RAM Posted October 5, 2017 Share Posted October 5, 2017 Can't find the xex file for this one though, I'm sure I finished this one too. Oh well, doesn't matter now! 7 Quote Link to comment Share on other sites More sharing options...
VladR Posted October 5, 2017 Share Posted October 5, 2017 MF.gif Did this a few years ago on G2F, can't remember now if I posted it or not. I did a Star Trek one too, but can't find it now. Rastaconverter kind of killed off my enthusiasm for doing these pics! Falcon.xex This is an excellent image, especially because it doesn't have any typical color noise/interpolation there, just nice clean single-color lines, that would convert fine to a real-time 3D scenario (at 5 colors, though). This particular ship has too many circular subobjects for real-time 3D, however. Would you be able to convert some simpler spaceship / scout (something simple - like Raptor from Galactica) ? I've been chasing this thread for a long time for some suitable candidate spaceship, but most of them have too much dithered detail in them (as their goal is to get as many colors as possible - this is RastaConverter after all), while this one is nice and clean! I honestly believe that something less circular (more triangular) could run in real-time on A800 (like, 3-5 fps, but hey), with some texturing. I just realized, when looking at this picture, that you can add the "texturing" details simply during rasterizing without typically expensive texturing computations. Notice how the long rectangular middle section has long [single-color] lines along the edges. Once one has the edge equation computed, we just need to re-traverse it in screenspace (e.g. each scanline wouldn't have same ypos - like say in flatshading, but rather it would be the edge (just offset by 1 pixel for each new "scanline")) and change color of the pixel. Real simple, and no expensive texturing needed, but the effect is real strong. My apologies for derailing this thread, we could continue this discussion in the flatshading thread in the 8-bit programmer section. Quote Link to comment Share on other sites More sharing options...
emkay Posted October 5, 2017 Share Posted October 5, 2017 This is an excellent image, especially because it doesn't have any typical color noise/interpolation there,... It's in the right preparation of a picture. Somehow "6 colors" per scanline and slight changes of the colors over the vertical area could result in the best pictures(plus details) ... Here some picture to fill the rules for the thread emkay_basilika_err.xex 6 Quote Link to comment Share on other sites More sharing options...
a8isa1 Posted October 5, 2017 Share Posted October 5, 2017 (edited) Here's my exercise in strong dithering. I like the pictures, some more than others, but I don't know if anyone else will. All the files for this set are included at the end of this post. Unless, otherwise noted for all pictures I used LINE dithering with /dither_val=1.5 (or higher). Most of these pictures are still works in progress. A few just need more processing but most need a change of parameters for rastaconverter and/or source tweaking*. All these pictures are screen captures from Altirra-2.99-test10. My palette is a customization of an NTSC palette (see notes). I don't believe any of the pictures will work well for PAL output. Sorry, I don't have enough processing power on this laptop to do multiple conversions of the each picture. They look OK using any of Altirra's default NTSC presets. These are nearly completed but I guess they could stand as they are. The original photo of the first picture here demonstrates shallow depth of field, the bird and its reflection are in focus. Everything behind and in front of the bird is out of focus. I think strong LINE dithering manages to convey that. For these I think I know what needs to be done to improve them. For these I think I used LINE2 dithering with /dither_val=0.4 and /dither_rand greater than 1.0. They are completed. And, I'm not sure what to do with these. They have stalled in rastaconverter, in that norm.dist. is ticking over only at the 5th significant digit. They aren't very good as they are now. This last picture is actually a composite of two kinds of dithering. I ran rastaconverter twice, once with strong LINE dithering, once with JARVIS dithering with /dither_rand=1.5, I think. I don't recall what /dither_val numbers I used. I then used GNU gimp to mask out the bottom of the JARVIS dithered picture. By combining (I forget which layering option I used) the two pictures together the final picture has two kinds of dithering for the sky but only LINE dithering for the bottom of the picture. This picture was run through rastaconverter one last time but with all parameters at default and no dithering. The result wasn't what I was hoping I would see. I got the colors and the shadings I wanted in the clouds but it's all very busy. If you step back (way back) you can see the picture is there. However, on the laptop, as I sit here, whoa! Ugliness! *Notes Regarding my customized palette in Altirra, years ago I came across Atari's 800 Technical Service document that describes how to adjust the color trim pot. According to the procedure one turns the trim pot with the intent of making hues 1 and 15 look identical. Now, they never did actually look identical but they could be made to appear very close to the same. That's what I did with my 800 and years later with my XLs and year after then that I learned that though this might have been a workable field service solution it is far from ideal. Unfortunately, without any equipment or the know-how there was no way for me to restore my machines to their factory state. They sit now as I had adjusted them. So, what I did to Altirra's palette is what I think reproduces what the above procedure does to my real Atari. Under System-->Video-->Adjust Colors I set these as follows: Hue Start: -44 Hue Step: 25.7 Brightness: -12% ; these are three a personal preference Contrast: 99% ; slide won't settle on 100% Saturation: 28% These colors look very close to what I see on my real Ataris (adjusted as described above) More Notes: I can make up some note regarding how I preprocess pictures for Rasta conversions at a later date (if anyone wishes to see them). a8isa1_rastaconverter_pics_set_1.zip Edited October 5, 2017 by a8isa1 6 Quote Link to comment Share on other sites More sharing options...
emkay Posted October 5, 2017 Share Posted October 5, 2017 ... That BW Surfer picture shows good details. As it's mostly BW. Not sure, where this happens, but picture is using 12 colors. So it handles color changes, even if they were wrong / not needed... Where did it get "green" colors ? Actually, it needs a lot of preparations to assure Rastaconverter isn't throwing false colors in. This picture uses "real" 7 colors for the full image. which means 7 "grey" tones even in the single scanline. If it was possible to set the color changing values to an index, colors could be changed afterwards... emkay_mastani.xex 5 Quote Link to comment Share on other sites More sharing options...
a8isa1 Posted October 5, 2017 Share Posted October 5, 2017 That BW Surfer picture shows good details. As it's mostly BW. Not sure, where this happens, but picture is using 12 colors. So it handles color changes, even if they were wrong / not needed... Where did it get "green" colors ? Oh. Using a default palette I now see the green color. This was a conversion I did I think last year. After probably 3 dozen FAILs I decided a black & white picture ought to be very easy but I was wrong. False colors were and are a problem. I tried using Gray.act but this makes for many false colors when the XEX is run on an emulator with a full color palette or on a real machine. I thought I had eliminated them finally. I guess I was wrong. I'm not sure how to fix the problem. Quote Link to comment Share on other sites More sharing options...
emkay Posted October 5, 2017 Share Posted October 5, 2017 I'm not sure how to fix the problem. A real solution isn't easy. But to use the destination picture with some adjusted palette, allows to put the picture without any resizing or dithering... and some external tool that allows the needed pallete emkay_chun_bw.xex For creating a picture it is needed to keep the same palette during the whole progress. The resulting picture will always use the correct values then. Actually, in this one I had to redraw some parts, to keep some relevant details .... 5 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 5, 2017 Share Posted October 5, 2017 (edited) False greens where only grays should be is a long standing problem I suffer through. Sometimes I ignore them, other times I will adjust the contrast and brightness until other "grays" are picked by Rasta that don't look green. I am of course referring to when viewed on a real PAL Atari. I have no experience with Rasta yet on an NTSC machine. I'm rebuilding an NTSC machine now. I don't know if or when I'll start using other programs and tools to edit. Probably not until I start doing my own original art for Atari's again. Right now I just make the best conversions I can, strictly through Rastaconverter (except for some cropping and resizing I do with Infraview 64) of stuff I find on the web. Millennium Falcon. 31 colors. The lighter picture is the brightness of the original image. These images are for Stephen, and nothing to do with my comments above. MillenniumFalcon3.xex Falcon1.xex Edited October 5, 2017 by Gunstar 4 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 5, 2017 Share Posted October 5, 2017 False greens where only grays should be is a long standing problem I suffer through. Sometimes I ignore them, other times I will adjust the contrast and brightness until other "grays" are picked by Rasta that don't look green. I am of course referring to when viewed on a real PAL Atari. I have no experience with Rasta yet on an NTSC machine. I'm rebuilding an NTSC machine now. I don't know if or when I'll start using other programs and tools to edit. Probably not until I start doing my own original art for Atari's again. Right now I just make the best conversions I can, strictly through Rastaconverter (except for some cropping and resizing I do with Infraview 64) of stuff I find on the web. Millennium Falcon. 31 colors. The lighter picture is the brightness of the original image. These images are for Stephen, and nothing to do with my comments above. Odd with the green / grey thing. It seems Rasta Convertor suffers the same colour-blindness that I do, but in reverse 2 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 5, 2017 Share Posted October 5, 2017 Can't find the xex file for this one though, I'm sure I finished this one too. Oh well, doesn't matter now! 1701.gif Actually, these G2F images are encouraging me to move away from Rasta conversions and start doing real pixel art again. Though probably with graphic programs on the Atari, and not G2F so much. 1 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 5, 2017 Share Posted October 5, 2017 Actually, these G2F images are encouraging me to move away from Rasta conversions and start doing real pixel art again. Though probably with graphic programs on the Atari, and not G2F so much. I would, if I had skills beyond creating a solid box on the Atari, or a stick figure IRL. Looking forward to any new content though. Quote Link to comment Share on other sites More sharing options...
adam242 Posted October 5, 2017 Share Posted October 5, 2017 Here's my exercise in strong dithering. I like the pictures, some more than others, but I don't know if anyone else will. a8isa1_sunset3_screenshot.png Stunning! How many individual colors is this one? Quote Link to comment Share on other sites More sharing options...
a8isa1 Posted October 5, 2017 Share Posted October 5, 2017 Stunning! How many individual colors is this one? output.png has 76 colors but I don't know if all colors make it onto the Atari's screen. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 6, 2017 Share Posted October 6, 2017 Nasa concept ship. Dithered, 40 colors. Nebulon Frigate. Dithered version. 54 colors. Space Ranger V7. 80 colors. Royal Cruiser. 60 colors. Bird of Prey. 57 colors. NasaConcept2.xex NebulonFrigate2d.xex SpaceRangerV7.xex RoyalCruiser.xex BirdofPrey1.xex 5 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted October 6, 2017 Share Posted October 6, 2017 emkay_mastani.png emkay_chun_bw.png In most cases, grayscale pictures will turn out better using GTIA 16 luminance mode. GTIA does better with less detail of course, so close ups like the Mastini picture generally turn out better. The Chun Li picture loses some details (particularly the swirling patterns off to the side of her) retained in the raster-converter version. But the amount of colors available in the GTIA mode tend to cover over any loss of details because of the smooth transition between luminances and still can produce a good conversion of the piece. 1 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted October 6, 2017 Share Posted October 6, 2017 From there, you have the option to change the color value -- which I think usually looks better. 2 Quote Link to comment Share on other sites More sharing options...
emkay Posted October 6, 2017 Share Posted October 6, 2017 (edited) In most cases, grayscale pictures will turn out better using GTIA 16 luminance mode. That doesn't hit the point of the conversions I'd still prefer the Rasta pictures for the details, as your Chun-Li picture even is reduced at all. The point is that Rastaconverter pictures suffer by implemented wrong colors BY the used importing routines, that even cause calculations with wrong colors that weren't needed at all. AND contrary to the mode 9 pictures, the rasta pictures COULD get the fitting colors, IF it was possible to put the colors as they were, not as a neutral conversion tool suggests. The Atari has 16 colors and 8 brightness steps per definition. Those "eventually" fitting colors by any palette were not real. It IS possible, due to the raw color adjustments, to interchange every color with another ... Edited October 6, 2017 by emkay 1 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted October 6, 2017 Share Posted October 6, 2017 (edited) That doesn't hit the point of the conversions I's still prefer the Rasta pictures for the details, as your Chun-Li picture even is reduced at all. The point is that Rastaconverter pictures suffer by implemented wrong colors BY the used importing routines, that even cause calculations with wrong colors that weren't needed at all. AND contrary to the mode 9 pictures, the rasta pictures COULD get the fitting colors, IF it was possible to put the colors as they were, not as a neutral conversion tool suggests. The Atari has 16 colors and 8 brightness step per definition. Those "eventually" fitting colors by any palette were not real. It IS possible, due to the raw color adjustments, to interchange every color with another ... Yes, I know... I wasn't answering anything about the conversational part -- which is why I didn't quote any of your comments in my replies. I just think it's interesting to get a comparison between the grayscale raster-converter images and the same images done in the lower-resolution GTIA mode. Edited October 6, 2017 by MrFish 1 Quote Link to comment Share on other sites More sharing options...
emkay Posted October 6, 2017 Share Posted October 6, 2017 (edited) Yes, I know... I wasn't answering anything about the conversational part -- which is why I didn't quote any of your comments in my replies. I just think it's interesting to get a comparison between the grayscale raster-converter images and the same images done in the lower-resolution GTIA mode. Nah.... particular the "Mastani" picture, could be enhanced to all colors (256 on the Atari) , when using G2F... some older examples.... or just this... Sorry for the derailing... And now back to topic Edited October 6, 2017 by emkay 1 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted October 6, 2017 Share Posted October 6, 2017 (edited) Nah.... particular the "Mastani" picture, could be enhanced to all colors (256 on the Atari) , when using G2F... Definitely much more color could be added using PMG's, but you're dreaming about "all 256" in any practical application with the Mastini photo; nothing you show here is even close to 256 colors either -- not to mention half the examples show sloppy use of PMG's. Edited October 6, 2017 by MrFish Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 6, 2017 Share Posted October 6, 2017 Yes, I know... I wasn't answering anything about the conversational part -- which is why I didn't quote any of your comments in my replies. I just think it's interesting to get a comparison between the grayscale raster-converter images and the same images done in the lower-resolution GTIA mode. I need to find the GTIA version of this. I was surprised at how nice the medium-res conversion turned out. 1 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted October 6, 2017 Share Posted October 6, 2017 I need to find the GTIA version of this. I was surprised at how nice the medium-res conversion turned out. preview1.png I'm guessing that would be an example of an image that wouldn't turn out too well in GTIA mode because of the high level of detail (where all the blocks are bunched together in the upper-left) and lack of luminance variation throughout. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 8, 2017 Share Posted October 8, 2017 (edited) DP. Edited October 8, 2017 by Gunstar Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 8, 2017 Share Posted October 8, 2017 (edited) Final Descent. 50 colors. Bespin. 29 colors. Cloud City. 53 colors. FinalDecscent.xex Bespin.xex CloudCity.xex Edited October 8, 2017 by Gunstar 3 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 8, 2017 Share Posted October 8, 2017 So - I have every file from this thread saved, and am making sure to keep up with it. Can comsone PM me a way to keep this up to date for everyone? Not sure - do a torrent, a GITHub repo? ZIP file is 7.36MB, extracted, it is 15.1MB, 736 files. 8 Quote Link to comment Share on other sites More sharing options...
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