Talk:Pixel/Archive 1

message: and in english this all means?? ÉÍREman 16:16 May 6, 2003 (UTC)
: Indeed. I've had a go at a clearer intro, but I'm not happy with it. I hope someone else can improve it. The problem is that it's very hard to say what a pixel is: screen element; printing; part of a digital image. Though in the last case we're strictly dealing with texels; but only the 3D gaming industry makes that distinction AFAIK -- Tarquin 16:30 May 6, 2003 (UTC)
I'm a historian whole technical skills are such that if I change a light bulb I am likely to black out all of North Dublin, so I am afraid the article went completely over my head, but then anything technical does anyway. But then I suppose people people are are technologically literate might find the stuff I write on historiography or royal naming procedures over their heads too. Each to his or her own! I notice BTW that an earlier version mentioned a mac's 'thousands' and 'millions' in term of screen colours, so I learned something about what that actually means on my eMac. Except that that info was culled from later versions!!! I decided to check just what the hell pixel was because I bought a new digital camera that uses 3.2 million pixels so I was hoping to find out what it was I had bought. The joys of being technologically illiterate! ÉÍREman 19:44 May 6, 2003 (UTC)
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Very nice picture, Tarquin! I'm even willing to overlook the fact that the lines connect the wrong corners. ;) -- John Owens 21:41 May 6, 2003 (UTC)
: dang! I'll fix it later. -- Tarquin (boy am I glad I always keep my layered photoshop documents!)
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I'm a bit put off by: " This can be expressed as a single total,", because it seems to me the single number is a product, not a total... but I can't see how to change it without making it too complicated -- Tarquin 21:48 May 6, 2003 (UTC)
: Is this the bit that now reads "For depths larger than 8 bits, the number is the total of the three RGB ..."? If so, I agree that total is the wrong word, but describing it in a way that a non computer-literate person will immediately grasp is difficult. Perhaps something along the lines of "For depths larger than 8 bits, the bits themselves are divided into three seperate values that describe the intensities of the red, green, and blue components of the desired colour.", since the values are not really either a product or total. Lumpbucket 01:08 August 12, 2003 (BST)
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I added a section on what a digital camera "megapixel" REALLY is, and also added sections for pels and sub-pixels.
On the digicam megapixel subject, I sent an email to the apparent author of http://megamyth.homestead.com, asking him to contribute to the subject. Scott McNay 07:45, 2004 Feb 8 (UTC)
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On another subject, can someone clarify several issues?  I'd like to know:
* whether a "dot pitch" is the same as the pixel size, as loudly implied by this article, and not clarified at all by the dot pitch article?
* how "native resolution" (often seen in relation to LCDs) relates.
* whether "native resolution" applies to CRTs or not (which is implied by this article in the sub-pixel section), at least for horizontal resolution.
* How CRTs and LCDs display different horizontal resolutions when they have embedded color masks, and ditto for vertical resolution for LCDs.
Scott McNay 07:45, 2004 Feb 8 (UTC)
:: Sigh ... I just tried editing the relevant section to put in a couple paragraphs about this... Got an 'edit conflict error'... seems the whole SECTION was deleted wholescale, and I was dumb enough to not copy & paste what I'd written into notepad before whacking "submit". Time to hit the history page and find out WTF is going on, if it's just a vandal or if it's heavy handed editing. I recognise my stuff needs editing, as I'm not a professional writer, but I do know enough of my beans when it comes down to dot pitch vs lcd pixel size, what typical (TCO 99 standards, even!) LCD resolutions are vs size (unlike the unrealistically coarse examples given) to be able to contribute at least the raw materials in some kind of understandable english. Chopping the entire thing seems a little rough, particularly as having scanned this talk page I can't see any suggestions/call for votes/etc on such 82.46.180.56 (talk) 16:09, 2 April 2008 (UTC)
replies: text: Enos Shenk 22:37, 14 Feb 2004 (UTC)
thread_title: old junk not in a section

message: This article contains a large amount of pseudo-erudition caused by layer on layer of pedantic corrections. Some of the pedants knew something about image processing. Unfortunately, most didn't. It now desperately needs editing by actual image-processing experts, followed by extensive copyediting to remove redundancy and simplify flow. -- Karada 20:18, 22 Jun 2005 (UTC)
replies: text: * On a quick read, I found a lot of good stuff here.  I hope we don't get carried away with style and whatever and reduce the meat in the article.  I appreciated what I read.  May give it a critcal read later.
Phil talk 14:47, 14 September 2005 (UTC)
replies: text: I've worked it over some, from a position of knowledge.  I hope my changes don't fall into the overly pendantic category, but that's always a danger when trying to make sloppy stuff be correct. Dicklyon 03:10, 25 May 2006 (UTC)
thread_title:  This article needs a lot of work 

message: which is correct? the article states element, but i have always heard cell - mastodon 22:56, 22 April 2006 (UTC)
replies: text: Most early uses of pixel (1965-1980) specifically said it meant picture element.  The notable exceptions that I am aware of were in publications and patent applications out of Xerox Palo Alto Research Center, 1976 to 1982, which used picture cell.  For example, see US4034343: Optical character recognition system, by Michael Wilmer, filed 1976-10-01.  But since you weren't born yet, maybe that's not where you heard it.  Your pixel historian, Dicklyon 03:07, 25 May 2006 (UTC)
thread_title:  picture element versus picture cell 

message: Who coined the term? Does anyone know? I know a guy who thinks he may have coined it in a naval document in 1973 or so. Jfingers88 01:37, 15 June 2006 (UTC)
replies: text: The earliest known publications of pixel are by Frederic C. Billingsley in 1965; but he did not coin it, nor did Keith McFarland, subcontractor from whom Fred leaned the term.  We don't know who coined it.  See the last external link in the pixel article. Dicklyon 02:06, 15 June 2006 (UTC)
thread_title:  Coinage 

message: What's the story with the new images?  I notice one is alternating black and white pixels, while the other is alternating green and magenta.  Both look gray.  So what does this have to do with subpixels, and why is the first one repeated, and then the pair are shown combined, and there are not words about the figure or its point.  Can someone please explain or fix? Dicklyon 05:20, 1 July 2006 (UTC)
replies: text: The drivers probably have nothing to do with it. The web browser scales the image, and it's usually (at least on Mozilla/Firefox) a quick and simple nearest-neighbour algorithm. Safari and/or Opera might do a higher-quality resampling of the image. So relying on the thumbnail width to force "subpixels" is not going to work. Different web browsers do things differently, it's how the web works. Just what exactly are you trying to show with these images? Imroy 11:16, 2 July 2006 (UTC)
replies: text:  Well, the difference of one pixel changed the appearance of the image (on my (browser) display. On my system, they have one light grey circle (98px) and 4 light grey circles (97px) on dark grey, even though the 'image' is what it is. Just thought this was an universal fenomenon. At least I know now that that those images aren't always like that. Thanks for the response. removing images.... Notgray.GIF  and Stillnotgray.png ... Dreg743 12:24, 2 July 2006 (UTC)
thread_title:  Subpixels -- new images 

message: I don't understand this image.  Can someone explain, maybe fix it or make a better caption? What is the relationship between the top row images and the bottom row, which are labeled only by different X values? Dicklyon 18:09, 27 August 2006 (UTC)
thread_title: New image removed

message: I'm a real technophile, but I read this article several times to no avail. I always thought that the pixel was just that little dot that is multiple colors... Now it's trying to say that it's something positively different?
Hmm... I think this could be revised so the people who haven't majored in English, Latin, and Arabic can understand it :)
~ Theta :D 06:57, 14 November 2006 (UTC)
replies: text: If that's all you thought it was, then you learned something, yes? I missed the Arabic part. Dicklyon 06:37, 19 November 2006 (UTC)
thread_title: I have to say...

message: The information I added has been removed (Dicklyon : revert long-winded not-quite-right stuff specific to 4:3 cameras with non-real numbers).
OK it might have been a bit long winded, but could it not have been edited instead of completely removed. I think the section could do with some more information. I'm not sure which bit was not-quite-right.
It was specific to 4:3 cameras, but this includes the majority of consumer digital cameras and video camera sensors.
Maybe the calculations were not needed, but I find it useful to be able to calculate the horizontal and vertical pixels counts given any Megapixel value.
The numbers in the table gave an exact number of megapixels (unless I am mistaken 1MP is 10^6 and not 2^20 as in the computer Mega).
I agree that these mathematical figures do not correspond to actual image sensor horizontal and vertical pixel counts, but it does not make it incorrect. The image sensors used have different pixel counts depending on the manufacturer.
I thought that this comment was useful, as I believe it is a common misconception :
'Note that a 6 megapixel image does not have double the number of horizontal pixels of a 3 megapixel image. It is not until 12 megapixels that the number doubles.'
Andy, 19 November 2006
:OK, maybe I overdid it, but it looked too hard to fix.  Of course, it can be recovered and reworked any time you or someone is motivated to do so.  Being specific to 4:3 bothered me, since DSLRs are usually 3:2 and there are other aspect ratios as well; if you're going to put equations, try to be more general.  The main thing that was not quite right was the list of sizes, which didn't correspond to any actual camera or sensor sizes of the stated megapixel ratings, and would therefore just confuse people who were trying to compare with known facts.  The stated relationships were also not applicable to a 3D pixel arrangement (rows x cols x layers) like in the Foveon sensors, nor to the pixel arrangements in SuperCCD sensors.  And finally, it was not really obvious why one would generally need to go from megapixels to numbers of rows and columns; what for?  It's hard to be sufficiently general there, since aspect ratios and organization and roundoff error are so variable; and those numbers are usually provided explicitly with any camera.  Using two sentences to point out that twice as many rows and columns means four times as many pixels also seemed like overkill, though it's a good point.  But is any of this needed to explain what megapixel means?  Why it is in the pixel article if it's about particular digicam organizations? Seems like it would go better in a digicam article. Dicklyon 06:36, 19 November 2006 (UTC)
replies: text: Dicklyon, in answer to your question: why would anyone want to go from megapixel to high/width and vice versa? Well, I do so on a regular basis, since when I am editing images on my computer I'm more used to thinking in terms of hight/width than in Megapixels. Also, hight/width is more informative since a number of "Megapixels" only tells you the total number of pixels (duh) and not the dimensions. Unless you also specify a ratio of course, because then you can calculate it yourself. As a matter of fact, I've been thinking about adding something like a formula for that too; the same thing that Andy was appearantly concerned with. The thing I had in mind was something like this:
If 
* x = image width
* y = image hight
* z = area (total number of pixels)
* r = image size ratio
Then
* z = x*y
* r = y/x
* x = y/r or (z/r)½
* y = x*r or (z*r)½
(sorry, don't know how to type a square root sign)
So that you could calculate any of the variables x,y,z,r if you know at least 2 of the others. For instance, if you only know the number of megapixels and a ratio (for instance: 4/3 or 3/2) then you can instantly calculate the width and/or hight without opening the image on your computer and reading the width/hight from the information that your picture viewer gives you.
Let me know if anyone else thinks this is useful information. Greetings, RagingR2 13:17, 10 April 2007 (UTC)
thread_title:  Megapixel section 

message: I removed this interesting contribution:
:The concept of digital still photography was conceived by Eugene F. Lally of the Jet Propulsion Laboratory/California Institute of Technology. Lally propopsed an on board all-optical guidance system for manned planetary missions. His paper "Mosaic Guidance for Interplanetary Travel" was published in 1961 at the annual American Rocket Society convention. The concept used an array of tiny light sensors in a mosaic pattern with each element refered to as a mosaic element that formed an image sensor. The sensor would record star and planet positions during transit for navigation purposes and when near an approaching planet would provide additional stadiametric information for guidance purposes of the astronauts onboard.  
This is fascinating, and I'd love to hear more about it.  If there's a verfiable source, that would be good to know.  But even if there is, how does it relate to pixel etymology? The concept of digital still photography predates that in a lot of image coding work in the 1950s, doesn't it? Dicklyon 03:09, 2 December 2006 (UTC)
replies: text: I think it makes sense, too.  I'd love to have a copy of it.  Can you email me dicklyon at acm dot org please? Dicklyon 04:07, 2 December 2006 (UTC)
thread_title: More etymology

message: I'm having confusion regarding UXGA resolution. The article specifies it as 1600x1200 while my camera phone that is 2.0 Megapixel has the resolution 1632x1224. I did some searching around Google and found that companies advertise this resolution (1632x1224) ALSO as UXGA and not by another name.
1600x1200 = 1.92 Megapixel (Advertised as 1.9 MP or pseudo-2.0 MP)
1632x1244 = 1.997568 Megapixel (Advertised as [true] 2.0 MP)
So which one is UXGA? --ADTC 04:23, 8 April 2007 (UTC)
replies: text: UXGA is 1600x1200, anything that says differently is just using it as a buzzword. There is no formal **GA for 1632x1244 69.138.81.129 02:39, 16 June 2007 (UTC)
replies: text: Sounds good.  What's your source?  Dicklyon 02:52, 16 June 2007 (UTC)
thread_title:  UXGA? 

message: The caption to the article's third picture: "Phosphor dots in a color CRT display bear no relation to pixels or subpixels"
I am really wondering what's going on here. I don't see exactly what is meant here, and the article itself does not seem to make that point. Any clarifications to be made? --Edwin Herdman 13:06, 10 August 2007 (UTC)
thread_title:  Pixel geometry, and pixels not related to phosphors? 

message: Just wondering - not wanting to start an edit war or anything...
1/ "Removing unsupported item" (WUQSXGA) from "standard" display resolutions (could argue that MOST of the really-high, non-consumer sizes are hardly "standard" anyway). I didn't insert that list, but out of curiosity I did a quick google for the term as it seemed such a silly drawn-out one. I can give you two links right off that first page (of 10+ pages) that seem to use it as a standard term, and moreover, the ENTIRE list seems to have been copied from another page (credited, uncredited? I haven't gone thru the reference list to check), with WUQSXGA being original to it.
: http://www.woot.com/Forums/ViewPost.aspx?PageIndex=6&PostID=1666128
: http://en.wiktionary.org/wiki/WUQSXGA
(the third one i just checked, on yahoo answers, seems to be from the same source as the Woot one, so I haven't bothered including it)
I suppose it simply being on the internet isn't really a credible source, so do we have them for all the sizes up to the one immediately below it?
2/ Removal of the pixel size section as being "off topic". How can the typical size of a pixel on a normal display device be off topic, if a list of typical pixel resolutions is on-topic? The two are interrelated. You could say the resolutions are offtopic also, as they're not intrinsic to the definition of what a pixel is. Megapixel and Subpixel could also be split off into their own small articles.
I mean fine, go ahead, edit it down from the size it was at, I know I rattle on, I was getting the info down first and maybe chopping it back after I'd got it written so I didn't forget a pertinent point. The lists were a bit long, the sentences run on. But zapping the whole thing is a bit much when it's smaller form had been happily sitting there beforehand. Revert it instead if you really have to (and I'll simply do my original intent, before things on this Talk board sparked my interest, which was to correct the "typical pixel sizes" to more realistic ones - NO ONE makes a 15" 640x480 monitor, as far as I'm aware, and a 19" 1024x768 would be a rare sight indeed. IE, change the numbers at the ends of the lines)
PS, the stuff about Dot Pitch would be UTTERLY offtopic for the LCD page, though I guess LCD pixel size could (also) go there. It was included to show that measurements for different display technologies are discrete and not directly comparable.
(Actually, i'm not 100% if I got to the point of submitting that, given it was *still being written* when the section was zapped)
Thanks, "82.46.180.56" 82.46.180.56 (talk) 16:25, 2 April 2008 (UTC)
thread_title:  Q about a couple recent edits