Cleartype In Depth 142
spectecjr writes "Looks like Microsoft have at last released some detailed information on their ClearType technology. It involves a whole load of Fourier Analysis to come up with the optimal distribution of color energy and to reduce color fringing. You can read the paper and more indepth info in PDF and gZipped PostScript, as well as the paper submitted to the IEEE Signal Processing Letters journal PDF. Samples of ClearType vs. standard anti-aliasing are up online too."
Don't bother going... (Score:2)
From the site: "In order to view a sample of the optimal ClearType filters, you must view this page on an LCD with RGB stripes. You will not be able to see the full ClearType effects on a CRT. Some LCDs (such as in the iMac), use BGR stripes, which will not work with these samples."
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Compaq dropping MAILWorks?
This can't be innovative technology (Score:3)
Look at it up close (Score:1)
Why not? "Don't bother going..." (Score:1)
How Long... (Score:1)
There must be some mistake.. (Score:2)
Slashdot groupthink had convinced me that MS never creates anything original... hmm... must think... *smoke* brian overheating...
*kaboom*
It was a joke! (Score:2)
What about the prior art from Apple? (Score:1)
Yes, well, WITH a CRT... (Score:1)
a) cleartype samples appear a bit sharper/darker than "traditional" anti-alias techniques, when viewed from monitor-eyeball distance. Closer inspection revealed some aliasing effects on the cleartype sample.
b) cleartype looks just a hair better at small font sizes.
c) the difference between cleartype and traditional anti-aliasing, on a CRT rather than an LCD, is pretty insignificant.
If I can get either of my laptops semi-reliable for more than a few minutes, I'll post some info on the difference. So far, my impression is that this is redundant technology that would mostly benefit Microsoft rather than the licensors of other anti-aliasing technology - perhaps the impetus for the creation of cleartype in the first place.
Innovation? (Score:2)
http://grc.com/cleartype.htm [grc.com]
Re:It was a joke! (Score:2)
Don't mind, troll alerts are blossoming everywhere. Look at most of TRoLL's production [slashdot.org].
gzip?? (Score:1)
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Truth or more Lies? (Score:1)
And of course this does absolutely nothing for screens other than LCD..
jaggies (Score:1)
[edm2.com]
http://www.edm2.com/0603/opengl.html
Re:Don't bother going... (Score:2)
It doesn't exist until microsoft invents it... (Score:1)
Yes, your still have to have an LCD to see that it works
checkout:
http://grc.com/ctwho.htm [grc.com]
Re:LCD iMac (Score:1)
Or do they perhaps mean the iBook?
Certainly I have found that different Apple LCD screens have different pixel orders
Big deal (Score:1)
Teeny Fonts (Score:1)
Now mebbe if Micr'Soft replaced all 'content' on tha' web with -1 font-sizes -ClearType'd look even better by comparison.
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Keep in Mind (Score:2)
If ClearType is computationally equivalent to an (example) 8-tap anti-aliasing method than it is a major breakthrough. (can't believe I'm saying something positive about M$...eww...)
I like my jaggies (Score:2)
All I have to do is iterpret symbols on the screen as letters, the more you dull them out the less information can be packed into the screen. (Of course that would be one wacky font.)
Besides, this ClearType also requires a color display adding to the battery draw...
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Eric is chisled like a Greek Godess
Yick, hurts my eyes. (Score:4)
Back when this was first announced I thought it made sense and would work great. I even read a few pages which showed how Apple did the same thing and loaded the samples on there up on a few screens to see how they looked. Yeah there was a difference but nothing major.
Now this comes across with what sounds like samples made using the exact algos that MS is touting as their great new innovation. So I pull out the old palmtop and laptop and check the page out.
But this looks like hell to me! I can see major color fringing and in those text waterfall examples I see rainbows in the CT examples that are so prominent they make it harder for me to read than the AA example! Yuck!
Does anyone else notice it as much as I do? Or are my eyes just abnormally color sensitive?
Anti-aliasing on conventional monitors. (Score:4)
Cleartype is basically antialiasing which takes note of the way in which the LCD screens make up their pixels. From the comparative samples, it's difficult to compare the two samples given on a normal (i.e. CRT) monitor. I strongly suspect that this is not going to make such an impact on CRT-based techniques for several reasons. The conventional monitor scans a modulated electron beam across a mask before hitting the coloured phosphors which make up the display. Despite the regular display patterns of the mask, a pixel on a conventional CRT could line up with any combination of the coloured phosphors, as the start of each pixel could be on any of red/green or blue phosphors. The Cleartype technology relies on being able to make use of the arrangement of single-coloured pixels to enhance the imagery (and yes, I do believe it can make a difference) and must therefore be aware of the mapping from the resolution of the image on screen to the resolution of the actual screen matrix itself.
Something does strike me as odd in the samples though. One of the things that ideal anti-aliasing should do is give a completely even weight to every letter/symbol in a font (assuming that the base font definition is designed with this in mind). However, scrutiny of the samples seems to suggest that either the font they are using is subtly broken in this respect, or that the anti-aliasing and Cleartype render used here is not ideal - take a look at the weighting of the 'x' character, and slightly less of a problem is the 'k'. This could be hinting gone wrong, or a bad font definition - I'd be interested to know whether it looks better on an LCD screen.
Cheers,
Toby Haynes
Microsoft Research (Score:4)
Re:Don't bother going... (Score:2)
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Ski-U-Mah!
Stop the MPAA [opendvd.org]
Re:I like my jaggies (Score:1)
Where the heck did all that karma come from? damn +1 bonus, I want to earn my place.
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Eric is chisled like a Greek Godess
The relevant freeware (Score:4)
Free and Clear [grc.com]
However, his discussion doesn't seem nearly as complex as the one we have linked in this article. My feeling is that the idea of sub-pixel manipulation is one of those "floating revelations" that recur to more than one clever mind, but that MS Cleartype is the first practical application.
Oh, and here's the cleartype site at MS. Be sure to view it with an LCD screen - otherwise you won't get the benefit due to the triangular distribution of color spots on a CRT:
MS Reader [microsoft.com]
-konstant
Yes! We are all individuals! I'm not!
Re:Yick, hurts my eyes. (Score:2)
Steve Gibson's ClearType Demo (Score:1)
Someone should ask Steve Gibson to opensource his app so that we can incorporate this tech into X display server (it's written in ASM so it's very fast to).
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GroundAndPound.com [groundandpound.com] News and info for martial artists of all styles.
Re:There must be some mistake.. (Score:2)
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Ski-U-Mah!
Stop the MPAA [opendvd.org]
Orange on the left, Blue on the right (Score:1)
I'm sure the analysis to get these results is much more sophisticated. Without a doubt it will be or is patented, but wouldn't a poor-man's approximation of this be to anti-alias (pixel interpolate) with blue tints on the right and orange tints on the left (instead of grey as is more standard)?
I'll bet the algorithm is much simpler if you do it that way, and you'd probably get 90% of the results with 10% of the effort.
Re:Innovation? (Score:3)
Since LCD monitors were not exactly prevalent at the time of the Apple II, and since MS Cleartype depends strictly upon the existence of a tri-bar distribution of colors that is found only in LCD's...
Let's just say that having a bright idea and actually implementing that idea are two very different things. How many people in the
-konstant
Yes! We are all individuals! I'm not!
Re:Yick, hurts my eyes. (Score:2)
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Ski-U-Mah!
Stop the MPAA [opendvd.org]
A little more on anti-aliasing (Score:3)
Now, we'll encounter some problems. In a traditional pixel-drawing scheme, we would color all squares completely covered by this diagonal line, and any other square, even those partially covered by the line will not be colored.
Zoom back from this drawing, and you have a very jagged, aliased line.
Now the anti-aliasing scheme solves the jaggedness by a simple yet clever solution; the squares are shaded depending on what percentage of their area is covered. That is, if a square is 95% covered by the line, it will be very dark, and if it 5% covered, it will be very light. Zoom back from this, and you have a nice smooth anti-aliased line.
Note that other anti-aliasing methods exist for differrent things, but the above is mainly for simple line drawing. For example, when anti-aliasing is done on a 3d rendered scene, a typical solution is to slightly shake the camera and re-render the scene, then blend the different renderings (this is known as oversampling).
Now, this cleartype technology seems interesting. I'm not sure how it works, but judging from the examples given, the fonts look a bit "fuller" when larger on the screen. Also, very small fonts are very easily read, whereas in an antialiased scheme the smaller fonts are difficult to identify (this is probably because the antialiasing algorithm has trouble dealing with sub-pixel drawing instructions). One downside of cleartype, however, is that I noticed a fair amount of green and red color fringing on the small-to-medium fonts. I suppose this type of distortion is a side-effect of taking advantage of sub-pixel drawing technology.
Re:Don't bother going... (Score:1)
Re:Don't bother going... (Score:2)
You can download a demo of the technology used behind ClearType, at Steve Gibson's page:
http://grc.com/cleartype.htm [grc.com]
It is configurable for all sorts of LCD layouts, including BGR and RGB. Unfortunately, it runs only on Windows, so this probably won't help you if you have an iMac... but perhaps you could do screen captures then view the graphics on the Mac?
Of course, this was all done over 20 years ago, with the Apple ][: it displayed color, but internally everything was black and white! Due to the way the NTSC television signal works, it could create color by placing thin white vertical lines very close together in precise positions. It did this, essentially creating more subpixel resolution. The application was different, using black and white pixels to create color (essentially opposite to what is done now, using color pixels to create more black and white resolution), but the underlying technology solution was the same.
I just hope Microsoft doesn't try to patent this! Hopefully, the Patent Office will see the mountain of prior art that is the Apple ][.
actually (Score:1)
IBM Research Scientist's Comments on ClearType (Score:5)
sigh (Score:1)
And of course this does absolutely nothing for screens other than LCD..
This is akin to complaining that the latest rechargeable laptop battery technology isn't good for anything other than laptop computers. CRT's don't even need this technology-- it's designed specifically to enhance the text quality on portable color LCD devices.
Re:There must be some mistake.. (Score:2)
brian is overheating? poor brian. maybe he should go jump in a lake.
New? (Score:1)
Some people have too much time on their hands. Putting a shiny label on something to sell it better is kinda, ironic. It's sorta like changing the date on a carton of milk...
Perhaps it is innovative because it suchs more of your processor into viewing text (whoopee!)
Looks nice on my laptop (Score:1)
Innovation (Score:2)
Several people have already pointed out that ClearType does not represent innovation on Microsoft's part. Here is a related point for your consideration.
When the Free Software / Open Source community creates something innovative, anyone can use it in any way, improve upon it, incorporate it into any kind of tool. Everyone benefits. This is the paradigm of science.
When a corporation such as Microsoft creates something innovative and keeps it proprietary, no one can use it in any way except as the corporation permits. The lion's share of the benefit goes to the corporation, and further innovation is stifled. This is the paradigm of intellectual property.
Anyone, including a corporation, has the right to handle their creations as they see fit...but where do you want to go today?
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Re:What about the prior art from Apple? (Score:1)
It wasn't specific for putting text onto the screen, but allowed one to put finer, more detailed hires graphics onto the display just by doing some calculations and setting the colour of the pixel right; depending on what the colour was set to, a pixel would be shifted about 1/2 to the left or right on the monitor. The upside was that it almost doubled your x-resolution on the screen. Unfortunately, you really had to turn the colour on the monitor down, otherwise you'd get some horrible colour fringes around all lines and stuff.
They'd even implemented some routines in machine language to do all this quickly and were accessible from applesoft basic using the good ol' ampersand. Anyone else remember that?
Fun stuff...
--C
Re:Look at it up close (Score:1)
Looks totally pointless on my CRT though but I guess that's the point as it 'needs' an LCD.
Oh well, at least it will keep the baby-bills busy.
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Idea Database (Score:1)
I've been thinking about this for a bit. A lot of good ideas are lost because of technical problems. Myself I have a big list of things I want to do "when know how to". How about creating an "idea database". Anyone with a good idea can enter it. Others can browse those idea's to find a solution to a problem they have. If they find someone they can contact the original author to discuss it further and/or help him implementing it.
Re:Innovation? (Score:2)
OK, but you tell Steve he's wrong...I know him, and there's no chance I'll do it.
Another Microsoft "Innovation" (Score:4)
The Apple II doesn't really do this. It uses the properties of the NTSC colorburst signal to create color from a synchronized high-resolution monochrome signal. The physical "subpixels" on the CRT can't be aligned to this signal, and the end result is fuzziness, not clarity. The R,G,B phosphors on the screen are not directly addressed.
CRT's and even analog LCD's don't gain anything from this, as this technology needs direct access to the R,G,B elements of the display to create antialiased text that is as sharp as possible. It even needs to know the order of the RGB elements. This done through wholly digital displays that directly address the color pixels on the display, such as an LCD on a laptop. The next step would be to make this independent of the display type, with tuning tools or profiles for individual display devices.
Television does this naturally, being a wholly analog system. Point a color camera at some text, and the edges of the text will fall on the color elements within the camera, irregardless of arbitrary pixel boundaries. If you magnify a still image on a TV set, you'll notice that any sharp edges are defined independantly of the positions of the color elements, and they are "smooth". In contrast, any computer-generated edges show a bias toward pixels, causing some jagginess in even the best anti-aliased graphic. Of course, if the source camera and the receiving TV set have different color element geometries, the result will be a little off.
Whatever you call it, this is antialiasing taken to the max. I'm glad that someone is taking it seriously, even if it's Microsoft. CG for television should take notice, too, to try to simulate the natural look of purely analog signals.
Re:The relevant freeware (Score:1)
I'd sigh too if I didn't read the link! (Score:1)
The Apple II's highest resolution mode was 280 pixels horizontally by 192 vertically. However, this was really the 'sub-pixel' resolution. (Similar to the example above where an 800 pixel wide LCD is really 2400 sub-pixels wide.) The Apple II's display generated two sub-pixels per pixel. On an LCD display every third sub-pixel is Red, Green, or Blue and all three must be turned on to get white. On the Apple II, every other sub-pixel was green or purple and they both needed to be turned on in order to get white.
here's more
But thanks to Apple's built-in sub-pixel technology, white pixels were often composed from each half of adjacent whole pixels to yield a much smoother result.
Re:sigh (Score:1)
If you follow the links, you'll find Apple did in fact use sub-pixel rendering.
Re:Innovation? Perhaps for handhelds (Score:2)
So why only LCDs? What about CRTs? I suspect what Microsoft is really after here is the handheld market. They'd like for PocketPCs leap ahead of Palm OS at least as far as display clarity goes. It may seem like a minor battle but Joe Consumer standing in Best Buy looks at chunky Palm OS two-color screen then sees bright and crisp PocketPC screen and buys that instead.
What I find curious is ClearType has been presented at a few conferences and white papers submitted to IEEE yet I don't see any clear statement on how/if ClearType will be treated as a public standard, or released under some sort of licencse, or jealously protected by zealous IP lawyers. Could it be a case of adopt-now-and-we'll-bill-you-later? Maybe I just can't find a link to the license agreement. Whatever.
Re:Innovation? (Score:1)
Sure -- as Steve Jobs put it, "Real artists ship." But sub-pixel rendering was widely used in the Apple ][ days. Among other sources, it's documented in the MS Basic Interpreter refs.
Since LCD monitors were not exactly prevalent at the time of the Apple II, and since MS Cleartype depends strictly upon the existence of a tri-bar distribution of colors that is found only in LCD's...
True, the older method deals with two pixel colors. That's the basis for the "unprecedented" in LAS VEGAS -- Nov. 15, 1998 -- Tonight at COMDEX/Fall '98, Bill Gates, chairman and CEO of Microsoft Corp., unveiled an unprecedented innovation in font display technology during his keynote address. ?
It's all in the LCD sub-pixels. (Score:2)
RGBRGBRGB
RGBRGBRGB
RGBRGBRGB
Traditionally, we treat any group of 'rgb' as a pixel, so.. to make a 'white' display, we need *any* 3 adjacent pixels.. they use this fact to effectively triple horizontal rezolution. ie: Insted of 50%r100%g50%b, on a diagonal line, the next one would be 100%g50%b50%r, etc...
Re:Idea Database (Score:1)
engineers never lie; we just approximate the truth.
Three questions towards innovation (Score:1)
1) Is the main purpose of this technology to provide a technically irrelevant selling point for the Pocket PCs?
2) Is the main purpose of this technology to justify the cost of the processors to run the bloated software?
3) Is the main purpose of this technology to show, when two PDAs are running side by side with ClearType, that the Pocket PC is the better machine(given the optimization)?
When we know the answers to these questions, then we can decide whether this is innovative or just annoying.
Re:A little more on anti-aliasing (Score:2)
In an LCD, you have rgbrgbrgb... rather than saying that a pixel is 'rgb'.. a pixel can actually be any three adjacent subpixels, as the full color group will still be present. Effectively, they triple their horizontal resolution.
Re:Don't bother going... (Score:2)
Wow, this is the second Slashdot story in the past week to remind me of those halcyon American-using-Sinclair days. Probably explains the Police kick I've been on lately. Ahh, the '80s!
Every day we're standing in a wind tunnel
Facing down the future coming fast - Rush
Re:Steve Gibson's ClearType Demo (Score:2)
asm is moderately useless for putting into X, it has to be portable.
Re:sigh (Score:2)
I seem to remember some C64 demos that programmed the video hardware to get subpixel accuracy, but I think that was more of a hack of the hardware.
nojw
Re:Anti-aliasing on conventional monitors. (Score:3)
Another stupid thing about the images is that in neither of the images (Cleartype nor antialiased) is font hinting used. IMHO they should have compared hinted antialiased with hinted cleartype (with three times the horizontal resolution). Windows' font engine has hinting and antialiasing.
Hinting, for you who don't know the term, is a way of snapping the font outline to the centers of pixels before rendering. This minimizes stupid solid grey lines in the edges for a well hinted font. The problem with hinting though, is that the quality of the hinting is dependent on the skill of the font designer.
Re:Don't bother going... (Score:1)
R G B R G B
B R G B R G
R G B R G B
There is a shadow mask used to control the 3 electron beams. Everywhere you look there is always a triangle of RGB. I have never heard of them called stripes, but I guess you could. This tends to show the real reason the sceme works though.
Re:Don't bother going... (Score:2)
Off-topic, but have you tried viewing PDFs in GhostView? They work nicely, since they're basically PostScript anyway.
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Standard Engineering Practice from the 1980's (Score:2)
See Color LCD Panel Subpixel Rendering [purdue.edu] by Prof. Hank Dietz, December 15, 1998.
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Re:Innovation? (Score:1)
Except for the small fact that you don't need to use a modern LCD panel to use this technology. I used to program quite heavily for my old Apple //c, and on the color output (plain old NTSC) this was made use of in several applications. Televisions *do* use 3-color "pixels", and at least DeluxeDraw used this technique to draw "straight" lines on a page. Also, the rendering engine that Sierra came out with (the name escapes me...) would use this technology to draw vector graphics on the screen.
The wheel is turning but the hamster is dead.
About the delay... (Score:1)
Disappointing... (Score:1)
On the other hand, both examples look much better than the non-antialiased text I'm used to looking at under Linux... :-/
Re:Innovation? (Score:2)
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Re:The relevant freeware (Score:2)
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Re:Standard Engineering Practice from the 1980's (Score:1)
The thing is... his method appears to use a simple box-filter; not the complex filter used in ClearType.
The difference may be marginal; ClearType certainly looks better on my HP Jornada than your advisor's solution though. And the difference is what counts; it's the type of filtering algorithm invented that is patentable - and that algorithm is an order of magnitude more complex than the simple one your advisor came up with (similar to Steve Gibson's one).
Not to mention the other gears and cogs involved in getting it up onscreen; they're a siderunner.
Simon
Re:Don't bother going... (Score:2)
Re:Innovation? (Score:2)
As any television engineer will tell you though, there's no way of addressing the INDIVIDUAL phosphors on the screen; so no, Apple didn't have "subpixel rendering".
What it does have though is the ability to push its monochrome signal (in composite video/NTSC form) at a high enough frequency (ie. high resolution) that it went out of the defined NTSC bandwidth for a luma signal, and poked its way into the chroma. This is why two pixels together ended up as white (or black); because the width of the on/off pulse was wide enough to be encompassed in the luma part of the signal.
When you half that width, you end up with the pixels poking into the chroma part of the signal; depending on the phase (ie if it's the left or right hand part of the pixel pair that's set), you end up with green or magenta.
So it's not quite subpixel resolution. And it's useless for antialiasing (the luminosity distribution between white, black, green and magenta has obviously not been chosen to give antialiasing a helping hand). Well, you can get a half-level, I guess, if you use Magenta. But that's about it.
In conclusion, Apple had a way of forcing color out of a monochrome signal (much like the ZX81, which gave you blue and yellow on a PAL screen if you futzed with the output display), but it wasn't anything to do with splitting pixels, or subpixel rendering, or any kind of attempt to increase the effective resolution of the display. Because believe it or not, if you magnify that television display, more than one phosphor will be lit-up green for the green pixels, and more than one phosphor will be lit-up magenta for the magenta pixels.
Of course, getting Steve Gibson to acknowledge this (especially as he dissed Microsoft as copying Apple, and then implemented his "Free n Clear" with a several-orders-of-magnitude more complicated algorithm to reduce color fringing without batting an eyelid) is a task left to the reader.
Simon
Re:Three questions towards innovation (Score:1)
Re:Don't bother going... (Score:1)
Well, LCD screens don't use electron beams. And we are talking about LCD screens here... they use colored filters, with the colors laid out in stripes.
Re:Don't bother going... (Score:1)
Re:There must be some mistake.. (Score:2)
Don't be such a troll, especially when you don't know what you're talking about.
You guys... (Score:1)
Re:Big deal (Score:1)
A whole load of Fourier Analysis... (Score:1)
Moderate this up please (Score:1)
Re:Don't bother going... (Score:1)
The iMac does not have an lcd, silly. Maybe they meant iBook.
Tom
Interesting technology. (Score:2)
My question is, will this technology be relevant once monitors at 3072x2304 are common? The extra resolution would surely be wasted on making your browser window or text editor larger -- because your eyes can only read so much. But if you used it to enchance the readability of everything on the screen, making all your edges sharper -- it could make things much easier to read, scale, and enjoy.
1024x768 screens are fairly uncrowded. They give you lots of space to overlap windows when you need to work between a couple of applications, and provide a nice size for working in one application. But once you go past to resolutions of 1280x960 or 1600x1200, you begin to not see any useful gains. "Everything" begins to shrink, leaving more and more useless white space, while using an exponential increase in video ram and monitor bandwidth/scan time.
Perhaps the real application of a technology like this is not for using the properties of LCDs to fake more pixels, but in rendering low-resolution 1024x768 screen on a high resolution 3072x2304 screen with anti-aliasing and proper kerning, and other smoothing techniques to make it as crisp as any piece of paper. This could make 2D cards require an extra bit of logic on the silicon, but the benefits could be many.
I'm sure 3D graphics would benenfit too, considering how anti-aliasing could make the "low" resolution of 1024x768 look fine (the Voodoo5's FAA makes lower resolutions just as good looking as higher resolutions withouth FAA). Instead of worrying about larger memory usage by video cards, you could just work towards a fixed target, and let the monitor's increased resolution + the logic on the card do full screen anti-aliasing without as much special logic as the Voodoo5 employs, and it'd look crisper because you actually have those extra pixels to use (instead of just relying on the eye to average the shades of adjacent pixels).
Just a thought
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Cleartype in depth (Score:1)
Basically the paper demonstrates... (Score:2)
And X still doesn't have anti-aliasing? (Score:3)
A) A huge, major rewrite.
B) To be replaced with something else.
Berlin looks very promising. True it uses CORBA for its API services, which sacrifices speed, but even at the beta level that it is in, it already has nifty features like anti-aliasing support, and a totally cool imaging model. Also, it is designed to be extended cleanly.
Re:A little more on anti-aliasing (Score:2)
This is one particular implementation of an antialiasing technique, which you might see listed in the appropriate literature as "reconstruction via box filtering" or "weighted area" sampling. It can be fairly simple and effective to implement, but it is far from the best possible results. Using box filters for reconstruction overly blurs the underlying "perfect" image that you are trying to reconstruct. In digital signal processing, you would typically use a sinc(x) filter (sinc(x) = sin(x)/x) to reconstruct, which is theoretically perfect, but expensive to evaluate. More moderate filters based upon cubic bsplines walk a pretty good line between sharpness and expense.
This is a type of oversampling that is currently getting alot of mileage because graphics hardware from SGI and now other graphics companies can do this in hardware, typically using an "accumulation buffer". This type of antialiasing isn't without its own share of artifacts, resulting from the correlations between subpixel locations. Oversampling in general has been around for a long time, it was part of Turner Whitted's original 1980 raytracing paper.
Beautiful on Acer laptops. (Score:2)
Re:What about the prior art from Apple? (Score:2)
Good people, not home grown (Score:2)
Whether Microsoft Research will be a long term fixture among top industrial research labs remains to be seen. It's also unclear whether Microsoft Research will be any more successful at technology transfer into products than other labs. Apple, for comparison, used to spend a lot of money on research (Gates was bragging publically he didn't have to spend any, he'd just take Apple's results) but disintegrated within a couple of years when the company wasn't doing so well.
With their wealth and promise of stock options, Microsoft has had an easy time luring away people from other research labs until now. Losing so many good people has been pretty bad for those other labs, as you can imagine, and that has given Microsoft Research the reputation of begin a raider (in line with the generally aggressive stance of Microsoft).
don't see much of an improvement (Score:2)
Does it actually look like a significant improvement to you?
Re:And X still doesn't have anti-aliasing? (Score:2)
If anti-aliasing requires using different X calls (and thus does not cause existing programs to antialias) I will kill the first XF86 representative I see.
(To be realistic, I expect antialiasing to work if a truecolor visual is used and copy transfer function is in use.)
The only "extension" I want is to add a simple X call: XSetTheDamnFont("Name of font goes here", point_size); This should ALWAYS set the font no matter what garbage I put in the name, set it to a default font if not found. And I should be able to get italic if the string contains the word "italic" in it.
Well, I could also use UTF-8 encoding.
My analysis (Score:3)
A better filter for text would be a cheapo box filter. The worst it can turn a 1-pixel black line into is two .5 lines that are adjacent. Adjusting for the screen gamma (their examples *do* do this) will make a much more "even" result than this fancy filter (and would be dozens of times faster). In particular the thin lines would all appear to be much closer to the same weight (it is also necessary that the original binary image have lines of even thickness).
The "cleartype" I think looks somewhat sharper because it uses this simpler filter. You can also see dithering artifacts all over the white area to the right, so I believe they are rendering at 3x width and then translating this to the rgb values of each pixel, but using something like error diffusion to keep the average total color rendered "gray". I think they should reset the error after some number of pixels of solid color because your eye will not see this:
RGBRGB.....RGBR
as more red than this:
RGBRGB.....RGB
This would get rid of the dithering artifacts on the right.
In any case it actually is an innovative idea. The truth about innovative ideas is that they seem quite obvious once somebody thinks of them. It also means that it is almost impossible to stop real "innovation" from being used by everybody, since just seeing the output provides enough information for the innovation to be recreated. In fact I would expect this to appear in lots of commercial and free products quite soon.
For a real discussion of sub-pizel rendering (Score:2)
Please make a note of the following: (Score:2)
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Re:Anti-aliasing on conventional monitors. (Score:2)
The effect may not be as pronounced on a vertically striped CRT as on an LCD, but I can actually see the difference on my Sony Trinitron (tm) monitor. The text is noticeably sharper in all the sizes.
Interestingly, though, the basics for this technology has been around for a while. Display stripes are not the only source of color-biased (and hence reverse biasable) geometric effects. Image pickup devices such as single tube video camera of a couple decades ago, and current color CCD cameras, have these effects even more extreme because of the more coarse striping that exists.
I would suggest that a correction for the effect of the display device could be applied in general to the whole video signal being displayed, and there would be improvement overall. Then type hinting would still have to take into consideration that the snap points aren't the same for each color plane (part of what is apparently going on in Cleartype, anyway).
Screen capturing (Score:2)
Re:Another Microsoft "Innovation" (Score:2)
No, but there is still a color shift effect which results from using pixeling to effect NTSC "modulation". I remember seeing at least one program on my old long-gone Apple ][ which attemtped to compensate for this effect. That was limited by the lack of ability to change pixel value. I did play around with time-coding it to get that effect anyway on long-duration color photographs made from the CRT screen.
Yes they do. It may not be as much, and certainly more complex to compensate for since you don't get to syncronize the effect at the pixel level. But a CRT, especially a vertically striped one, has the effect of shifting the color planes relative to each other at sub-pixel levels, and the effect used in ClearType partially compensates for this. The correction is a matter of degree and probably could be optimized for a specific CRT tube at a specific scan geometry. But it is very real and I can visually see it in the images from the Microsoft Research page. What ClearType is probably also doing is adjusting the snap points as well so that hinting applies differently in different color planes (and thus not necessarily shifting the color planes by the same amount for each character cell).
When it comes to single tube (vidicon) and color CCD image pickup devices, then television actually has more of a problem with just the color plane shifting effect. I remember reading an article in one of the broadcasting tech journals at the time regarding this, and how some circuitry was used to correct this in the YUV color space, as opposed to the RGB color space. It happened to mention that CRT displays introduced a muted form of the same effect, but could not be corrected for because of all the variations that existed. I remember thinking at the time that it would be relatively simple to correct for that for a Sony Trinitron display, if I could first split the video into RGB signals, then apply a time-base corrector. It would not have been cost effective for a consumer device. But the sharp, crisp, image I saw on Tektronix studio monitors back then (late 1970's, when I worked in broadcasting) made me wonder if they were employing some of this. Perhaps we should inquire of Tek as to what research they have done with this, as well as Kodak, which I know has done research to correct things like this in their CCD cameras.
Re:A whole load of Fourier Analysis... (Score:2)
I was definitely wondering about that. I suspect a simpler approach (and certainly not patentable in the context of the clear thinking minds of /. readers) is to simply perform the type rendering, and hinting, in separate color spaces shifted by an amount intended to correct for the particular display in use, be it discrete LCD, analog LCD, or striped CRT. Still, that alone is not the whole effect. There is an effect of the fuzziness of the edges varying by horizontal position with respect to pixel alignment, and this, too, varies by color plane (absolute for discrete LCD). The Fourier Analysis could come into play to correct for this, though I suspect some pre-generated masks would really be all that would be needed.
Re:Another Microsoft "Innovation" (Score:2)
The reason this comes to so many people's minds (and the real proof of the similarity, really), is probably the fact that the colour fringing on the Cleartype samples looks a lot like the colour fringing on an Apple ][ display. Try running an emulator with the colour burst simulated if you've never seen it firsthand. Quite the nostalgia trip actually.
As for whether it's really any good, well, it's merely ok. I'm looking at it on a powerbook 2400 screen (RGB striped 96dpi display pretty similar to what's in colour PDAs), and the difference with the standard grey antialiasing isn't all that great; arguably the colour fringing makes it six of one, half a dozen of the other (ObPrisoner). It seems a little clearer if you look at a gamma lower than your real screen, or maybe mine really is at 1.6 these days. I wouldn't pay extra for it, anyway.
Re:Yick, hurts my eyes. (Score:2)