Dithering in 16-Color SCI Games

Charles · Post by **Charles** » Sat Dec 19, 2009 7:10 pm

This undithering is really awesome. I fully expected you guys to eventually code support for not dithering the backgrounds, but that you're also actively trying to undither the sprites is incredible. Just one question about that, is there a setting where I can disable sprite undithering but still enable background non-dithering?

m_kiewitz · Post by **m_kiewitz** » Sun Dec 20, 2009 9:58 am

Charles wrote:Just one question about that, is there a setting where I can disable sprite undithering but still enable background non-dithering?

There is currently none.

lazylazyjoe · Post by **lazylazyjoe** » Mon Dec 21, 2009 5:40 pm

I had this very conversation last year on this board with a guy, musicallyinspired, who was making a 16 color fan-made sci0 remake of KQ2. I was talking about how the dithering and filtering (on freesci of course) made the games look nicer, but he told me that it altered the way that he designed the game and didn't like it. So, this definitely isn't what the original artists intended. Just another interpretation, like fin said.

I still think it's awesome though. Of course, in it's day 4 bit color dithering was a pretty cool tech too. Did Sierra invent this, or did they license it?

LogicDeLuxe · Post by **LogicDeLuxe** » Mon Dec 21, 2009 9:09 pm

lazylazyjoe wrote:So, this definitely isn't what the original artists intended. Just another interpretation, like fin said.

Just because one artist says so doesn't mean that this is valid for everyone.

fingolfin · Post by **fingolfin** » Mon Dec 21, 2009 9:47 pm

LogicDeLuxe wrote:
lazylazyjoe wrote:So, this definitely isn't what the original artists intended. Just another interpretation, like fin said.
Just because one artist says so doesn't mean that this is valid for everyone.

In particular one artist who was not one of the original artists, so it's even less relevant -- his opinion is his alone, and does not say anything at all about what those folks thought over a decade ago

.

m_kiewitz · Post by **m_kiewitz** » Mon Dec 21, 2009 10:04 pm

fingolfin wrote:
LogicDeLuxe wrote:
lazylazyjoe wrote:So, this definitely isn't what the original artists intended. Just another interpretation, like fin said.
Just because one artist says so doesn't mean that this is valid for everyone.
In particular one artist who was not one of the original artists, so it's even less relevant

Especially because this one definitely did not use the original sierra development utilities at all. If sierra would have wanted to really "just" be 16 colors, then they wouldnt have done such a hassle. Sierra wanted definitely to be able to offer more than 16 colors. And even the dithered pictures look really great, I don't remember any game that nearly looked that great on EGA.

HelixNRG · Post by **HelixNRG** » Tue Dec 22, 2009 5:01 am

Especially because this one definitely did not use the original sierra development utilities at all. If sierra would have wanted to really "just" be 16 colors, then they wouldnt have done such a hassle. Sierra wanted definitely to be able to offer more than 16 colors. And even the dithered pictures look really great, I don't remember any game that nearly looked that great on EGA.[/quote]

But if Sierra REALLY wanted to offer more than 16 colours, why didn't the Amiga versions of the SCI0 games, capable of displaying 32 colours, use these supposedly extra defined colours?

- Alex

Seldon · Post by **Seldon** » Tue Dec 22, 2009 6:11 am

Actually, I don't care what Sierra wanted me to see. I care for what looks nice to ME. Undithering is nice for large, textureless areas of same color, but fails for small details or gradients (color changes are too sharp). That's why I prefer original version. Undithering would be great here and there, but for now (if ever) the algorithm is not smart enough to determine where it's safe/desireble to apply it.
However, I would gladly see the use of undithering controlled by human through some "undithering maps" created for each game individually, but it's too much work to tag all artwork in all the games, and probably (due to personal tastes) most of peers would still be unsatisfied.

lazylazyjoe · Post by **lazylazyjoe** » Tue Dec 22, 2009 7:53 am

That's art in general. It is interpretive. Everyone sees something different. It comes down to what you get out of it, not what you were intended to get. I only brought up my past conversation because we were talking about the same thing. I was actually expecting him to chime in and put his thoughts in.
When these games came out and I played them, I was way too young to know anything technical about them; but the original look is still in my mind and that's what I think of when I recall the game. Don't get me wrong though, I think this process is cool, and I have since I saw in on FreeSci a while back. ( Has anyone done a comparison of FreeSci and Scummvm for their undithering ? )

I'm always for improving art, be it in music, movies, games so long as the original is left intact and available also. I like to always have the original to compare it to any future remakes, remasters, or updating.
For example, I'm a megadeth fan and he recently remastered/mixed all his albums. I went and got most of the new albums, but kept, and still listen to, the originals. As better as the remastering makes it sound, I like to hear what I heard when I first bought the CD (or cassette..) I'm sure it's the same for Star Wars or Disney fans or colorized movies.

m_kiewitz · Post by **m_kiewitz** » Tue Dec 22, 2009 10:52 am

HelixNRG wrote:But if Sierra REALLY wanted to offer more than 16 colours, why didn't the Amiga versions of the SCI0 games, capable of displaying 32 colours, use these supposedly extra defined colours?

32 colors is not enough.
If amiga would have been capable of displaying 256 colors, I bet they would have done so.

Seldon · Post by **Seldon** » Tue Dec 22, 2009 11:39 am

m_kiewitz wrote: 32 colors is not enough.
If amiga would have been capable of displaying 256 colors, I bet they would have done so.

Why 256? They could still use 32-color dithering, which would look much better than using only 16 colors.
I suppose they didn't want to put effort into testing and finetuning such improvement (as implementing would be pretty straightforward). Maybe they expected glitches we observe with undithering now and preferred to deliver inferior but tested content. Though these are only my hypotheses based on suppositions

md5 · Post by **md5** » Tue Dec 22, 2009 1:37 pm

lazylazyjoe wrote:( Has anyone done a comparison of FreeSci and Scummvm for their undithering ? )

The undithering algorithm in ScummVM is superior, as it processes both backgrounds and sprites, whereas in FreeSCI only backgrounds are processed

Seldon · Post by **Seldon** » Tue Dec 22, 2009 1:54 pm

md5 wrote:The undithering algorithm in ScummVM is superior, as it processes both backgrounds and sprites, whereas in FreeSCI only backgrounds are processed

Does it process each component of the scene individually or is it applied on fully rendered scene?

m_kiewitz · Post by **m_kiewitz** » Tue Dec 22, 2009 7:36 pm

Seldon wrote:
m_kiewitz wrote: 32 colors is not enough.
If amiga would have been capable of displaying 256 colors, I bet they would have done so.
Why 256?

Because dithered sci pictures are able to contain almost up to 256 colors in total. It's the EGA palette (16 colors) and all those colors mixed with each other.

They could still use 32-color dithering, which would look much better than using only 16 colors.

In theory yes, but as the pictures may contain much more colors in total this wouldn't have been easy at all. Also it would have looked awkhard, because after showing 16 mixed "undithered" colors they would have needed to switch back to dithered drawing for the remaining mixed colors.

Maybe they expected glitches we observe with undithering now and preferred to deliver inferior but tested content.

We are talking about 2 things here. The background graphics work in all cases, because those were meant to be that way. The "glitches" are within the view/cel undithering and that's a completely different story. views/cels really only contain 16 colors and are already dithered, so undithering those requires some special techniques. Most sierra games don't require this at all and even the ones that "require" it only require it for a few views/cels. In our sci those views/cels are getting detected, sierra of course wouldn't have needed to do this at all. They could have changed the views/cels directly. So it's only complicated in our case. Of course we could also "just" offer some patches for the games and implement those manually.

m_kiewitz · Post by **m_kiewitz** » Tue Dec 22, 2009 7:40 pm

Seldon wrote:
md5 wrote:The undithering algorithm in ScummVM is superior, as it processes both backgrounds and sprites, whereas in FreeSCI only backgrounds are processed
Does it process each component of the scene individually or is it applied on fully rendered scene?

It's a separated process. First the background picture is shown and sci script request that views/cels are drawn on top of that. Those get detected as being part of the background and getting undithered and drawn on top.

Background and view/cel undithering is completely different. Actually background "undithering" means "not doing a dithering run on the background" and views/cels "undithering" means really detecting dithered pixel combinations and replacing those with the correct mixed color.