Talk:Pixel
|
|
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)
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!)
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)
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)
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)
Ok, looks like everything's been explained, and it all makes sense to me now; just have to clean up a bit now. Scott McNay 01:30, 2004 Feb 14 (UTC)
To do:
- Find or make a picture showing how sub-pixel font rendering (SPFR) helps. Put it on appropriate page
- Add mention on appropriate page of Apple (?) using SPFR on Apple II (?)
- Factor Pixel page so that image pixels are discussed separately from monitor pixels, ec. Right now, kinda mixed up.
- Find or make a picture showing pixel geometry for a typical digital camera. Mention that a digicam triad is quite large, due to having more green pixels than red or blue pixels. May want to un-redirect megapixel page.
- Clarify that pixels and sub-pixels are logical constructs, and triads and dots are physical constructs.
- Can someone clarify that SPFR really requires that the SPFR routine know the LCD monitor's native resolution, and/or works best when monitor is set to native resolution?
- Can someone explain how SPFR works on CRTs (see Apple II reference), when the image's location on the screen can vary from moment to moment?
Scott McNay 02:29, 2004 Feb 14 (UTC)
More info about SPFR available at http://www.grc.com/cleartype.htm
- Considering that apparently some monitors (CRTs?) have vertical stripes, that would imply that diagonal dot pitch measurement simply doesn't apply to them, since verical resolution would be limited only by the number of scan lines that can be squeezed onto the screen. Comment?
- Update pixel geometry to mention triads instead of pixels
- Merge triad and pixel geometry pages? Could edit/replace pictures to show both the geometry and the outline of a triad on the pictures
- Update triad to clarify that sub-pixel is not the same as a triad
Scott McNay 03:01, 2004 Feb 14 (UTC)
As i have always known and was taught, dot pitch IS a diagonal measurement. It is the measurement of the shortest distance between 2 like-colored phosphor dots (what someone started terming sub-pixel). Since a triad is made up of the 3 color dots in a triangle formation, as they are placed on the screen the measurement of dot pitch is always diagonal.
Dot pitch simply doesnt apply to an LCD screen, since LCD does not use phosphor dots, but rather a square made up of 3 tall rectangles in the primary colors. Sorry i do not know the term for that element in an LCD screen.
Im sure someone can clarify it more in the article.
- Enos Shenk 22:37, 14 Feb 2004 (UTC)
Does dot pich apply to Trinitron tubes? They have stripes also, I believe, and I don't have one to look at, but I would guess that the stripes are solid, not broken, meaning no vertical component.
So now the question is, are some companies actually reporting incorrect values for dot pitch? The first link below has some discussion on the subject.
- http://www.pctechguide.com/06crtmon.htm (starting with the dot pitch section)
- http://www.pctechguide.com/07panels.htm
- http://entertainment.howstuffworks.com/tv.htm
- http://computer.howstuffworks.com/monitor.htm (see page monitor4)
- http://computer.howstuffworks.com/question401.htm (none of the links at the end of the article are good)
Add note that SPFR is sometimes called "pixel borrowing".
After reading Wiki, HSW seems, well, mildly biased and incredulous. :)
(Forgot to put my sig above.)
Ok, I will edit (unless someone else does it first; I have some cleaning up to do around here, and headed out for a few hours with a friend this afternoon) the various articles to indicate:
- CRTs are analog and LCDs are digital, in the sense that on an LCD, a specific pixel can be guaranteed to correspond to a triad, whereas on CRTs, a pixel is most likely to land on varying parts of two triads (a pic showing this would be nice). Would it be accurate to say "Because of this vagueness, "native resolution" does not apply well to CRTs"?
- "sub-pixel" refers to digital displays
- "phosphor dot" refers to analog displays
- stripe pitch (sometimes called dot pitch) is a horizontal measurement for Trinitron CRTs
- dot pitch is a diagonal measurement for non-Trinitron CRT screens. For non-digital displays, the term is rather vague.
- SPFR only applies to digital displays
- SPFR seems to help on analog displays because it is an anti-alising method but standard methods give beter results for non-digital displays.
- Add an image for slotted mask. [1] (http://www.pctechguide.com/06crtmon.htm) shows the dot pitch being measured horizonally in this case, which I think is likely part of the cause of the "some companies measure wrong" issue.
- Incorporate other dot pitch caveats from [2] (http://www.pctechguide.com/06crtmon.htm).
- Etc.
Is someone else here better than I am with making pictures? I just have MS Paint, here... Scott McNay 17:47, 2004 Feb 15 (UTC)
| Contents |
New pixel article
I'm starting the new article at Pixel/new. The idea about tiles in mosaic came from Fuzheado. Scott McNay 06:16, 2004 Feb 18 (UTC)
Difference between px, pt, em
Is there an article which covers the difference between px, pt, and em measurements? These are used in drawing programs, css, etc. A single article that ties them all together would be nice. (also pica, ex, etc.)
css definitions: http://css.weblogsinc.com/entry/1234000933032102/
SVG definitions: http://www.xml.com/pub/a/2001/03/21/svg.html (what i was specifically looking for)
how it relates to font size in pt, how it relates to DPI, etc., etc.
- Omegatron 16:26, Apr 6, 2005 (UTC)
Rollback
I meant to edit a local version of this page, but instead edited the Wikipedia version. Is there a way to rollback to the previous version?
This article needs a lot of work
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)