Images generated by RastaConverter

[+MrFish]

The one I use is 0.0.2.1 dated 2013. I did download another file from this thread not too long ago, and I thought it might be a more recent version, I never found out though, as it screwed everything up and I had to do a system restore on my PC and then re-install the version I have now to get things working again!

 

Version 0.0.2.1 is actually for the GUI front end. I was talking about the RastaConverter program itself, which doesn't seem to carry version information in the "Properties" -- although the person who posted the version I just downloaded put some version information in the filename.

 

Anyway, I was able to download the latest a few pages back in this thread and it wasn't what I was using. I thought my rate and CPU usage seemed low with the version I was using.

 

So now I have to figure out if I want to re-evaluate or continue evaluation from where the older version left off.

Edited October 19, 2017 by MrFish

[Gunstar]

 

Version 0.0.2.1 is actually for the GUI front end. I was talking about the RastaConverter program itself, which doesn't seem to carry version information in the "Properties" -- although the person who posted the version I just downloaded put some version information in the filename.

 

Anyway, I was able to download the latest a few pages back in this thread and it wasn't what I was using. I thought my rate and CPU usage seemed low with the version I was using.

 

So now I have to figure out if I want to re-evaluate or continue evaluation from where the older version left off.

Can you post the latest version you just got, so I can compare with what I am using?

[+MrFish]

It's here.

[a8isa1]

 

 

Certainly if you do not use the targeted palette in the emulator then you won't see the same thing as shown below.

So targeting laoo.act, for example, isn't a selectable palette in Altirra's presets (can you load it anywhere?) but could be loaded in A800Win(PLus).

 

OK I understand that there are different palettes and that one should use use the same palette in emulators as that used for the conversions. What I don't understand is why there are several palettes. Does each palette have a specific purpose?

 

I've explained in an earlier post why I have customized my palette in Altirra. It's an attempt to match the colors presented in Altirra with my real Ataris which years ago I adjusted as per an 800 technical service note I once read. I don't really have a way to put the Ataris back to factory settings so I just leave them.

 

In many of my strong dithering experiments with rastaconverter I used this customized palette. For others I used AuthenticNTSC.act. Is there an ideal palette I should be using for, for intent of viewing the pictures on my NTSC 800XL?

Edited October 19, 2017 by a8isa1

[Wrathchild]

From my own experimenting, e.g. in relation to the video conversions, I would say AuthenticNTSC and OlivierPAL are my general go-to's. As many have pointed out over the years though, different displays exhibit their own quirks and the same A8 hardware on one doesn't necessarily produce the same output as another so at the end of the day it's what you're happy with. In the last post it was a little surprising that the output.png and 'copy to clipboard' from Altirra had minor differences.

 

Sometimes it also seems a wise thing to do to setup the chosen A8 palette within an art package and then get that to recolour the original image to that.
It does seem that a predistance in rastaconverter of ciede followed by distance of yuv runs ok, showing the importance of that initial target.

[Gunstar]

Natural, 70 colors.

Natural.xex

[Gunstar]

Emerald Forest. 63 colors.

Desert Tower. 37 colors.

Horseshoe Bend. 59 colors.

Summer Cottage. 74 colors.

EmeraldForest.xex

DesertTower.xex

HorseshoeBend.xex

SummerCottage.xex

Edited October 24, 2017 by Gunstar

[Gunstar]

From my own experimenting, e.g. in relation to the video conversions, I would say AuthenticNTSC and OlivierPAL are my general go-to's. As many have pointed out over the years though, different displays exhibit their own quirks and the same A8 hardware on one doesn't necessarily produce the same output as another so at the end of the day it's what you're happy with. In the last post it was a little surprising that the output.png and 'copy to clipboard' from Altirra had minor differences.

 

Sometimes it also seems a wise thing to do to setup the chosen A8 palette within an art package and then get that to recolour the original image to that.

It does seem that a predistance in rastaconverter of ciede followed by distance of yuv runs ok, showing the importance of that initial target.

Early on I experimented with using Timanthes and recoloring to a chosen A8 pallette, the results were less than desirable in my experiences, making everything more pixelated, like extremely dense dithering. Maybe I need to try a different art package?

 

After much more extensive attempts with other palettes, Altirra is still my go-to for PAL, it looks the best on my PAL 1200XL, much more vibrant color use than any other pallette. When I do NTSC, I do use the AuthenticNTSC, and of course when viewed on my PAL system, colors can be unusual looking, I can only assume they look closer to the PAL version if viewed on an NTSC machine. But then, it's my only option ATM. But as you say, and I have said below, different dislays are. well, different. All one can do is use what looks best on their display, unless you have multiple NTSC and PAL systems and multiple types of monitors.

Edited October 24, 2017 by Gunstar

[Gunstar]

Emerald Forest. 63 colors.

Desert Tower. 37 colors.

Horseshoe Bend. 59 colors.

Summer Cottage. 74 colors.

These are a few that I attempted over and over, and was never satisfied with the results, but these are the best versions, and after time away and a fresh look, I think they are still worth releasing, considering the A8's limitations. They're still brilliant graphic images to see on an Atari.

Edited October 24, 2017 by Gunstar

[a8isa1]

These are a few that I attempted over and over, and was never satisfied with the results, but these are the best versions, and after time away and a fresh look, I think they are still worth releasing, considering the A8's limitations. They're still brilliant graphic images to see on an Atari.

Great pics

 

That "emerald forest" pic has been through rastaconverter here about 3 dozen times. Every time I get close I get bands that ruin the picture.

 

I still don't know how you manage your balance of colors.

[Gunstar]

Great pics

 

That "emerald forest" pic has been through rastaconverter here about 3 dozen times. Every time I get close I get bands that ruin the picture.

 

I still don't know how you manage your balance of colors.

I was adjusting to catch more of the "misty" atmosphere, and that's what I got. I've got one with better color, and it looks a bit misty-er but too much DLI color-banding. I'm not sure if that's what you are referring too, or if the color bands you mean are what I refer to at the line-errors that are caused by Rasta's algorithm stumbling over itself while climbing up hill...

Edited October 24, 2017 by Gunstar

[+wood_jl]

Man, this thread is really incredible, and rewarding to long-time A8 fans. I know youngsters or non-computer folk wouldn't be impressed, but I can't believe what I'm seeing on my Atari screen! Bravo!

[a8isa1]

I was adjusting to catch more of the "misty" atmosphere, and that's what I got. I've got one with better color, and it looks a bit misty-er but too much DLI color-banding. I'm not sure if that's what you are referring too, or if the color bands you mean are what I refer to at the line-errors that are caused by Rasta's algorithm stumbling over itself while climbing up hill...

The banding are areas that would normally have dark shadows and forground colors but instead look as if someone painted stain in a complete band, horizontally.

 

I might have the project still on file...

 

[EDIT]

Looks as though I had restarted the conversion but I can still show the banding.

 

Here is output.png. Other than needing more processing it's pretty clean.

 

This is a screenshot with my palette color changes (i.e. palette used for the conversion). One band is clear to see. The second one is less visible.

 

and here is the same screenshot using the default NTSC XL palette. The banding gets exaggerated thus helps demonstrate what I'm talking about. It looks as if a brush dragged gray stain across the picture.

Edited October 24, 2017 by a8isa1

[Gunstar]

The banding are areas that would normally have dark shadows and forground colors but instead looks like someone painted stain in a complete band, horizontally.

 

I might have the project still on file...

That has to do with the DLI's (Display List Interrupts) that are used, and what is happening is in those dark areas Rastaconverter is using the darkest luminance of a color instead of reverting to black. The only thing I have found to counter this is simply raising the contrast until all those areas become pure black. It really what I think is a problem with the Atari's built-in color palette; the darkest luminance on every color should have been darker or true black, The Atari's palette should have been set to have one lighter, almost white, luminance for each color and one darker, black or virtually black color. It's like the gray scale colors of the Atari are slightly higher contrast (one of 8/16 luminances) than the colors.

[a8isa1]

That has to do with the DLI's (Display List Interrupts) that are used, and what is happening is in those dark areas Rastaconverter is using the darkest luminance of a color instead of reverting to black. The only thing I have found to counter this is simply raising the contrast until all those areas become pure black. It really what I think is a problem with the Atari's built-in color palette; the darkest luminance on every color should have been darker or true black, The Atari's palette should have been set to have one lighter, almost white, luminance for each color and one darker, black or virtually black color. It's like the gray scale colors of the Atari are slightly higher contrast (one of 8/16 luminances) than the colors.

I don't know the structure of a palette file. Could we just substitute an absolute zero for all hues with 0 value luma in the palette file?

 

I have tweaked palette that essentially raises the black threshold and lowers the brightness to compensate but I use it only for processing. The tweak is too exaggerated to use on this picture.

Edited October 24, 2017 by a8isa1

[Gunstar]

I don't know the structure of a palette file. Could we just substitute an absolute zero for all hues with 0 value luma in the palette file?

 

I have tweaked palette that essentially raises the black threshold and lowers the brightness to compensate but I use it only for processing. The tweak is too exaggerated to use on this picture.

I see, well, I was battling banding like you on Emerald Forest, but I got about 80% knocked out, but I was also trying to still capture grays in the background, blending with the greens in an attempt to capture the misty look of the source image. Your versions actually achieve what I was attempting better than mine, but for the banding.

Edited October 24, 2017 by Gunstar

[Gunstar]

Sorry, I missed the part about substituting all the darkest hues for black, I suppose someone who knows how to make the Atari palette files (.act's) could tell you. If it could be done, I think results could be drastically improved! But it may be something that has to be done in the actual Rastaconverter program. I think a palette change would only work with .png's and maybe on the emulators set with the same palette. when viewed on a real Atari, I think the Atari would just "translate" all the blacks back to the darkest luminance of each color. In which case we would only be hiding the banding from ourselves until we viewed the .xex on a real Atari. A step in the wrong direction, definitely.

Edited October 25, 2017 by Gunstar

[Rybags]

Modifying the .pal file that RC uses won't help. If you had entries $10,$20,$30 etc equal to RGB 000 then all it's doing is presenting more options for areas that are black or very near to it. Whether it'd choose colour 0 for black every time, who knows? If it chose the other values then the picture would be all wrong on the real Atari.

 

What would be needed is to do pre-processing of the picture. It might be hard. You'd want to boost overall saturation of any colour above luma equivalent to 2 but almost eliminate saturation on lumas below 2.

[Gunstar]

Misty Park. 45 colors.

MistyPark.xex

[Gunstar]

The End Of Green. 47 colors.

EndOfGreen.xex

[Gunstar]

Crystal Sunset. 76 colors.

 

Glacial Moon. 42 colors.

CrystalSunset.xex

GlacialMoon.xex

[phaeron]

One possible fix for the black issue would be to generate a palette with narrowed range to represent blacker-than-black and whiter-than-white, i.e. black at $40 and white at $BF, and apply the same transform to the image. It's a simple 50% contrast reduction around 50% gray. This would prevent the overshoot from chroma from being clamped and thus allow the color matching algorithm to see more of the difference between true black and saturated black. Since the palette is already clamped to 0-255, you can't do this by transforming the existing palette -- it has to be regenerated and reexported.

 

On the other hand, if you simply want to avoid certain colors being used, you could try editing those colors in the palette to some obnoxious color not in your image (hot pink), raising the error for those colors unacceptably high for the color matcher.

[Gunstar]

Modifying the .pal file that RC uses won't help. If you had entries $10,$20,$30 etc equal to RGB 000 then all it's doing is presenting more options for areas that are black or very near to it. Whether it'd choose colour 0 for black every time, who knows? If it chose the other values then the picture would be all wrong on the real Atari.

 

What would be needed is to do pre-processing of the picture. It might be hard. You'd want to boost overall saturation of any colour above luma equivalent to 2 but almost eliminate saturation on lumas below 2.

If only the developers would take up the Rastaconverter torch again with a new version that could add such options directly instead of having to do pre-processing in other programs. Adding in a basic editor too, or maybe not so basic. Anyway, all that turns fun into work, something I'm not going to worry about until I start converting my own art work to the Atari (physical art, not digital, for digital art I start with an Atari).

[+StaxX28]

Hi

 

Again, some games title screens:

 

StaxX_BlinkysScarySchool.xex StaxX_Commando.xex

 

StaxX_PinkPanther.xex StaxX_Warhawk.xex

 

as usual, all pics were captured from a real PAL HW

[Gunstar]

These are fantastic! It's time to swap out title screens for Commando on the A8! I assume these are C64 sources? How many colors, on average, did Rastaconverter add to the original 16?