the electronics and CRTs could handle all of the ATSC-defined picture sizes and "resolutions" (by varying beam sizes and scanning rates accordingly), then this type of display device would not be "fixed pixel" at all. The pixel size would vary to match the delivered content. Of course, reality places several limits physically and electronically that reduce the flexibility of the 3-monochrome-CRT effective "resolution."

The scanning rates and beam sizes are issues for both the direct-view color CRTs and the monochrome CRTs. Small-screen direct-view CRTs (e.g., 30" and 34" 16x9 screens) have phosphor stripes or trio sizes that are large enough to significantly reduce the visible "resolution" from the original HDTV signal opportunity. The newer Sony and older RCA fine-pitch CRTS (like the RCA 36" 4x3 and 38" 16x9 tubes, both also used by a few other manufacturers) offer approximately 30% smaller phosphor stripes/trios than the "normal" CRTs of comparable size. These are examples of differences of minimum "pixel" size affecting maximum viewable resolution.

I am not trying to take sides or argue with anyone here. I am just trying to share my understandings. I will gladly accept constructive feedback that corrects or clarifies anything I have presented here.
I see no problems with your logic. And you bring up a point that I dont know the answer to. Does a CRT in a 3-gun array have a shadow mask?

If its doesnt, and the crt can vary beam spot size, I would concur that in a 3-gun array, a CRT could be considered a variable pixel device.

Nice point

ss:)

No shadow mask in front projectors. Since the phosphors are continuous and there is nothing to delineate one pixel(the shadow mask apeartures and the individual phosphor triads do this on a direct view set) from the next, I will agree even without the beam spot size being variable.

To be a fixed pixel device, there has to be a definable number of seperate, unique and individually addressable pixels. I completely concur, that a CRT front projector doesnt fall into that category.

In my defense I wasnt talking about a front projection rig, but I probably used the term CRT above in such a way that doesnt exclude them. They need to be excluded.
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post #92 of 261 Old 11-10-2004, 07:48 AM
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AFAIK, a monocrhome CRT used in a 3-gun array does not have a shadow mask.

I don't know whether, or to what degree, that the beam spot size can vary. I suspect it may vary as a function of brightness, but I don't know whether the maximum beam spot size can vary to accomodate picture size and resolution differences.

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post #93 of 261 Old 11-10-2004, 08:09 AM
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Quote:
Originally posted by Budget_HT
AFAIK, a monocrhome CRT used in a 3-gun array does not have a shadow mask.

I don't know whether, or to what degree, that the beam spot size can vary. I suspect it may vary as a function of brightness, but I don't know whether the maximum beam spot size can vary to accomodate picture size and resolution differences.
Everything in my experience with CRT front projectors suggests the beam spot size is not variable. But you are correct, effective beam spot size does increase with brightness. Because there is nothing to prevent this spill over, the amount of area lit by a more heavily driven gun will light up more of the continuous phosphor. It has been my experience that you try to set the line rate at a point where beam spot size and available phosphor real estate compliment each other perfectly. You can feed it lines well above this but at a compromise in image quality.

ss
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post #94 of 261 Old 11-10-2004, 09:25 AM
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Subysouth,
Could please explain what philips is trying to do with the 26pw6341/37 and the 30in same model, they are widescreen analog aspect ratio 16.9.
I guess it would be alright for watching dvds but how would the analog channels look.
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post #95 of 261 Old 11-10-2004, 09:41 AM
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Originally posted by specgeorge
Subysouth,
Could please explain what philips is trying to do with the 26pw6341/37 and the 30in same model, they are widescreen analog aspect ratio 16.9.
I guess it would be alright for watching dvds but how would the analog channels look.
Building a widescreen tv without HD recognition and scaling electronics to save money I am thinking. It doesnt recognize HD or any digital feed and its scan rate is limited to 480i apparently albeit in a widescreen profile.

They kept the widescreen but stipped out the more common digital electronics.

Should be good for DVDs but I would prefer at least 480p.

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post #96 of 261 Old 11-10-2004, 09:48 AM
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I would imagine the analog channels would look really stretched out and worse than a widescreen hdtv
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post #97 of 261 Old 11-10-2004, 09:55 AM
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Originally posted by specgeorge
I would imagine the analog channels would look really stretched out and worse than a widescreen hdtv
I think it would be very similar to what you would find on any of the other CRT "HDTVs". It could either display 480i with unused bars on each side or stretch the image to fit the screen creating distortion or cut the top and bottom off the image and expand it to fill the screen such that it yields a 16:9 image.

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post #98 of 261 Old 11-10-2004, 12:17 PM
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Originally posted by subysouth
...I wasnt talking about a front projection rig, but I probably used the term CRT above in such a way that doesnt exclude them. They need to be excluded.
Likewise for rear projection CRT-based TVs; same types of CRTs as front projection.

IMHO, my RPTV (HD) provides better visible detail than a comparably sized plasma display, in part because of the individual phosphors for each color on the plasma display versus the "single point" mixed colors on the RPTV display.

That said, there are plenty of other potential issues with the RPTV display, including convergence and linearity problems. These do not exist on non-CRT fixed-pixel displays, but are still issues for direct-view CRTs. The presence or absence of a shadow mask (or the Trinitron equivalent--the name of which I cannot recall right now) has no bearing on linearity. The convergence issues are similar, but not identical.

Bottom line: Your eyes are the best (perhaps the only valid) judge of what looks best to you. We can talk spec's and technology all day, but in the end that discussion boils down to the simple "So what?" question.

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post #99 of 261 Old 11-10-2004, 01:16 PM
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Originally posted by R Harkness
I agree with you: I absolutely can't stand poor scaling. If there is one big thingy I'm allergic to it's digital processing - anything that gives that digitized, blocky or smeary look to the image. I will take analog snow and distortions over digital any day, because at least it looks like it's a human being I'm seeing through the poor signal. Whereas poor scaling or compressed digitization of images make it look like I'm watching synthetic humans. Yuch.

When it comes to scaling regular NTSC LCDs are generally just hideous, especially the flat panels.

Luckily I find my Panasonic 42" ED plasma a stellar performer in the scaling department. Analog NTSC channels look, from my seat, pretty much completely analog - in other words the scaling looks "transparent" or invisible - no added digititis to the image. More like a good CRT image but bigger. So in general I prefer watching TV on my plasma over my Panasonic Tau tube set. A good NTSC feed, especially a digital channel without compression artifacts, can give a window-on-the world vibe. The same goes for it's scaling of DVD, which is among the smoothest I have ever seen from any display type, on to Hi-Def which it scales down shockingly well.

So don't give up hope ;)
Hehe, yeah, but how is it at scaling videogames? (not that I expect you to have tried..) Great scaling processing doesn't mean anything to me if there's a lag in it :D Anyway, I would think that the more pixels there are on a plasma, the better it can potentially be at scaling. Too bad it won't go above the 1080 res because the perfect hd resolution is what most people want in a plasma, which pretty much flushes their potential as an excellent multi-use display down the toilet (imo of course) :/ I'm afraid I'm stuck with the good ol' CRT for that department :( (hopefully not for too long)

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post #100 of 261 Old 11-10-2004, 01:28 PM
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Quote:
Originally posted by Budget_HT
Likewise for rear projection CRT-based TVs; same types of CRTs as front projection.

IMHO, my RPTV (HD) provides better visible detail than a comparably sized plasma display, in part because of the individual phosphors for each color on the plasma display versus the "single point" mixed colors on the RPTV display.

That said, there are plenty of other potential issues with the RPTV display, including convergence and linearity problems. These do not exist on non-CRT fixed-pixel displays, but are still issues for direct-view CRTs. The presence or absence of a shadow mask (or the Trinitron equivalent--the name of which I cannot recall right now) has no bearing on linearity. The convergence issues are similar, but not identical.

Bottom line: Your eyes are the best (perhaps the only valid) judge of what looks best to you. We can talk spec's and technology all day, but in the end that discussion boils down to the simple "So what?" question.
yep no shadow mask in CRT RPTVs, need to change that to a 3-gun array.

The answer to the "So what?" question is to change the way people view direct-view CRTs. If a direct-view CRT was seen as IMO what it is, a fixed-pixel device, by consumers but much more importantly manufacturers, we could dispel a lot of these pointless bait and switch routines on resolution. IMO the best picture you are gonna ever get out of any direct view CRT is a pixel-mapped scaled progessive input direct to the sets exact available phosphor/shadow mask count.

All this talk about these direct view sets doing 1080i etc is just incorrect and not helpful to consumers getting the best picture possible - which is the point of this and any such forum I think. Manufacturers are selling direct-view CRT sets claiming wide ranging resolution potentials that are based in fiction. If they based them in reality, the consumer would have a better picture, even if it wasnt "HD."

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post #101 of 261 Old 11-10-2004, 05:46 PM - Thread Starter
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Quote:
Originally posted by Geise
Hehe, yeah, but how is it at scaling videogames? (not that I expect you to have tried..) Great scaling processing doesn't mean anything to me if there's a lag in it :D Anyway, I would think that the more pixels there are on a plasma, the better it can potentially be at scaling.
Agreed. I can't stand motion artifacts of any type, particularly motion lag.
Fortunately that's not a problem with my plasma. Motion for sports (Hockey, football, soccer, basketball) appears pretty much identical to my CRT tube set - perfectly smooth.

Many people who have plasmas are gamers and report being ecstatic with the eye-popping results. As one new Panasonic plasma owner just wrote in the plasma forum: "To be able to sit in a dark room and play this game on my Panny is amazing - my jaw was literally on the floor. "

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Too bad it won't go above the 1080 res because the perfect hd resolution is what most people want in a plasma, which pretty much flushes their potential as an excellent multi-use display down the toilet (imo of course) :/ I'm afraid I'm stuck with the good ol' CRT for that department :( (hopefully not for too long)
I don't think "most people" care about 1080 res in a plasma - maybe some multi-tasking videophiles. Most people care about the image being a good one and the best plasmas provide a stunning image from DVD, Hi-Def and games.

If you feel you are stuck with CRT so be it. Apparently a lot of people are very happy with plasmas for their needs (web surfing, movies, games).
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post #102 of 261 Old 11-10-2004, 09:17 PM
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Originally posted by Geise
Hehe, yeah, but how is it at scaling videogames? (not that I expect you to have tried..) Great scaling processing doesn't mean anything to me if there's a lag in it :D Anyway, I would think that the more pixels there are on a plasma, the better it can potentially be at scaling. Too bad it won't go above the 1080 res because the perfect hd resolution is what most people want in a plasma, which pretty much flushes their potential as an excellent multi-use display down the toilet (imo of course) :/ I'm afraid I'm stuck with the good ol' CRT for that department :( (hopefully not for too long)
I have found that the biggest problem in scaling is a wide difference in input and output. One of the worst(I have seen worst from cable, but I dont expect much at all from cable) scaled pictures I have ever seen was on a Faroudja NR feeding a 1280x720 display. It was the original release of Top Gun on DVD(non-anamorphic and very low quality transfer to boot.) Being non-anamorphic left only about 720x360 image (some real estate still in letterbox) being displayed on 1280x720 device. Thats 1/4 input vs output and man did it look bad. ANTS(anamorphic high quality transfer) on the same device looked near pristine. GIGO

On your comment above about a plasma exceeding 1080 res, why would you want this? What are you going to try to feed it? How close are you going to sit? And your good ole CRT isnt doing 1080 either, unless its an amazingly expensive good ole CRT front or RPTV.

And again how much resolution you need on display device of x size is interactive with your vision and seating distance. If you need 1080 res, you have got a very large display or you are sitting really close.

ss
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post #103 of 261 Old 11-11-2004, 10:10 AM
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Quote:
Originally posted by R Harkness
[b]Agreed. I can't stand motion artifacts of any type, particularly motion lag.
Fortunately that's not a problem with my plasma. Motion for sports (Hockey, football, soccer, basketball) appears pretty much identical to my CRT tube set - perfectly smooth.

Many people who have plasmas are gamers and report being ecstatic with the eye-popping results. As one new Panasonic plasma owner just wrote in the plasma forum: "To be able to sit in a dark room and play this game on my Panny is amazing - my jaw was literally on the floor. "
Uh, I meant processing lag, as in I press a button on my game controller and it takes up to a second or more for the video on the screen to respond...was that what you were referrring to?

Quote:
On your comment above about a plasma exceeding 1080 res, why would you want this? What are you going to try to feed it? How close are you going to sit? And your good ole CRT isnt doing 1080 either, unless its an amazingly expensive good ole CRT front or RPTV.
With digital displays, it always has to decide "should it be this pixel, that pixel, or both?" when scaling. The more pixels there are to work with, the less of a problem this becomes. A very extreme example of what digital scaling can do to an image is the PSone lcd screen. It causes so much pixelated distortion from processed scaling that many games have menu fonts and other graphics that are nearly illegible, and at most look very different from the way they are supposed to look. Other lcd's I've seen with many more pixels still had this problem, but it wasn't nearly as extreme (but still very unwanted).

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post #104 of 261 Old 11-11-2004, 11:39 AM - Thread Starter
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Quote:
Originally posted by Geise
Uh, I meant processing lag, as in I press a button on my game controller and it takes up to a second or more for the video on the screen to respond...was that what you were referrring to?
No, I was thinking of things like phosphor lag, motion blur/trails etc.
These I do not experience on my plasma. In regards to the processing lag you are talking about, in almost four years on the plasma forum, with people talking about playing games on plasmas, I don't remember anyone issuing such a complaint.


Quote:
With digital displays, it always has to decide "should it be this pixel, that pixel, or both?" when scaling. The more pixels there are to work with, the less of a problem this becomes. A very extreme example of what digital scaling can do to an image is the PSone lcd screen. It causes so much pixelated distortion from processed scaling that many games have menu fonts and other graphics that are nearly illegible, and at most look very different from the way they are supposed to look. Other lcd's I've seen with many more pixels still had this problem, but it wasn't nearly as extreme (but still very unwanted). [/b]
Yes, I understand the desirability of a perfect fit of source to display resolution in avoiding scaling errors. I was merely pointing out that "most" people aren't concerned with such technicalities and are looking for a display that looks great with the sources they'll be viewing.

And many plasmas do an excellent job at scaling. As I said, it's the rare display I've encountered that looks as tight and noise-free with DVDs as my Panasonic plasma. Hi-Def looks as smooth as hi-def on any other display I've seen. Even it's scaling of regular cable is, all things considered, superb.

(Rich remembers title of thread) CRT tube sets are great too!

:)
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post #105 of 261 Old 11-11-2004, 12:44 PM
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Quote:
Originally posted by Geise
With digital displays, it always has to decide "should it be this pixel, that pixel, or both?" when scaling. The more pixels there are to work with, the less of a problem this becomes. A very extreme example of what digital scaling can do to an image is the PSone lcd screen. It causes so much pixelated distortion from processed scaling that many games have menu fonts and other graphics that are nearly illegible, and at most look very different from the way they are supposed to look. Other lcd's I've seen with many more pixels still had this problem, but it wasn't nearly as extreme (but still very unwanted).
I think the PSone example is a problem of a pixel deficient screen being the scaling recipient.

I think I kinda see what you are saying tho. You are referring the the inherent square or rectangular pixel display of most digital devices visible if the display is large enough or the input resolution small enough? Youre thinking the smaller the square the less "square" it will appear at the same distance? That is true but, the one or two pixel choice would only become a two or four pixel choice with more resolution on the display device against constant resolution on the input with scaling. The blocky picture would still be there it would just have more pixels per block. The low input resolution(not enough unique data to lay on the available output pixels) is still the problem. And if you further distance input and output resolution(by increasing display resolution capability) the problem becomes worse.

Your input and output resolution need to match and the size of the display youre viewing it on and needs to be consistant with these resolutions too. Meaning, you dont need 1080p on a 30" TV(unless you are really close) and you dont want/couldnt stomach 480p on a 20' screen. The sweet spot is interactive.

ss
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post #106 of 261 Old 11-11-2004, 03:36 PM
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Quote:
Originally posted by subysouth
[b]I think the PSone example is a problem of a pixel deficient screen being the scaling recipient.
Yes it is, and that's why I said it is an extreme example of what happens with digital scaling. It's like a magnifying glass of the effect :)

Quote:
I kinda see what you are saying tho. You are referring the the inherent square or rectangular pixel display of most digital devices visible if the display is large enough or the input resolution small enough? Youre thinking the smaller the square the less "square" it will appear at the same distance? That is true but, the one or two pixel choice would only become a two or four pixel choice with more resolution on the display device against constant resolution on the input with scaling. The blocky picture would still be there it would just have more pixels per block. The low input resolution(not enough unique data to lay on the available output pixels) is still the problem. And if you further distance input and output resolution(by increasing display resolution capability) the problem becomes worse.
Here's another extreme example :): Which digital display could more accurately scale the position of the pixels on a 640x480 digital image; a 1600x1200 display or a 16000x12000 display? It's really the same point as the PSone lcd screen, insufficient pixels result in inaccurate pixel positioning. The severity of course is much less on high res displays, but it still exists, and is very visible on several displays. I don't see why the problem would be getting worse...?

The whole point in more resolution is that the pixel position of the video image would not clash as much with the pixels on the display when being scaled. The display would have more pixel position options because there is a denser population of display pixels to use. I can draw a simple diagram in MSpaint illustrating what I mean if I'm not making sense :) What I want in a display is for the pixels of the source video picture to be displayed as accurately as possible, which means it must either be scaled via the relatively accurate means of a crt, or I'd have to own a different digital display for each different resolution of my various video content :D

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post #107 of 261 Old 11-11-2004, 07:49 PM
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I think all scaling should be against the law and all compression against the law, too. The standard should be 960P.
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post #108 of 261 Old 11-11-2004, 08:05 PM
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Originally posted by Geise
Yes it is, and that's why I said it is an extreme example of what happens with digital scaling. It's like a magnifying glass of the effect :)
Well thats not exactly what you said. There is no input that would have looked good on that screen essentialy because the pixels are too large. It would do graphics mediocrely well, but text is pretty much out of the question. Any output would look like crap on that screen even if it were not scaled at all, there just is not enough pixels in the screen for a decent picture.

For discussions sake, scaling problems like we are discussing should start with an appropriately sized and pixel rich display, a nice looking display on an equal resolution rich input. Meaning we need a good display device so we dont lump its weaknesses on the scaling.

Quote:
Originally posted by Geise
Here's another extreme example :): Which digital display could more accurately scale the position of the pixels on a 640x480 digital image; a 1600x1200 display or a 16000x12000 display? It's really the same point as the PSone lcd screen, insufficient pixels result in inaccurate pixel positioning. The severity of course is much less on high res displays, but it still exists, and is very visible on several displays. I don't see why the problem would be getting worse...?

The whole point in more resolution is that the pixel position of the video image would not clash as much with the pixels on the display when being scaled. The display would have more pixel position options because there is a denser population of display pixels to use. I can draw a simple diagram in MSpaint illustrating what I mean if I'm not making sense :) What I want in a display is for the pixels of the source video picture to be displayed as accurately as possible, which means it must either be scaled via the relatively accurate means of a crt, or I'd have to own a different digital display for each different resolution of my various video content :D
You are kinda getting it but not quite.

Lets use your two examples. Or lemme make ones that are even easier multiples and lets just use one dimension - horizontal. Vertical works the same.

Lets say the horizontal input resolution is 640 and we have two horizontal output resolutions(6400 and 64000) but the screen size is the same - 640" wide. If you scale the 640 input, the image on the screen is identical. In the first case there are 10pixels(1" width on the screen and all identical cause thats all the picture info we have right?) output for each pixel input and in the second 100 pixels(still 1" width on the screen and again all identical) of output for each pixel input. The blocks have more pixels in them, but the pixels are still identical in content and how much screen is taken up by the pixel blocks is the same, so the image is the same.

Can you see that?

Thats why when you blow up low res sources on pixel based display device you get big blocks of the same info. A correctly functioning CRT will have essentially the same effect, the pixel blocks will just have slightly softer edges.

And what I mean by it will be getting worse with more inherent resolution is if the needed resolution(interactive with screen size and viewing distance) is far removed from the input resolution. For example, 480i doesnt look too bad on a "720p" 30" CRT monitor at 8', it however looks horrific on a 90" 1080p device at 8'. When the resolution can actually be displayed, extreme differences in input and output become much more obvious.

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post #109 of 261 Old 11-11-2004, 08:23 PM
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Quote:
Originally posted by Artwood
I think all scaling should be against the law and all compression against the law, too. The standard should be 960P.
I think I know what youre driving at, but why 960(I dont need the p part:p .)

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post #110 of 261 Old 11-12-2004, 02:26 AM
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It's easy to double 480 and get 960--no complicated math for a scaler. How many times do you hear people say how bad SD looks on an HD display at 720p or 1080i. it wopuldn't look as bad at 960--less chance for scaling errors.
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post #111 of 261 Old 11-12-2004, 07:59 AM
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Artwood,

a little off topic but:

Scaling 480p to 960p seems pretty easy to me but I've always been confused about scaling interlaced signals. How does Sony scale 480i to 960i with their DRC interlaced mode?

I thought the logical way would be to first de-interlace 480i to 480p and then scale to 960p and re-interlace to 960i to accomodate the gun frequency of 31.5Khz? But it seems a bit convouted.

If that is not what is done then how do they do it?

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post #112 of 261 Old 11-12-2004, 09:57 AM
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Originally posted by subysouth
Well thats not exactly what you said. There is no input that would have looked good on that screen essentialy because the pixels are too large. It would do graphics mediocrely well, but text is pretty much out of the question. Any output would look like crap on that screen even if it were not scaled at all, there just is not enough pixels in the screen for a decent picture.

For discussions sake, scaling problems like we are discussing should start with an appropriately sized and pixel rich display, a nice looking display on an equal resolution rich input. Meaning we need a good display device so we dont lump its weaknesses on the scaling.

I was referring to digital scaling generally as the way any type of digital display must decide on what to do with pixels that don't match up perfectly with the native resolution. Yes, even that psone screen has a native res you know ;) And the few games that seemed to fit to it looked perfectly represented with zero distortion.



You are kinda getting it but not quite.

Lets use your two examples. Or lemme make ones that are even easier multiples and lets just use one dimension - horizontal. Vertical works the same.

Lets say the horizontal input resolution is 640 and we have two horizontal output resolutions(6400 and 64000) but the screen size is the same - 640" wide. If you scale the 640 input, the image on the screen is identical. In the first case there are 10pixels(1" width on the screen and all identical cause thats all the picture info we have right?) output for each pixel input and in the second 100 pixels(still 1" width on the screen and again all identical) of output for each pixel input. The blocks have more pixels in them, but the pixels are still identical in content and how much screen is taken up by the pixel blocks is the same, so the image is the same.

Can you see that?

Thats why when you blow up low res sources on pixel based display device you get big blocks of the same info. A correctly functioning CRT will have essentially the same effect, the pixel blocks will just have slightly softer edges.

And what I mean by it will be getting worse with more inherent resolution is if the needed resolution(interactive with screen size and viewing distance) is far removed from the input resolution. For example, 480i doesnt look too bad on a "720p" 30" CRT monitor at 8', it however looks horrific on a 90" 1080p device at 8'. When the resolution can actually be displayed, extreme differences in input and output become much more obvious.

ss
What happens if a scaled video pixel is supposed to be displayed directly on one pixel, but also a little bit on the one next to it? You are assuming that the pixels being "blown up" will have the correct number of display pixels representing them. Wouldn't the video pixels only be properly scaled if it is half the resolution of the native res of the display...:confused:

Anyway, just for fun I made a diagram of effects I've actually seen (or think I've seen :D) with 2 different lcd screens when feeding them various video outputs from dvd players and game consoles. I know I'm being a pain, but please be patient with me. I can be very stubborn when learning about complicated things like this :):

http://uploads.savefile.com/redir/16133.gif

(you may need to zoom in with another program to see it clearly, sorry for the size)

1. this represents a lower-than-native resolution checkered image. Each box in the green checkered design is a "pixel" in size (video pixel that is). The grid over top represents the pixels of a digital display. This is showing where the video pixels should be displayed (if the digital display were able to make inner pixel details :D)

2. This is the same image with "digital processing" applied in order for the checkered image to be able to be shown by the pixel grid of the display. The faded pixels represent a pixel on the display that must either choose one color, the other color, or even blend colors. This is probably why many digital displays look "blurry" outside of their native res.

3. This is the exact same checkered image, but with a denser population of digital pixels (on a display of same diagonal screen size as the lower res display). This also represents correct positioning like #1 does (zooming in can help alot :D).

4. This is #3 with "digital processing" applied. I applied the effect using the same principles of #2. It shouldn't be hard to see that the same checkered image is "scaled" quite a bit more accurately by the "denser display".

If any part of that was incorrect, please tell me. This is what I've come to understand about digital scaling. Any added info would be appreciated :) (And very sorrry to the topic poster for hijacking :\\)

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post #113 of 261 Old 11-12-2004, 11:13 AM
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Originally posted by Artwood
The standard should be 960P.
I'm with you, man.
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post #114 of 261 Old 11-12-2004, 01:36 PM
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Quote:
Originally posted by Geise
What happens if a scaled video pixel is supposed to be displayed directly on one pixel, but also a little bit on the one next to it? You are assuming that the pixels being "blown up" will have the correct number of display pixels representing them. Wouldn't the video pixels only be properly scaled if it is half the resolution of the native res of the display...:confused:

Anyway, just for fun I made a diagram of effects I've actually seen (or think I've seen :D) with 2 different lcd screens when feeding them various video outputs from dvd players and game consoles. I know I'm being a pain, but please be patient with me. I can be very stubborn when learning about complicated things like this :):

http://uploads.savefile.com/redir/16133.gif

(you may need to zoom in with another program to see it clearly, sorry for the size)

1. this represents a lower-than-native resolution checkered image. Each box in the green checkered design is a "pixel" in size (video pixel that is). The grid over top represents the pixels of a digital display. This is showing where the video pixels should be displayed (if the digital display were able to make inner pixel details :D)

2. This is the same image with "digital processing" applied in order for the checkered image to be able to be shown by the pixel grid of the display. The faded pixels represent a pixel on the display that must either choose one color, the other color, or even blend colors. This is probably why many digital displays look "blurry" outside of their native res.

3. This is the exact same checkered image, but with a denser population of digital pixels (on a display of same diagonal screen size as the lower res display). This also represents correct positioning like #1 does (zooming in can help alot :D).

4. This is #3 with "digital processing" applied. I applied the effect using the same principles of #2. It shouldn't be hard to see that the same checkered image is "scaled" quite a bit more accurately by the "denser display".

If any part of that was incorrect, please tell me. This is what I've come to understand about digital scaling. Any added info would be appreciated :) (And very sorrry to the topic poster for hijacking :\\)
I see what you are saying now, yes I would agree the questionable pixels would constitute less screen area at a higher resolution. However the question remains as to whether there is enough screen size to warrant that resolution. Meaning would you increase resolution on a screen to reduce visible scaling of an inherently low resolution source? Menaing would you lose detail(assuming you were at the right distance for the sets inherent resolution) to make a poor source look better? Kinda like cutting off you nose to spite your face?

You cant tinker with pixel size without factoring in the interactivity of viewing distance.

If the screen were sufficiently large to require the larger resolution(higher pixel count) the result of Fig 4 to Fig 1 is nearly identical and the differences are not the deal maker or breaker.

Arc of pixel size should never change, if the pixel count is that much lower(Fig 1) you should be moving back to a point where again the net result is very similar.

Does that make sense? The only time the scaling error is going to become visibly worse is when the display is so pixel poor that ANYTHING you play on it will be pixelated(like the PSOne display.) If the pixels are corrrectly sized for that distance, the scaling effect is nearly identical and the larger problem is still the low res input, not how many pixels are laid on it.

Let the scaler makes it choices on based on %fill in both Fig 1 and 4, and then view each final product at an appropriate distance for their pixel size and you'll see that fig 1 is nigh equal in effect to Fig 4. Indiscernable even. The larger pixelation issue will still be the visible problem, not the gradation differences of the pixel sizes themselves.

I'm not saying your point is not well taken, its just not nearly as important as whats driving the real problem.

ss
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post #115 of 261 Old 11-12-2004, 02:52 PM
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For me, it's not a matter of whether or not I will "notice" the scaling, it's that it has to scale that way to begin with that puts me off (I'm a real video purity nut btw :D). Moving back farther from the display is not correcting the scaling problem, it's just ignoring it (and it's not like I sit 2 feet away or anything either). Just not the right way to go about it imo... But anyway, I really just made the diagram to show you (and anybody else) why I hate digital displays for any content outside their native resolution. I really wish someone would at least attempt a new kind of analog technology :( Meanwhile, I generally feel that a good computer CRT monitor represents the best in scalability :) (or even a not so good crt monitor :D)

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post #116 of 261 Old 11-12-2004, 03:12 PM
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Quote:
Originally posted by Geise
For me, it's not a matter of whether or not I will "notice" the scaling, it's that it has to scale that way to begin with that puts me off (I'm a real video purity nut btw :D). Moving back farther from the display is not correcting the scaling problem, it's just ignoring it (and it's not like I sit 2 feet away or anything either). Just not the right way to go about it imo... But anyway, I really just made the diagram to show you (and anybody else) why I hate digital displays for any content outside their native resolution. I really wish someone would at least attempt a new kind of analog technology :( Meanwhile, I generally feel that a good computer CRT monitor represents the best in scalability :) (or even a not so good crt monitor :D)
Its a great diagram, but the pixel size at viewing distance issue trumps the scaling problem. And until there is ONE data rate for HD, DVD, etc. we are gonna have to live with scaling if we want to fully use the displays. You can, however, sacrifice screen real estate and throughput 480p in the center of a 768p device if you want to avoid scaling. Youre losing alot of image though and you cant move closer if you are already at the correct viewing distnce for the pixel size. You just get a smaller but purer picture.

Analog and digital arent the problem either, its info in vs info out.

Picture an old analog CRT set has an actual defined number of usable pixels that the analog gun can address, lets call it 640x480 for arguments sake. No lets put that set in the same postion current HD sets are in vs 480i and feed it a 240x180 res feed. The image is still gonna end up blocky its just gonna have smoother transitions at the edges. Now if the screen is small enough that youre unable to define 640x480 and are only able to define 240x180, youre fine. But if you get close enough to be able to define 640x480, youre back to block city. See how the distance issue trumps all? You cant change how much detail your eyes see.

I again think what is confusing this issue greatly is the fact that CRT manufacturers are telling people their sets are doing wildly different line rates which they actually are not.

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post #117 of 261 Old 11-12-2004, 04:27 PM
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My goal isn't to try to make a low res image look like hi res, it's to display an image, any image, the way it's supposed to look (if an image is low res, then I want to see every gosh darn jaggy exactly as it exists on the medium :)). This means digital scaling, no matter how "unnoticeable", is simply not an option for that purpose. I'm not saying a CRT is perfect either, infact a 1:1 reproduction is always the best choice, but rarely ever possible with the varying video content out there. I'm looking for perfection (or as close as possible), not "whatever looks good". A badly recepted NTSC signal can "look good" from a distance....I want to get it right at the source, not compensate. What would you prefer, move back so as not to notice the flaws, or not have the flaws to begin with? Why do you think audiophiles concern themselves with sound distortion that is out of the human range of hearing? They demand zero distortion (or as close as possible), just as I do with video. Perhaps we just have different priorities with our display preferences?

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post #118 of 261 Old 11-12-2004, 04:59 PM
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Quote:
Originally posted by Geise
My goal isn't to try to make a low res image look like hi res, it's to display an image, any image, the way it's supposed to look (if an image is low res, then I want to see every gosh darn jaggy exactly as it exists on the medium :)). This means digital scaling, no matter how "unnoticeable", is simply not an option for that purpose. I'm not saying a CRT is perfect either, infact a 1:1 reproduction is always the best choice, but rarely ever possible with the varying video content out there. I'm looking for perfection (or as close as possible), not "whatever looks good". A badly recepted NTSC signal can "look good" from a distance....I want to get it right at the source, not compensate. What would you prefer, move back so as not to notice the flaws, or not have the flaws to begin with? Why do you think audiophiles concern themselves with sound distortion that is out of the human range of hearing? They demand zero distortion (or as close as possible), just as I do with video. Perhaps we just have different priorities with our display preferences?
I think so, but its cool.

You can do exactly what I mentioned above to maintain the purity of the signal. Just letterbox it on your available pixels but just realize the only way to do this is change image size. The loss of screen size is significant.

If you have a fictional 1920x1080 70" SED device(yea babee) it will have a .81 pixel size and:

a native 1080i or 1080p image is gonna be 60.9" x 34.3"
a native 720p image will be only 40.8" x 23.0"
a natve 480p(x 853) will be only 27.2" x 15.3 [or 1/5 of the available screen area]

So given those choices of loss of screen size to maintain purity or scaling, I'm gonna go dirty and big. And having seen regular DVD scaled to digital 1366x768 on a 106" screen look relatively awesome, I think its a good tradeoff. Lets not even begin to discuss how good it looks on a well driven and scaled 9" CRT front projector.

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post #119 of 261 Old 11-12-2004, 07:08 PM
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Actually, you just gave me a great (and wallet emptying) idea :D Is that letterboxing function something the tv has to do, or could a seperate device perform the task and input it to the tv digitally? If I could afford a decent sized SED (assuming they are affordable and worthwhile), that just might be the perfect option for me. I could have a pure image for some things, and could go "dirty and big" for other non-critial things ;) I guess in order to get a decent 480p size (20 inches would be minimal) on a 40-50 inch hd display, it couldn't be too high in resolution....(thinking)..

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post #120 of 261 Old 11-12-2004, 07:19 PM
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Quote:
Originally posted by Geise
Actually, you just gave me a great (and wallet emptying) idea :D Is that letterboxing function something the tv has to do, or could a seperate device perform the task and input it to the tv digitally? If I could afford a decent sized SED (assuming they are affordable and worthwhile), that just might be the perfect option for me. I could have a pure image for some things, and could go "dirty and big" for other non-critial things ;) I guess in order to get a decent 480p size (20 inches would be minimal) on a 40-50 inch hd display, it couldn't be too high in resolution....(thinking)..
The only way I am aware of doing it is outside the device via a HTPC or a scaler of high merit(essentially a dedicated HTPC) on a device that allows you direct access to its display grid(CRT computer style monitor or any of the other digital devices with computer input.)

The seds arent even out of the blocks yet, I'm just dreaming. I really like the tech on those and I am hoping they can sort the execution.

Do you want 20" in the vertical or horizontal and how far away do you want to sit, because thats what sets your pixel size?

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