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Images generated by RastaConverter

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Here is a great example of why proper pre-processing is important. Below is the result of a 100 million evaluation session using knoll dithering. I will post an updated version much later tonight once I have access to my machine with Photoshop. When I stopped this, the Normal Distribution 9.947.

 

post-650-0-10034000-1369161978_thumb.png

output.xex

OK - as promised, here are the results (not as good as I had hoped). The image on the left, is using no dither, 1000 solutions, 45 million iterations and an image mask of my entire car. This made the red car above it have too little detail. The image on the right is also no dither, 1000 solutions, 63 million iterations, and no image mask. Before running Rasta Convertor, I trimmed the image in Photoshop, converted it to a 256-colour image using the Altirra.act palette, and applied a 75% diffusion dither to the image.

post-650-0-02218000-1369193840_thumb.pngpost-650-0-79576300-1369193840_thumb.png

 

Here are the source images

post-650-0-73956400-1369193842_thumb.pngpost-650-0-37238800-1369193843_thumb.png

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OK - as promised, here are the results (not as good as I had hoped). The image on the left, is using no dither, 1000 solutions, 45 million iterations and an image mask of my entire car. This made the red car above it have too little detail. The image on the right is also no dither, 1000 solutions, 63 million iterations, and no image mask. Before running Rasta Convertor, I trimmed the image in Photoshop, converted it to a 256-colour image using the Altirra.act palette, and applied a 75% diffusion dither to the image.

post-650-0-02218000-1369193840_thumb.pngpost-650-0-79576300-1369193840_thumb.png

 

Here are the source images

post-650-0-73956400-1369193842_thumb.pngpost-650-0-37238800-1369193843_thumb.png

 

You need to let Dither run in the rasta proram, it makes a huge difference I have found. The Knoll method is slower but gives much better results. The car photo you converted is nice though.

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Two more images of my all time favourite car - the wonderful 1970 Plymouth Superbird.

 

Specs: 80 million iterations, knoll dithering, 1000 solutions, normal distance 1.8 (lowest ever). Source image was first converted to 256 colours using the Altirra.act palette and resized to 320*240 in Photoshop, using "Bicubic smoother". No dithering was applied to the source image.

post-650-0-66176400-1369276348_thumb.pngpost-650-0-84836400-1369276311_thumb.pngWhiteSuperbird.xex

 

Specs: 207 million iterations, knoll dithering, 1000 solutions, normal distance 10.278. Nothing was done to the source image - it was a 640X480 24-bit jpeg. The Atari image has 37 distinct colours.

post-650-0-04443100-1369276358_thumb.pngpost-650-0-85295200-1369275641_thumb.pngBlueSuperbird.xex

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That's some great results - the pics suit really well since the angles suit the off-ratio pixels of the graphics mode.

 

A hack to do interlaced (ie proper 480i) RastaConverter pics would be something worthwhile possibly.

Edited by Rybags
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Thanks. I got lucky with the photos I chose - I did search for a while to find something I thought would process nicely.

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PIcture I used during testing and that I let run for several days on my Atom HTPC before giving up at ~950M iterations.

 

post-16457-0-49399500-1369288916_thumb.pngfeena.xex

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Before running Rasta Convertor, I trimmed the image in Photoshop, converted it to a 256-colour image using the Altirra.act palette, and applied a 75% diffusion dither to the image.

 

It seems to me that by pre-reducing the palette, you would be discarding the extra color resolution that the dithering algorithm needs to work effectively in the first place, since the entire point of dithering is to simulate more colors than are actually present in the image.

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Two more images of my all time favourite car - the wonderful 1970 Plymouth Superbird.

 

Specs: 80 million iterations, knoll dithering, 1000 solutions, normal distance 1.8 (lowest ever). Source image was first converted to 256 colours using the Altirra.act palette and resized to 320*240 in Photoshop, using "Bicubic smoother". No dithering was applied to the source image.

post-650-0-66176400-1369276348_thumb.pngpost-650-0-84836400-1369276311_thumb.pngWhiteSuperbird.xex

 

Specs: 207 million iterations, knoll dithering, 1000 solutions, normal distance 10.278. Nothing was done to the source image - it was a 640X480 24-bit jpeg. The Atari image has 37 distinct colours.

post-650-0-04443100-1369276358_thumb.pngpost-650-0-85295200-1369275641_thumb.pngBlueSuperbird.xex

 

I guess I'm not quite appreciating this topic properly. When I run the output.png-src.png through Irfanview reducing colors to 37 using Floyd-stienbeg dithering it seems to give me a better picture. Am I just bias for PC imaging software using that dithering technique?

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I guess I'm not quite appreciating this topic properly. When I run the output.png-src.png through Irfanview reducing colors to 37 using Floyd-stienbeg dithering it seems to give me a better picture. Am I just bias for PC imaging software using that dithering technique?

The Atari doesn't have the ability to put any colour at any pixel, so that is not a fair comparison.

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It seems to me that by pre-reducing the palette, you would be discarding the extra color resolution that the dithering algorithm needs to work effectively in the first place, since the entire point of dithering is to simulate more colors than are actually present in the image.

Photoshop does the dithering as it is reducing the colours, so it uses the full palette.

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Ah, that makes sense. I thought the dithering was happening in RastaConverter.

 

In that case, it would probably be useful if someone created a 128-color Atari palette, since the full 256 colors are only available in the GTIA modes.

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24-hour run on the Atom, 300M iterations, PAL palette, noborder, 10K solutions. Also, I think I'm going to go back to Floyd-Steinberg dithering as Knoll is too much like ordered and produces dirtier edges.

 

post-16457-0-45598900-1369372377_thumb.pngsaber.xex

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Just did a little contribution to this thread.

 

Original: post-3781-0-89476600-1369387153_thumb.png

 

Result: post-3781-0-65762100-1369387343_thumb.png FCU15-03-2013.xex

 

About 1.2 million Iterations with the new multi thread version. /floyd and /noborder

 

Don't know why I get those ugly lines ont the left and right border, but the rest seems to be well done.

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Finally I found some time to test this too, so this is only proof of that I am using it now, quality is not too good, still have to test all the settings:

post-21666-0-82021300-1369404188_thumb.png

 

There´s the executable: fc.xex

 

And here´s my attempt to keep the cores busy, but I fail:

post-21666-0-51714600-1369404102_thumb.jpg

Edited by skr

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Odd that you are not pegging the CPU. I have not tried running multiple instances, but when running phaeron's updated version with the "/threads=#" switch, it does scale properly (1 through 4 uses 25, 50, 75, 100% on my quad-core box).

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phaeron´s version?

 

Honestly: This has become really complicated. I´ve entered the thread late and am still confused. Too much different information spread over too many pages. For now I am happy to be able to create .xex pictures with what I assume was the latest version posted here.

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phaeron´s version?

 

Honestly: This has become really complicated. I´ve entered the thread late and am still confused. Too much different information spread over too many pages. For now I am happy to be able to create .xex pictures with what I assume was the latest version posted here.

 

Well,

 

you cannot find the newest version in this topic - because it is in the Quantizator topic here:

http://atariage.com/forums/topic/156160-quantizator/page__st__825#entry2756887

 

-Andreas Koch.

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About 1.2 million Iterations with the new multi thread version. /floyd and /noborder

 

Don't know why I get those ugly lines ont the left and right border, but the rest seems to be well done.

 

If you don't have clean black borders, then you are not using the latest version. The /noborders option was removed several versions ago. ilmenit's version 5.1 is here. phaeron's threaded version is here.

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