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Posted: Sat Jan 19, 2013 12:50 pm
by Stef
I'm looking for a image software which is able to take whatever image as input and optimize it for RGB333 display... I searched for severals hours now and cannot find anything, that's just crazy ! Does that actually exists ???
I do not speak about tools which just reduce colors number by clearing lower bits but tools which can actually use dithering to optimize the final RGB333 rendering.

Posted: Sat Jan 19, 2013 1:32 pm
by Ti_
Stef wrote: Does that actually exists ???
I know only one.
"Image to Sega"
It's doesn't clear 3bits, but use other simple method.

Posted: Sat Jan 19, 2013 3:18 pm
by bastien
You can use the xicolor dither plugin for photoshop paintshop pro or gimp.
The plugin name is ximagic

Posted: Sat Jan 19, 2013 4:41 pm
by Stef
Thanks for your fast replies !

The first tool can be useful as it can convert any images (without the usual 16 colors restriction) to genesis color image but still it is not able to do color quantization and optimization.

The later one seems to be able to do what exactly i want but i do not have photoshop, i will try some free alternatives which support photoshop plugin :)

Thanks again guys !

Posted: Sat Jan 19, 2013 4:53 pm
by sega16
You can use my direct color converter. First you convert the image to direct color and convert it back to png then the outputted png will have only genesis colors. http://sega16.x10.mx/directcolor.html

Posted: Sat Jan 19, 2013 6:57 pm
by Stef
Well i tried all solutions and... all failed X'D

XiColor can optimize images for RGB333 *but* it can't reduce colors at the same time (for instance if you want to reduce to 16 colors only).
So if you convert your base image to RGB333 you can end up with an image with 70 colors for instance. Then if you try to reduce the number of colors to 16 after the first operation, it will reintroduce new colors outside the RGB333 range :-(
It would be nice to choose at same time the color range (RGB333) and maximum color count but XiColor is not able to do that.

sega16>Thanks :) I tried your directcolor tool but again can't get what i want : i used the i3 switch as i want to convert for genesis palette but resulting images do not fit in the RGB333 space but in RGB666 (i can have color as #D86448 for instance).
I also want to specify the number of maximum colors to use for the conversion which is not possible.

Well, i guess i will have to continue with my awful 16 colors conversions :p

Posted: Sat Jan 19, 2013 7:05 pm
by bastien
I use paint shop pro for reduce color after the Xi magic dithering.
For Free software i think The Gimp can made that too.
maybe you can find some other solution here ( french link):
http://www.yaronet.com/posts.php?sl=&h=1&s=150367

Posted: Sat Jan 19, 2013 8:07 pm
by sega16
Stef wrote: sega16>Thanks :) I tried your directcolor tool but again can't get what i want : i used the i3 switch as i want to convert for genesis palette but resulting images do not fit in the RGB333 space but in RGB666 (i can have color as #D86448 for instance).
I also want to specify the number of maximum colors to use for the conversion which is not possible.
No my program is not RGB666 it is RGB333 colors but for RGB333 mode it outputs each pixel in sega genesis palette format which is BBBxGGGxRRRx x is always 0.The forumla for converting to 3bit is (x+18)/36
So 255 would end up as 7 which is the 3bit max value.

Posted: Sat Jan 19, 2013 8:55 pm
by Stef
sega16 wrote:
Stef wrote: sega16>Thanks :) I tried your directcolor tool but again can't get what i want : i used the i3 switch as i want to convert for genesis palette but resulting images do not fit in the RGB333 space but in RGB666 (i can have color as #D86448 for instance).
I also want to specify the number of maximum colors to use for the conversion which is not possible.
No my program is not RGB666 it is RGB333 colors but for RGB333 mode it outputs each pixel in sega genesis palette format which is BBBxGGGxRRRx x is always 0.The forumla for converting to 3bit is (x+18)/36
So 255 would end up as 7 which is the 3bit max value.
Strange... i obtained an image with colors outside that range, for instance color #D86448 which give :
B: 01011000
G: 01100100
R: 11010000

I forgot to mention that i tested that by using -i3 to do conversion then i used the -o switch to get back an "normal" image from the genesis directcolor image.

Posted: Sat Jan 19, 2013 9:10 pm
by Stef
bastien wrote:I use paint shop pro for reduce color after the Xi magic dithering.
For Free software i think The Gimp can made that too.
maybe you can find some other solution here ( french link):
http://www.yaronet.com/posts.php?sl=&h=1&s=150367
Thanks, i already tested the Xixxx tools and it appears they can't reduce colors and using specific space color at space time, you can do one operation or the other, but not both at same time which is what i intend to do : reduce image to 16 colors and keep result colors in RGB333 space.
That is really amazing since it does not sound as a very unusual operation but still i can't find any good solution for that :-/
The other tool "PNGQuant" is able to reduce colors but again, without color space restriction.

Posted: Sun Jan 20, 2013 1:11 am
by TmEE co.(TM)
I quantisize in PaintShopPro asd do color reduction in Irfanview or PSP, one works better for some things than other...

Posted: Sun Jan 20, 2013 11:32 am
by Stef
Yep well looks like we cannot quantize colors on image with a specified color space constraint, software probably exists but pretty difficult to find :p
I will just continue the old method, quantize then apply color space constraint ^^

Posted: Sun Jan 20, 2013 8:49 pm
by Chilly Willy
Or perhaps maybe sega16 can modify his direct color converter to do what you wish? Never hurts to ask. :D

Posted: Mon Jan 21, 2013 8:57 am
by Stef
Hehe i guess that is not that easy, good quantizer / color reduction algorithm exists but i think we cannot easily modify them to work on limited RGB space ;)

Posted: Fri Jan 25, 2013 12:07 am
by sega16
Chilly Willy wrote:Or perhaps maybe sega16 can modify his direct color converter to do what you wish? Never hurts to ask. :D
I have a better program that will be done soon. It is called retro graphics toolkit. It has a nice gui that lets you edit tiles. It also supports importing images.The way I handled color reduction is I downloaded an open source algorithm and then reduced the outputed colors to rgb333 colorspace and if the rgb888 to rgb333 conversion causes duplicate color it will try reducting with 17 colors and so on. It will stop at 256 colors to prevent infinate loop it also checks if the image has less or equal to 16 colors to begin with. I just have to fix a few glitches then it should be ready. I have no idea for a release date. However in the mean time my program is open source and I am sure that it is an easy fix.