How to reduce colors in iff/ilbm images?

[MickGyver]

Hi! I'm trying to figure out a good workflow for using Cosmigo Pro Motion to create graphics for an Amiga game. Pro Motion can save images as iff but the problem is that those images will be 256 colors.

Is there a tool that can batch reduce the colors of iff images? I tried XNView and NConvert that comes with it. It almost works, colors can be reduced but the order of colors in the palette is altered (the original images made in Pro Motion only uses the first 32 colors).

[Amiga1992]

I know this isn't the answer you want, but how married are you to Cosmigo Pro? because grafx2 can work with smaller palettes.

At the very least I am sure you can use it to load your work and save properly, but it won't batch.

[idrougge]

PPaint.

[Shatterhand]

I second Grafx2 . This app has been a Godsend for me to work/draw amiga graphics.

[nobody]

Grafx2 for the job you want to do. Promotion is a superior package for making 256 color pixel art. It has a truck of features you won't need for a (usually) simple Amiga job.

[Amiga1992]

grafx2 is really great, I refused to use anything but DPaint IV for years, but grafx2 changed all that.

There are some missing features I would still love to have (like color cycling), otherwise it's amazing.

[MickGyver]

Thanks for your suggestions, I appreciate it! I tried grafx2, it can reduce the palette colour count but for some reason it removes the colours that are not used in the images, is there a fix for this?

To clarify, the graphics are already made for the PC version of the game but need to be reworked for 16 or 32 colours. Pro Motion have good tools to remap colours etc so it would be the best solution to manually reduce the colours and my pixel artist is also used to that program. I'm not familiar with grafx2 and I know that my pixel artist is not too keen on using another tool.

This will leave the final conversion to me, and the only thing i would need to be able to do is just reduce the palette with not changing the colours in the used indices. I know I will have to do this several times so i'm not too keen on doing it manually either.

I tried Personal Paint and it seemed to be able to reduce the colour count without any problems. It can also be automated with arexx, the only problem now is that I don't have any documentation for the arexx commands for ppaint, is such a reference available?

[MickGyver]

I managed to figure out the ARexx commands needed from the examples supplied with PPaint. I made a script that converts all png images in a folder to iff/ilbm reducing colours if you specify the target colour count in the filename (like image[32].png). This method seems to work ok. If more colours than target colour count are used in the image, the colours will be remapped, otherwise the colour count is just reduced (not changing the palette read from the png image). I'm including the script here if somebody else needs it.

/* Personal Paint Amiga Rexx script */

/* $VER: PngToIff.pprx 1.0 */

/* 
This script will convert all png images to iff/ilbm in the folder where the script is run.
The colours will be reduced if target colour count specified in the filename
inside brackets, for example: image[32].png
More than 2MB RAM will be needed for larger images
*/

IF ARG(1, EXISTS) THEN
	PARSE ARG PPPORT
ELSE
	PPPORT = 'PPAINT'

IF ~SHOW('P', PPPORT) THEN DO
	IF EXISTS('WB31:Apps/PPaint/PPaint') THEN DO
		ADDRESS COMMAND 'Run >NIL: WB31:Apps/PPaint/PPaint'
		DO 30 WHILE ~SHOW('P',PPPORT)
			 ADDRESS COMMAND 'Wait >NIL: 1 SEC'
		END
	END
	ELSE DO
		SAY "Personal Paint could not be loaded."
		EXIT 10
	END
END

IF ~SHOW('P', PPPORT) THEN DO
	SAY 'Personal Paint Rexx port could not be opened'
	EXIT 10
END

ADDRESS VALUE PPPORT
OPTIONS RESULTS
OPTIONS FAILAT 10000

Version 'REXX'
IF RESULT < 7 THEN DO
	RequestNotify 'PROMPT "'txt_err_oldclient'"'
	EXIT 10
END

LockGUI
tmpfname = '_filelist.txt'
ADDRESS COMMAND 'List >'tmpfname' NOHEAD PAT=(#?.png) LFORMAT="*"%s%s*"" FILES'
IF OPEN('listfile', tmpfname, 'R') THEN DO
	DO FOREVER
		curfname = READLN('listfile')
		IF EOF('listfile') THEN BREAK
		LoadImage curfname 'FORCE QUIET'
		IF RC = 0 THEN DO
			LoadBrush curfname 'FORCE QUIET'
			GetBrushAttributes 'WIDTH'
			xmax = RESULT - 1
			GetBrushAttributes 'HEIGHT'
			ymax = RESULT - 1
			GetBrushAttributes 'HANDLEX'
			hanx = RESULT
			GetBrushAttributes 'HANDLEY'
			hany = RESULT
			IF POS("[32]", curfname) > 0 THEN Set '"COLORS=32"' 'FORCE'
			ELSE IF POS("[16]", curfname) > 0 THEN Set '"COLORS=16"' 'FORCE'
			ELSE IF POS("[8]", curfname) > 0 THEN Set '"COLORS=8"' 'FORCE'
			ELSE IF POS("[4]", curfname) > 0 THEN Set '"COLORS=4"' 'FORCE'
			ELSE IF POS("[2]", curfname) > 0 THEN Set '"COLORS=2"' 'FORCE'
			ELSE Set '"COLORS=256"' 'FORCE'
			len = LENGTH(curfname)
			newfname = SUBSTR(curfname, 2, len-6) || ".iff"
			DefineBrush 0 0 xmax ymax
			IF RC = 0 THEN DO
				SetBrushAttributes 'HANDLEX' hanx 'HANDLEY' hany
				SaveBrush newfname 'FORMAT ILBM' 'FORCE'
			END
		END
	END
	CALL CLOSE('listfile')
END
ADDRESS COMMAND 'Delete >NIL: 'tmpfname
UnlockGUI
Quit 'FORCE QUIET'

[WayneK]

Originally Posted by witchmaster

Thanks for your suggestions, I appreciate it! I tried grafx2, it can reduce the palette colour count but for some reason it removes the colours that are not used in the images, is there a fix for this?

Yes, the fix is just include every colour in the image... eg: a 16col image, draw a 16-wide stripe of 1 pixel of each colour. Then when you convert from IFF->RAW just exclude the extra pixels (or cut them off in a hexeditor, whatever you prefer).

[Amiga1992]

Originally Posted by witchmaster

Thanks for your suggestions, I appreciate it! I tried grafx2, it can reduce the palette colour count but for some reason it removes the colours that are not used in the images, is there a fix for this?

I think if you move all colors to your first 16/32/whatever, and then zero out everything else, it will save as that amount of colors. If you use "reduce", it will zap the unused, yes. (it would be a good suggestion to change this behaviour, I'll make it)

Another tip: load an image with at least one pixel of every color in it, order the palette the way you want, hit zap/reduce, to make sure you just have those.
Then you can SAVE The palette. Use format PAL to save, this will only save the palette. Load the palette onto any image you want and it will use the colors and order you saved.

[MickGyver]

Originally Posted by WayneK

Yes, the fix is just include every colour in the image... eg: a 16col image, draw a 16-wide stripe of 1 pixel of each colour. Then when you convert from IFF->RAW just exclude the extra pixels (or cut them off in a hexeditor, whatever you prefer).

Originally Posted by Akira

I think if you move all colors to your first 16/32/whatever, and then zero out everything else, it will save as that amount of colors. If you use "reduce", it will zap the unused, yes. (it would be a good suggestion to change this behaviour, I'll make it)

Another tip: load an image with at least one pixel of every color in it, order the palette the way you want, hit zap/reduce, to make sure you just have those.
Then you can SAVE The palette. Use format PAL to save, this will only save the palette. Load the palette onto any image you want and it will use the colors and order you saved.

Cheers! Zeroing out the unused colours and saving seems to work fine.