batch file conversion to 16 colors (SOLVED)

[EnterTheStory (aka tolworthy)]

AGS uses 16 color bitmaps for walkbehind areas, floors, hotspots, etc, but I have a large number of such files from a previous game, all in high color. Any suggestions for how to batch process them?

I normally use Irfanview for batch processing, but if colors are close together it will dither them (even though there are only 16 colors in the entire image). Many other programs CLAIM to batch convert, but I've tried almost a dozen and they all have problems on this particular task. The only one I've found that really understands palettes is Alchemy for DOS, but it costs a hundred dollars and upwards.

Any ideas?

[Ashen]

Not really an AGS technical question, so I'll shift it to talk and chat.

Sorry I can't really help, except to suggest you try the All the paint programs you'll ever need.

[RickJ]

Gale may be helpful in this.  The process is not what you would typically "batch".  but you could import each of you bitmaps into separate frames of the same Gale file.  Convert the color depth of the file and all the frames are so converted.  Then just export the frames to individual PNG files. 

If it were me I would probably have one Gale file for each room that contained all the masks for that room.  I would probably also import an image of the room itself as a hidden layer of at least on of the frames.

[edit]
The other thing I would do is try importing the hi-color images you have into AGS as a mask to see what happens.  It may work?

[EnterTheStory (aka tolworthy)]

Gale may be helpful in this.  ... you could import each of you bitmaps into separate frames of the same Gale file.  Convert the color depth of the file and all the frames are so converted.  Then just export the frames to individual PNG files.

Would that work for different sized frames? 

If it were me I would probably have one Gale file for each room that contained all the masks for that room.  I would probably also import an image of the room itself as a hidden layer of at least on of the frames.

That sounds like a good idea in future. Right now I have a file structure designed for the previous game engine, and probably won't change it unless there is some major benefit. But future games will definitely be structured in a different way.

The other thing I would do is try importing the hi-color images you have into AGS as a mask to see what happens.  It may work?

Sadly not. That would be a very helpful feature. And so would the ability to accept images that are bigger than the background, and just ignore extra pixels. That way I could use a certain animation program that is very powerful, can do what I want, BUT outputs identical sized images.

[Edited to delete stuff that is no longer true]

After many hours of downloading, disappointment and experimenting, I think I've solved the problem. I've found a program that's basically a clone of Irfanview, but without the dithering.  I would give its name, but I'm only using a demo version, and the full license is very expensive for something I'll only ever use once. If I sell the game one day they may find this post and demand a huge business licence from me! If they ever offer a low cost license for indie game developers who work in their bedroom then I'll be happy to pay it and name the product and sing its praises. Until then, if anyone wants its name, just PM me.

[SSH]

Did you try unchecking the Irfanview box that says "Use Floyd-Steinberg dithering" in the batch advanced options?

[zabnat]

Did you try unchecking the Irfanview box that says "Use Floyd-Steinberg dithering" in the batch advanced options?

Probably not...

Since at least in Photoshop (and probably in any other decent graphics editing program) color reduction works fine if your picture really has only 16 colors, just set colors to 16, select no dithering and no forced colors and you should have an unaltered picture with 16 color palette.

[MrColossal]

You can also then create an action in photoshop that makes an image 16 colours and then from that create a droplet which is an EXE file that you can drop images on and it runs all the steps you recorded before... At least that's what I'm told, I've never tried it!

That is if you have photoshop

[EnterTheStory (aka tolworthy)]

Did you try unchecking the Irfanview box that says "Use Floyd-Steinberg dithering" in the batch advanced options?

I was using an older version of Irfanview that didn't give that option. Nice to see it's now offered - thanks for pointing it out.