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Why does the Prime use anti aliasing on text?
07-08-2019, 02:36 PM
Post: #1
Why does the Prime use anti aliasing on text?
I recently learned that the Prime uses anti aliasing on text and I am unsure why it's necessary. Could the text have been left alone? Why was anti aliasing chosen over subpixel rendering? Personally, I don't care that much for the anti aliasing, is there any way to reduce it, remove it, or turn it off?

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07-08-2019, 04:34 PM (This post was last modified: 07-08-2019 04:35 PM by Joe Horn.)
Post: #2
RE: Why does the Prime use anti aliasing on text?
Pretend that you have to look at the following two screens all day, and read the fonts as displayed here. Both have unique benefits and drawbacks when compared with each other. But which one would annoy you the least at the end of a day of use?

[Image: MediumFont.png] [Image: MediumNewFont.png]

My personal opinion is that the dithered font is slightly BOLDER than the un-dithered font whose strokes are TOO THIN for long-term comfort. I can read the dithered font at a faster glance than the un-dithered font. Yes, the un-dithered font is "cleaner"... but that doesn't make it more readable. For me. Apparently opinions differ, which is fine. Please share yours.

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07-08-2019, 05:49 PM
Post: #3
RE: Why does the Prime use anti aliasing on text?
(07-08-2019 04:34 PM)Joe Horn Wrote:  Pretend that you have to look at the following two screens all day, and read the fonts as displayed here. Both have unique benefits and drawbacks when compared with each other. But which one would annoy you the least at the end of a day of use?

[Image: MediumFont.png] [Image: MediumNewFont.png]

My personal opinion is that the dithered font is slightly BOLDER than the un-dithered font whose strokes are TOO THIN for long-term comfort. I can read the dithered font at a faster glance than the un-dithered font. Yes, the un-dithered font is "cleaner"... but that doesn't make it more readable. For me. Apparently opinions differ, which is fine. Please share yours.

I'd much rather look at the one on the right (dithered)

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07-09-2019, 03:15 AM (This post was last modified: 07-09-2019 03:16 AM by Tim Wessman.)
Post: #4
RE: Why does the Prime use anti aliasing on text?
(07-08-2019 02:36 PM)TheLastMillennial Wrote:  I recently learned that the Prime uses anti aliasing on text and I am unsure why it's necessary. Could the text have been left alone? Why was anti aliasing chosen over subpixel rendering? Personally, I don't care that much for the anti aliasing, is there any way to reduce it, remove it, or turn it off?

Are you volunteering to make pixel perfect drawings of 35 thousand characters in a variety of sizes? Smile

Freetype2 is used for font rendering from a standard TTF font. Subpixel rendering is not used because it didn't really help (too small and low resolution of a screen) and increases memory use by 3x. Anti-aliasing is the wrong word here - the default freetype2 autohinter is in use.

Turning it off would make things unreadable, not better.

TW

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07-09-2019, 06:50 AM
Post: #5
RE: Why does the Prime use anti aliasing on text?
Hello,

> Why does the Prime use anti aliasing on text?

Because some "modern", "young" guy thinks that it's better...
Strangely enough, some other, let us say, more traditional, older (and therefore wiser, don't you thinkWink guy does not like it :-)

Guess who won on that one :-)

Plus, non anti-aliased (or should that be aliased?) font are way easier to draw! But guess who had to make the anti-aliased drawing function! Yep, the "traditional" guy! But it was fun to optimize...

Cyrille

Although I work for the HP calculator group, the views and opinions I post here are my own. I do not speak for HP.
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07-09-2019, 11:51 AM
Post: #6
RE: Why does the Prime use anti aliasing on text?
(07-09-2019 03:15 AM)Tim Wessman Wrote:  
(07-08-2019 02:36 PM)TheLastMillennial Wrote:  I recently learned that the Prime uses anti aliasing on text and I am unsure why it's necessary. Could the text have been left alone? Why was anti aliasing chosen over subpixel rendering? Personally, I don't care that much for the anti aliasing, is there any way to reduce it, remove it, or turn it off?

Are you volunteering to make pixel perfect drawings of 35 thousand characters in a variety of sizes? Smile

Freetype2 is used for font rendering from a standard TTF font. Subpixel rendering is not used because it didn't really help (too small and low resolution of a screen) and increases memory use by 3x. Anti-aliasing is the wrong word here - the default freetype2 autohinter is in use.

Turning it off would make things unreadable, not better.

I would rather turn Anti-aliasing off...
But I think the best choice is to let us decide whether to turn it off or on , so that we won't arguing with developers like you Big Grin
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07-09-2019, 12:07 PM
Post: #7
RE: Why does the Prime use anti aliasing on text?
HP used to make a calculator that supported custom fonts, you know. Wink
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07-09-2019, 01:23 PM
Post: #8
RE: Why does the Prime use anti aliasing on text?
(07-09-2019 12:07 PM)Dave Britten Wrote:  HP used to make a calculator that supported custom fonts, you know. Wink

Yes, but that model only supported the ascii character set (w/minor extensions for a few special characters), while the Prime supports many languages and associated character sets. Tim notes above there about 35000 characters...

--Bob Prosperi
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07-09-2019, 01:39 PM
Post: #9
RE: Why does the Prime use anti aliasing on text?
(07-09-2019 01:23 PM)rprosperi Wrote:  
(07-09-2019 12:07 PM)Dave Britten Wrote:  HP used to make a calculator that supported custom fonts, you know. Wink

Yes, but that model only supported the ascii character set (w/minor extensions for a few special characters), while the Prime supports many languages and associated character sets. Tim notes above there about 35000 characters...

NewRPL Is fully Unicode too, you just need a suitable font Wink
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07-09-2019, 08:27 PM
Post: #10
RE: Why does the Prime use anti aliasing on text?
(07-08-2019 04:34 PM)Joe Horn Wrote:  Pretend that you have to look at the following two screens all day, and read the fonts as displayed here. Both have unique benefits and drawbacks when compared with each other. But which one would annoy you the least at the end of a day of use?

[Image: MediumFont.png] [Image: MediumNewFont.png]

My personal opinion is that the dithered font is slightly BOLDER than the un-dithered font whose strokes are TOO THIN for long-term comfort. I can read the dithered font at a faster glance than the un-dithered font. Yes, the un-dithered font is "cleaner"... but that doesn't make it more readable. For me. Apparently opinions differ, which is fine. Please share yours.

Here's a comparison of what it could've looked like with subpixel rendering (left). I tried my best to match the fonts, but it's not exact. Note that you must view the image at a 1:1 pixel scale on a normally-oriented screen for the subpixel rendering effect to work.

[Image: ei7Lr3z.png] [Image: ScWX8Tx.png]
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07-10-2019, 01:41 AM (This post was last modified: 07-10-2019 01:46 AM by TravisE.)
Post: #11
RE: Why does the Prime use anti aliasing on text?
The effect of the subpixel rendering mockup isn't really going to come across on a forum like this unless you literally view the image directly on the HP Prime's screen. The monitor you're using to view it now won't necessarily match the Prime's display performance, contrast, DPI, resolution, or geometric subpixel layout, so trying to judge by screenshots here is likely to lead one to an inaccurate conclusion.

Jim Horn makes an interesting point. On my desktop Linux machine, I selected a particular Freetype hinting mode due to the fonts appearing bolder and easier to read rather than the one that was supposed to be most faithful to the font's shape. In the case of the Prime, I suspect I wouldn't have any complaint reading non-antialiased text, though I'd have to actually try it in order to say for sure. Bitmap fonts were never any trouble for me with “classic” monochrome calculators, but those had quite low DPI displays by today's standards. But the Prime's LCD does seem to be just low enough of a DPI that I agree that the antialiasing doesn't look particularly brilliant, either.

Getting rid of antialiasing would probably also require some careful hinting to avoid distorting font characters at such a low resolution, though. Back in the Windows 9x days, I believe I remember reading that Microsoft chose to design their default fonts and font rendering engine to optimize for more legible on-screen reading, at a possible expense of shape accuracy. Such an optimization would be important here. (As an interesting side note, I seem to remember that when they first introduced antialiased text, the system tended to apply it only to bold text and larger font sizes in the earlier versions of Windows for some reason, leaving smaller text without the smoothing. Perhaps at the time this was considered more legible.)
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07-10-2019, 01:48 AM
Post: #12
RE: Why does the Prime use anti aliasing on text?
Could always take it to the absolute extreme:

http://www.msarnoff.org/millitext/
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07-10-2019, 05:17 PM
Post: #13
RE: Why does the Prime use anti aliasing on text?
(07-10-2019 01:41 AM)TravisE Wrote:  Jim Horn makes an interesting point.

That would be *Joe* Horn - he's the Horn here who knows what he's talking about.
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07-10-2019, 05:26 PM
Post: #14
RE: Why does the Prime use anti aliasing on text?
(07-10-2019 05:17 PM)Jim Horn Wrote:  That would be *Joe* Horn - he's the Horn here who knows what he's talking about.

Whoops! Sorry, my mistake, defective memory. Big Grin (Didn't even realize we had both here, either!)
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