Parhelia/few questions...

[az]

Someone please explain to me:

Does GAA really do the same as cleartype?

Doesn't cleartype do something else than just anti-aliasing fonts (what win95 with plus pack did, too), namely driving the red, green, and blue subpixels independently to achieve some kind of virtually higher dotpitch?

If this is really it, doesn't cleartype just add convergence problems (which might seem to "soften" the image of characters, but at closer inspection give colored borders)?

And, does cleartype only work with digital connections? (I believe no, since some of you stated it works with CRTs too, but there are digital CRTs)

Thanks

AZ

[Zed_L]

Parhelia/few questions...

1. Is glyph antialiasing ment to be used in TFT monitors only or can it be used in regular CRT-monitors too? (Windows XP's "Clear Type" works only in TFT's but technique is different than in GAA?)

2. Does WindowsXP support 10-bit colors or do we have to wait for XP SE or something?

3. I guess Parhelia does not support T&L, why is that?

[Pace]

1. Can you not use ClearType on CRTs?

2. 10-bit is supported, but upcoming Windows technology called Longhorn will utilise it fully.

3. It does.

[Tempest]

Here I'm happily using ClearType on my 19" CRT, so I'm pretty sure it works, and I'm kinda getting addicted to it

Microsoft says: "With Windows XP, ClearType delivers improved font display resolution over traditional anti-aliasing. It improves readability on color LCD monitors with a digital interface, such as those in laptops and high-quality flat desktop displays. Readability on CRT screens can also be somewhat improved."

ClearType supports text gamma correction too, it's pretty limited because it only provides six different options but it's there.

[Pace]

I used it too, one feature of XP I liked

[Zed_L]

ClearType is a software technology developed by Microsoft that improves the readability of text on existing LCDs (Liquid Crystal Displays), such as laptop screens, Pocket PC screens and flat panel monitors.
( from http://www.microsoft.com/typography/cleartype/ )

So it is not intended to use in CRT-monitors because of its different technolgy. I know you can use it on CRT-monitor but it sure does not make the text crispier actually it makes quite the opposite.

Parhelia's GAA, as I've understood it, is made differently. So I would like someone who knows for a fact, to confirm this.

And Pace, what do you mean that 10-bit colours is supported but not fully. What is missing in XP?

[Pace]

XP doesn't *use* 10bit, but you'll be able to use Parhelia with 10bit colour on it (e.g. in Photoshop etc).

Plus the fact that it renders internally at 10:10:10bit I believe, which will make the final output on 8:8:8 more accurate.

<i>Quoted from <a href="http://www.extremetech.com">ExtremeTech</a> &gt; <a href="http://www.extremetech.com/article/0,3396,s=1017&a=26865,00.asp">Matrox Storms Back into 3D</a></i>:

In the area of 2D Windows performance, GDI+ has explicit support for 10-bit color, where GDI pings the hardware driver for the number of bits per color, and reports this value to an app when it queries GDI. Because no hardware has supported this pixel format before, many 2D apps will ignore whatever value is returned and simply clamp down at 8-bits per color, since every GPU in the world supports that mode. Armed with this knowledge, Matrox designed a hook into their drivers that an app can ping to verify the color bit-depth. Apps that ignore this hook still get all 2D ops drawn in GigaColor (gradient fills, etc) in a way that is virtualized, but GDI will clamp data to 8-bit per color channel in many cases. For this reason, Matrox is providing its own 10-bit per color channel file viewer as a standalone application and as a plug-in to Adobe Photoshop. Matrox's standalone app allows a user to see the full 10-bit per color channel of a native image like a TIFF file on the Windows desktop. For the near-term, GigaColor's 10-bits per color channel will likely be used in professional markets (medical imaging, photo editing, etc.).

Looking beyond Longhorn (the next version of Windows that follows XP) Microsoft at its WinHEC 2002 conference divulged that Windows GDI graphics would require 10-bits per color channel accuracy. And because Parhelia can maintain 10-bit accuracy throughout its graphics pipelines, it would seem well-positioned for these future Windows graphics architectures.

The GigaColor technology will also be useful out of the box for DVD playback, since its 10-bit per color resolution is equal to that of DVD players and set-top boxes. Parhelia's 10-bit accuracy is carried through decoding, filtering and scaling as well as RAMDAC output, and we'll be curious to see how much of a difference Matrox's DVD playback quality provides versus its competition. Unfortunately, the computer graphics folks still have a little catching up to do, as many consumer DVD players are moving to 12-bit accuracy for color resolution.[/i]

Hope that clears it up

As for ClearType - you don't like it on CRTs?

P.

Edit: Removed italics on quote, looked bad

Also, here's a link to http://www.winsupersite.com - some Longhorn info will be on there.

[Zed_L]

Thx Pace, that sure cleared things up for the 10-bit part.

What comes to ClearType, I sure don't like it in CRT's, because it makes text just worse. (and the fact is, that it's meant to be used in LCD's)

Just would like to know if Parhelia's GAA is meant to be used in CRT's also and not only in LCD's.

[guillenv]

In order to provide accurate antialiased text, the graphics processor needs to account for gamma correction. The concept of gamma comes from the fact that the intensity produced by a cathode ray tube (CRT) monitor is proportional to the input voltage raised to the power gamma.

Text antialiasing with Matrox Parhelia™-512

Most current graphics accelerators do not accelerate antialiased text rendering. Windows, therefore, reverts to software acceleration, which has a
significant impact on 2D performance—in the order of a 30 per cent penalty. The existing graphics accelerators that report hardware acceleration
do not implement gamma correction for antialiased text rendering and, therefore, produce inaccurate text rendering.

Parhelia's GAA is doing in hardware what ClearType does in software with the benefit of being inteded for CTR's too, because it does gamma correction.

[Zed_L]

(time stamps sure are gone crazy)

Originally posted by az
Someone please explain to me:

Does GAA really do the same as cleartype?

Doesn't cleartype do something else than just anti-aliasing fonts (what win95 with plus pack did, too), namely driving the red, green, and blue subpixels independently to achieve some kind of virtually higher dotpitch?

If this is really it, doesn't cleartype just add convergence problems (which might seem to "soften" the image of characters, but at closer inspection give colored borders)?

And, does cleartype only work with digital connections? (I believe no, since some of you stated it works with CRTs too, but there are digital CRTs)

Thanks

AZ

I think that GAA differs from ClearType, but it seems that no one here knows for a fact. ClearType controls the three subpixels to get more horizontal points just like you said, and also might give some color glitches also.... GAA as I see it just regular antialiasing and I think it works similar no matter what kind of monitor is used.

Cleartype works in analog connections too, and can be switched on when using CRT-monitor too, even though it's supposed to be used with LCD's. (unlike GAA?)

[DentyCracker]

Zed, I find quite the opposite to you in that ClearType looks better on both LCD and CRT monitors.

[Rags]

Originally posted by DentyCracker
Zed, I find quite the opposite to you in that ClearType looks better on both LCD and CRT monitors.

Ditto on that.

Hey, I love your Avatar!

Rags

[DentyCracker]

Love your avatar Rags. Hey perhaps Cleartype looks bad on nV cards

[Zed_L]

Originally posted by DentyCracker
Hey perhaps Cleartype looks bad on nV cards

That actually might be the truth. You know, when I installed WindowsXP, I couldn't get CounterStrike working properly with my G400MAX. I tried everything and finally contacted Matrox. They sent email that stated that it was known problem and should be fixed in next drivers.

Well I couldn't wait and bought used GeForce2GTS. CounterStrike works OK but I am really disappointed to the 2D picture quality. It's a bit blurry and what's worse, it kind of looks like my refresh rate was too low even if it's not. When I use ClearType it somehow gets worse, and I got my head sick after a while.

If I can't wait until the release of Parhelia I'll put my dear old G400MAX back. I'm sick and tired of this GF2's picture "quality".