Template talk:TV resolution

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hi, what do you think, if the template for tv resolution looks like this de:Vorlage:Arbeitsgemeinschaft der öffentlich-rechtlichen Rundfunkanstalten der Bundesrepublik Deutschland (taken from this template: de:Vorlage:Navigationsleiste_mit_Bild)? so the image of the different resolutions is visable has a link to the bigger version, and the link beneath can be deleted)

Please fix it to make it look better - I just tried updating it from how I found it. Although, please leave it in english :-). -Mydotnet 04:01, Jun 14, 2005 (UTC)

hi, it is just an exampple, how I would like to see the template for tv resolution in the English wikipedia. It is not possible to take the template from the German version an putting it into the English article directly. It is just for a comparision of the tags and sourcecodes, nothing more. I would do it myself, but I am a bad coder :D, greets, --Andreas -horn- Hornig 17:33, 14 Jun 2005 (UTC)

Contents 1 Revised 2 Frame rates & 1080p 3 Pulled frame rates 4 Concerns about the accuracy of the image 5 Revert 6 Suggestion for a different representation of resolution 7 info box or navigation box?

[edit] Revised

I fixed some errors, particularly 720i, and resolutions being devalued due to low frame rate. It might be better to drop frame rates entirely. 1080i and 1080p don't belong in the same class since there is quite a difference, (even when 1080i signals are deinterlaced.) but I wasn't sure what to call 1080p, so I ended up with "HDTV+". I'd prefer some title connecting it with 35mm film quality. Algr 05:48, 2 May 2006 (UTC)

What is with this unexplained revert? If you are going to remove someone else's work, at least explain what you didn't like about it. User 201.58.102.165 restored all sorts of errors that I discussed above. Algr 16:01, 9 May 2006 (UTC)

[edit] Frame rates & 1080p

Thanks for the formatting fix. (How do you move columns like that?) However you have reintroduced the problem of resolutions being devalued due to low frame rate. An HDTV signal remains HD even if it is showing a still image, (0 hz) so 480p doesn't drop to SDTV simply because it is 24 hz and not 60 hz. Also, there is a huge difference between broadcastable 1080i, and the 1080p you see in the movies. (1080i broadcasts have reduced horizional resolution, obvious compression artifacts, and the losses due to interlace.) So these shouldn't be lumped together into the same category. Algr 16:47, 15 May 2006 (UTC)

I guess you want to look into the rowspan and colspan attributes or at table markup in general.

I tried to stay consistent with the linked (and transcluding) articles, e.g. EDTV, which is the loosest defined of the terms, though. Furthermore 480i60, 576i50, 1080i60, 1080i50 in film mode, alias progressive with segmented frames, are no different (except for some compression overhead) than 480p30/p24, 576p25, 1080p30/p24 and 1080p25 respectively, if deinterlaced correctly. Likewise a movie in 720p60 on TV doesn’t look any better than with 720p24, because the source frame rate is just 24 Hz and the rest depends on the display refresh rate. It’s true AFAIK that 1080i is sometimes—maybe even often—broadcasted with only 1440 pixels per line, despite having a 16:9 display aspect ratio, but this also happens with lower vertical resolutions—that’s the one that is much more important to the human eye. Likewise compression artefacts are a matter of source quality and form, bandwidth, compressor and compression method, all of which also applies to lower resolutions in DTV, too. I would expect a digital cinema with a reasonable screen size (and the production side of course) to use much more than 1920 × 1080 pixels—those (upcoming) resolutions are called “2K” and “4K” in the industry AFAIK.

The main fault of this template, IMO, is the ugly image it uses (and which I created). Christoph Päper 14:32, 16 May 2006 (UTC)

Progressive with segmented frames would still be progressive, not interlaced.

that’s the one that is much more important to the human eye. - I'm sure this is wrong. Horizontal and vertical resolution are equally important, and while I've seen this statement on wikipedia before, I've never seen a source for it. Remember that when connected to a standard 480i TV set, both VHS and DVD have the identical vertical resolution - only horizontal resolution improves. And yet the difference is obvious. The reason that you don't see any difference between 1440 and 1920 is that few HD sets are really that sharp yet.

The standard for projection is 2k, which equals 1080p. There is one near my house and even when cropped for widescreen (810x1920) it is as sharp as any 35mm I have ever seen. 4k is for production only, and is only obviously better when viewed in IMAX.Algr 22:09, 16 May 2006 (UTC)

Psf is an interlaced signal that should be displayed progressively. Usually the discussion is about transmission (or storage) formats. (However (in)sane that may be.)

The mere fact that despite the aspect ratio horizontal resolution may actually even be lower than the vertical might tell you which one is (considered) more important. The visual acuity of the human eye is similar (~1°) in both directions, though. Anyway, although I’ve take ergonomics classes in the past, I’m by no means an expert in this field.

You can’t fairly compare analog and digital images like this—even VCD often looks better than VHS. Christoph Päper 11:59, 17 May 2006 (UTC)

It is not a question of what is important, but what is feasible. VHS was limited to 240 lines because doing better in 1974 would have made the deck too expensive to succeed as a consumer device, and TV sets back then couldn't display the extra detail anyway. The situation now with HDV is exactly the same. 1440 isn't as good as 1920, but it is still an outstanding image that will get people to buy new stuff.Algr 17:55, 17 May 2006 (UTC)

Psf is a sort of half-empty vrs half-full distinction. The image is exposed progressively, and then the data is arranged so that it can be read out in an interlaced order. I would consider this progressive since it is required that the two fields can be reassembled into a true progressive image without any fancy motion prediction or guesswork. I understood that PsF was only for formats like DV that weren't originally designed for progressive signals. I wasn't aware that PsF is broadcast legal - I really don't see the point of doing this instead of normal 24p. Algr 18:15, 17 May 2006 (UTC)

[edit] Pulled frame rates

I pulled the frame rates from the template. As it was, you'd already have to understand it to figure out what frame rate was going where. And in any case, frame rate is irrelevant to resolution. A 1080p still image is still HDTV. Algr 05:42, 19 June 2006 (UTC)

Okay Crissov, you put it back, but it is still confusing and wrong. Is it really permissible to broadcast 1080/50i in America, or 60i in Europe? What article depends on this template for frame rate info? Algr 20:38, 19 June 2006 (UTC)

ATSC and DVB are both able to handle all these formats. The European (EICTA) HD ready label requires displays to support both, but broadcasters chose 50 Hz. Look at any of the detail articles like 480i, 576i, 720p and 1080i—I think the template fits in nicely, although I'm not that happy with the illustration still. They don't depend on the information on rates, though, but I never said that either. Christoph Päper 12:00, 20 June 2006 (UTC)

I think you are trying to lump too much data into one table and ending up with something that just doesn't work. Now the table includes 576/60p and 480/50p, which no one has ever wanted. (Readers are never going to guess what those semicolons are supposed to mean. ) Frame rates have nothing to do with resolution, they should have their own table. HDTV is inherently complex, so we need to work hard to keep things clear. BTW, what don't you like about the illustration? Algr 15:45, 21 June 2006 (UTC)

Well, the semicolons are just there to save us from two more rows for PAL/NTSC distinction; if you think it would be clearer otherwise, we could do that of course. The table always included the EDTV definitions, although it has differed as to what was considered enhanced (sometimes progressive SDTV, sometimes 720p with less than 50 Hz). This template is—or at least was—intended to be kind of a navigation template, but organised and with an illustrative picture. It’s hard to visualize the different (digital) TV formats, when one wants to incorporate such things as interlaced vs. progressive scan, transmitted vs. displayed resolution and aspect ratio, 4:3 vs. 16:9, analog vs. digital, PAL/SECAM and NTSC, frame/field rates—the current image does a mediocre job at this. 3D diagrams, which would probably be required to cover all these points, can OTOH only communicate things well when one or two formats get one diagram and not all are lumped together into one.

1080i60 (My own try isn’t rendered as well yet.)

The template is crowded, though. Christoph Päper 09:11, 22 June 2006 (UTC)

[edit] Concerns about the accuracy of the image

Much discussion is taking place here... Image_talk:Resolution_chart.svg

Tvaughan1 20:38, 5 October 2006 (UTC)

[edit] Revert

Sorry about the reversion, but that version included numbers that do not exist in any real standard. 480p and 576p do not use square pixels, so multiplying by the aspect ratio does not get you the correct horizontal pixel count. The correct pixel count is 720 horizontal for both wide and 4:3 versions of both PAL and NTSC DV. (The US standard DTV permits 640x480 as well, but I don't know if anyone uses it - no videotape standard permits 640x480.) Algr 06:55, 6 October 2006 (UTC)

Moved by Algr:

Revert. 852 or 768 horizontal are not part of any standard. (non-square pixels)

First of all, 852x480 is the resolution of the 480p EDTV standard with square pixels. Just because DVDs use non-square pixels to achieve 852x480 and claim to be 480p, it doesn't change the EDTV standard (See de facto standard). As for 768, that is one of the PAL standards (the specifics of which I am not as familiar with, so I may have incorrectly assumed square pixels where they were not, in which case that box can be removed or resized). Finally, I don't see why you would do a hard revert to the older, even more incorrect graphic instead of just downloading and editing the new one. Noclip 17:53, 6 October 2006 (UTC)

Noclip, your image, unlike mine, claims to be an exact pixel count. But no camera or VTR records exactly 852 or 768 pixels horizontally. (Only a few plasma displays ever used 856x480, and they are no longer in stores.) 480i or 480p pixels are NEVER square unless it is 640x480, 4:3 aspect ratio. My image, by comparison, measures resolution in progressive equivalent pixels - In other words, how many progressive pixels would you need to achieve the same detail. And I have offered three sources that say that a detail loss of about 3:2 for interlace is accurate: [1], [2], [3]. Because of non-square pixels, getting both the pixel count and aspect ratio right at the same time is mathematically imposible. My chart acknowledges this in the text, and chooses to display resolution at the expense of aspect ratio. Algr 21:41, 6 October 2006 (UTC)

You're not understanding what I'm saying. "True" 480p is 852 by 480 pixels square. I don't see you claiming that 1080i is really 1440x1080 because that's the resolution HDV and broadcast HD use with a 1.33 PAR, and saying 480p is 720x480 just because DVDs achieve that resolution with a 1.18 PAR is the exact same thing. Just because the most common implementation is 720x480 with non-square pixels, it doesn't mean 480p is. I changed 1080i to 1920x1080 because no format standard dictates a specific pixel aspect ratio that has to be used, they only dictate the final resolution that is to be achieved, and if 1080i is to be displayed as 1920x1080, then 480p must be displayed as 852x480. You're free to add "DVD" to the DV NTSC box, but that doesn't change the fact that true 480p is 852x480. As for PAL, as I said I'm not very familiar with it and the true pixel count may well be different in which case you are invited to download and edit the image to reflect the correct size.Noclip 23:28, 6 October 2006 (UTC)

Noclip - While we are getting somewhere improving the accuracy of this image, Algr may have a point here. I'm not sure where you are getting a resolution of from. Although there are a few different digital TV specifications that were created and implemented over the years, the latest and greatest is CCIR-601 (now known as ITU.R BT-601), which has a pixel resolution of 720 x 483. This is also defined by SMPTE 293M. Later efforts were made to create a Common Image Format (CIF), which has a 858 pixels per line, and 525 lines per frame. However 138 pixels are inactive because they occur during the horizontal blanking interval, and 45 lines are inactive because they occur during the vertical blanking interval... meaning that the active picture area has a pixel resolution of 720 x 480. This appears to be the generally accepted common implementation of 480i. 480p59.94 has twice the data rate of 480i, but it is defined by the same specifications, and it has the same active picture area. PAL has 576 x 720. (768x568 when square sampling is used... but this appears to be less standard). Tvaughan1 19:22, 7 October 2006 (UTC)

480p is 852x480 (really 853 but nobody likes odd numbers). 480i is 720x480 or 640x480. Noclip 20:40, 7 October 2006 (UTC)

Noclip - I have searched all of my resources, and I find nothing that matches your information. Do you have a reference for this? I can see that 852x480 is a common resolution for television displays... but this is not a signal specification. Unfortunately, the SMPTE specs aren't freely available... but everything that I have found that refers to CCIR 601 and SMPTE 293M shows that 480i and 480p have 720 x 483 (or 480) active pixels. They have more pixels per frame, but the rest of the pixels are in the blanking interval. Please cite a source for your understanding that the native signal resolution of 480p is 852x480. Tvaughan1 23:06, 7 October 2006 (UTC)

Although this document is about using AVC, it refers to the existing standards... [4]. See page 4. Tvaughan1 23:06, 7 October 2006 (UTC)

Isn't VBI (and HBI) something totally irrelevant to digital video? It's pointless to compare analog SDTV to digital HDTV (or vice versa).

Digital Video standards incorporate a Vertical Blanking Interval (VBI) and Horizontal Blanking Interval (HBI) for timing purposes. The digital versions of what is commonly known as "NTSC" and "PAL" (which aren't scanning standards, they are color standards) have scanning and timing structures identical to their analog counterparts. Tvaughan1 04:41, 8 October 2006 (UTC)

[edit] Suggestion for a different representation of resolution

To visualise a comparison of video resolutions, you could for instance use a checkboard pattern with (macroblock-like) segments sized 8 × 8 or 16 × 16 pixels in the stored / transmitted format (like 720 × 576 with 6480 or 1620 fields), which is then stretched (or maybe cropped) to the displayed resolution (like 768 × 576 or 960 × 540). You could use any other image instead of course, but I think a simple square pattern was an adequate choice. Visualising the effects of (de)interlacing isn't easy in a still image (and it is unnecessary for correctly handled film mode of course); any try will never be accurate nor accepted by everyone. What you can try to show are the methods and (side) effects of different variants of deinterlacing. The required bandwidth can be quite well shown with 3D diagrams (width, height, frequency). More or less common (digital) horizontal resolutions accompanying 576 lines vertically (and 50 Hz) are 352, 480, 544, 704, 720, with either 4:3 or 16:9 dispaly aspect ratio, by the way. Someone should list all common TV display resolutions, old and new (e.g. 640 × 480 and 1366 × 768). Christoph Päper 21:44, 7 October 2006 (UTC)

So basically you are suggesting putting a grid pattern inside the blocks that show what the pixel aspect ratio is? That sounds like a good idea. Although with some of the blocks (like PAL) mostly covered by others, it could be tricky to make it clear. Algr 18:09, 8 October 2006 (UTC)

I can't picture exactly what you are describing... but a grid / checkerboard pattern could be confusing. In my opinion, the main benefit of higher resolution is that it enables a wider viewing angle, allowing for larger displays. Standard definition television is best viewed from a distance equal to 6 picture heights. HDTV is best viewed from a distance of about 3 picture heights. This means that the screen occupies a wider angle, allowing the viewer to be more immersed in the video program. It also means that you can purchase a bigger screen without seeing the scan lines, pixels, or other artifacts. The current resolution chart shows the relative "size" of the different display resolutions, and this is proportional to the viewing angle, and inversely proportional to the viewing distance for a screen with a given height. As we have been discussing, there are many "other factors" that can effect perceived resolution or picture quality... but these other factors should probably be discussed in separate articles or sections, so as not to confuse the basic point... digital video specifications start with a basic native resolution, and things can only get worse from this point. In other words, if the signal pixel resolution is 1920 x 1080, you will never get 4K pixel resolution... the best you will get is 1920 x 1080. Tvaughan1 19:47, 8 October 2006 (UTC)

And I'm maintaining that you are focusing on the wrong "Basic point" by focusing exclusively on pixel count. There are now many DVD players that output 1080i signals via up-conversion. We know that this can't look like real HDTV, but there really are 1080x1920 pixels coming out of this player, and people will wonder what they need Blue Ray for if this box can get 1080i out of their existing collection. If the article features "1080 pixels" prominently and buries details about quality loss and interpolation in the fine print, then you are adding to the confusion. Algr 20:42, 8 October 2006 (UTC)

I'm not focusing exclusively on pixel count... but pixel count is the most basic, fundamental quantity for the spatial resolution of a digital television signal. Pixel count is the video (or still image) equivalent of bit depth (bits/sample) for audio signals (and field rate is the equivalent of sample rate). The visual acuity of a normal person is about 1/60 of a degree. When you are looking at a video monitor, you can calculate the angle is within the two imaginary lines that go from your eye to the left and right (or top and bottom) edges of the monitor. To avoid visible resolution artifacts (pixelation), a video display should have at least 60 pixels per degree with respect to the angle that the display occupies in the viewer's field of view. Obviously the viewed angle of the display depends on the size of the display and the distance of the viewer from the display. For SDTV, the horizontal viewing angle at the optimal distance is about 11 degrees. For 1080i the horizontal viewing angle is tripled to 33 degrees.

Algr - Your example reinforces my point; it doesn't contradict it. The native resolution of an NTSC DVD is 720x480. You can't create more resolution than the native resolution - it can only get worse. As you pointed out, you can't really "up-convert" (the resulting increased bits are known as "empty resolution"). The signal can be resampled to 1920x1080, but the real pixel resolution of the up-sampled signal is still 720x480. If it is done properly, an up-sampled signal won't lose any quality (but it won't gain any). A signal chain is only as strong as its weakest link. Signal quality can never be "improved" after capture (although you can make some improvement to the perceived picture, such as color, brightness, contrast). Generally speaking, quality is either maintained or it is degraded by the components in the signal chain following capture (encoding, storage, editing, transmission, receiving / decoding, display... not necessarily in that order, or including all of these). In any case, the spatial resolution of a video signal is not the be-all and end-all signal, but it is an important measure that should be quantified. Sure, it is possible to have a 720x480 video signal displayed that actually looks better than a particular 1920x1080 signal / display... if one is done well and the other is done poorly. But all things being equal, more resolution is better. It is not possible to have a 720x480 signal match a well done 1920x1080 signal. Why is more resolution better... what is the important thing about resolution? It allows you to view a greater angle... a "wider and taller" view of the scene being shot by the camera... without noticing pixelation (sampling error). This stuff is chapter 1 of "Digital Video and HDTV Algorithms and Interfaces, Charles Poynton... and several other excellent books on video... it is absolutely fundamental.

Other articles that discuss some of the issues that can affect image quality could be helpful, and could be referenced from many of the video articles that reference the TV resolution template. Tvaughan1 22:39, 8 October 2006 (UTC)

[edit] info box or navigation box?

hi ho everyone, for me it is not clear which purpose this template has. is it an info box explaing the techniques or a navigation box for linking several articles with it? as far as i know the intention of the initial template was for navigation, but now it seems that this changes to an infobox. please do not make the mistake to use a navi box for explaing, please seperate this! as a user i do not want to understand the displayed facts when just getting to another article. if you want to create an infobox for several articles then you should consider to explain more by using old fashion texts in it. e.g. i do not know if you guys mean by "1:1 PAR", i think it ist 1:1 pixel ascpect ratio, but a newbie does not know that! this should be clearly written and written as an wikilink. whether you want to keep it clear and simple as a navi box should be to get from here to there fastly or you should use more text and more "space". the current middle way of both is not a good compromise. that as an first reaction i will now read the rest of your postings. please give me some time ;). greets, --Andreas -horn- Hornig 14:18, 10 October 2006 (UTC)