Do PNG images hurt vanilla compatability?

[hardcore_gamer]

I want to have a new inter screen in my wad. But if i use anything else that png format (like bitmat) it always looks messed up in game. And yes i am going to stick to PNG just couse i am lazy. I know vanilla Doom does not support PNG images. But does that mean that the wad could no longer be played with vanilla or ports that don't support PGA format images?

[myk]

For files to work on anything they need to be in Doom's graphics format, using 256 colors, and DOOM's palette. PNGs are not in that format, and they can be either 256 color graphics (using any one palette), or full color pictures.

[printz]

Damn. Just load that file having whatever format you wish, load it into a wad by using XWE. It's intelligent, seems to guess the game you're working for, so it knows how to translate the palette into Doom and not Heretic or others.

[hardcore_gamer]

myk said:

For files to work on anything they need to be in Doom's graphics format, using 256 colors, and DOOM's palette. PNGs are not in that format, and they can be either 256 color graphics (using any one palette), or full color pictures.

You seem to be missing the point. I know that Vanilla Doom can't read png images. But some ports like Zdoom can. Soooooooo i was wandering if a new tittle screen made with a PNG image would work with Zdoom and at the same time do so without hurting play in vanilla Doom.

[myk]

How about trying it and answering the question yourself?

[hardcore_gamer]

myk said:

How about trying it and answering the question yourself?

Well Doom 95 crashed. Why do all of my Bitmap images look like crap ingame?

[printz]

Odd, unless you use XWE. Dunno of other graphic workers, but both XWE and DMGRAPH (this time only for GIFs) can translate palettes.

If it's XWE's fault, I guess you should "teach" it to convert the palette to Doom's. Like loading a Doom wad, importing your graphics and cut-pasting it to your wad. Will it look right?

[hardcore_gamer]

printz said:

Odd, unless you use XWE. Dunno of other graphic workers, but both XWE and DMGRAPH (this time only for GIFs) can translate palettes.

If it's XWE's fault, I guess you should "teach" it to convert the palette to Doom's. Like loading a Doom wad, importing your graphics and cut-pasting it to your wad. Will it look right?

I don't use XWE, i use slumped.

[ReX]

hardcore_gamer said:

I don't use XWE, i use slumped.

Regardless of the utilities editor you use, the end result will depend on the original graphics palette. There are some colors that translate very well into the DooM graphics format (DGF), while others mess up really badly. There's more of a hit-or-miss when you're using png format graphics, as this format allows a far greater range of colors than DGF supports. Let me clarify one thing - each individual png image can only contain 256 colors; however, each image can support a different 256-color palette. This allows for many more than 256 colors in-game. However, it also means that when a utilities editor (such as XWE, DeepSea, or SlumpEd) has to translate all these colors into DGF, some (and, occasionally, many) colors get messed up.

[Maes]

There's a bit of confusion here...to sum up:

1. PNG doesn't hurt compatibility more than BMP or GIF or PCX do if the editor you're using converts them to DGF anyway, which it usually does UNLESS YOU SPECIFY OTHERWISE.
   
2. Leaving them in PNG format inside WADs is a special case: only a few ports will accept that, and all will perform a palette downgrade to Doom's One True Palette using a nearest color method, even GL/Direct3D rendered ports.
   
3. Most known tools (XWE, WinTex ...) are able to do AT LEAST a "nearest color approximation" to Doom's 256 color palette. I don't know if SLUMPED, of all tools, doesn't do that. If so, it sucks and you should stop using it.
   
4. I don't know what you mean by "looks like crap", but you may either mean a complete lack of palette conversion/error loading images (which will look like garbage and/or scrambled colors) and it that case you must try another editor.
   
5. Or it could just be a classic case of poor palette conversion, which is another big topic on its own, and there are a LOT of threads on this argument, refer to them for more info.
   
6. If you are going to load a lot of external images and custom graphics, I strongly suggest you learn to do your own palette conversion with some program like PSP. Try applying the Doom palette to every image you want to use in PSP, see if the results satisfy you. If not, try a different color reduction method and/or manipulate the image so that it renders more satisfactorily.
   

[TheDarkArchon]

Maes said:

• Leaving them in PNG format inside WADs is a special case: only a few ports will accept that, and all will perform a palette downgrade to Doom's One True Palette using a nearest color method, even GL/Direct3D rendered ports.
  

Wait, what?

[Graf Zahl]

The only port I know that did that was ZDoomGL because it simply used the software renderer's texture manager. To my knowledge all other GL ports that allow PNGs in WADs can handle their true palette.

[Maes]

Graf Zahl could be right, I didn't try other GL ports other than GZDoom, ZDoomGL and PrBoomGL. Both GZDoom and ZDoomGL do suffer from that limitation however, they were the reason mac53 started complaining about his "NEW and ENHANCED!" sprites: GZDoom just kept downgrading their palette no matter what. I don't know what PrBoomGL would do though...in any way, it's a murky argument, and as I said, except from Delphi Doom, no other port has had true, full truecolor texture management so far, and even GL ones are subject to many limitations.

[TheDarkArchon]

He was doing it wrong. GZDoom fully supports 24-bit PNGs as long as you are in the GL renderer.

[Graf Zahl]

Maes said:

Graf Zahl could be right, I didn't try other GL ports other than GZDoom, ZDoomGL and PrBoomGL. Both GZDoom and ZDoomGL do suffer from that limitation however,

GZDoom does *NOT* have this limitation. I wonder why you think that.

they were the reason mac53 started complaining about his "NEW and ENHANCED!" sprites: GZDoom just kept downgrading their palette no matter what.

That is simply not true. I never checked mac's sprites but this was most certainly a user error, nothing else.

I don't know what PrBoomGL would do though...in any way, it's a murky argument, and as I said, except from Delphi Doom, no other port has had true, full truecolor texture management so far, and even GL ones are subject to many limitations.

What do you consider 'full true color texture management'? It must be something different than what I understand. GZDoom can load true color PNGs (24 and 32 bit), JPGs, TGAs and PCXs. And they all will be displayed with their full color information. And I am sure that the other GL ports can do the same thing.

[TheDarkArchon]

Doomsday can handle true colour PNGs, though I'm not sure about other formats.

[ReX]

Keep in mind that hardcore_gamer wants to have compatibility with both doom/2.exe and ZDooM. In other words, he wants to be able to use png-format graphics that won't bork up when using either doom/2.exe or ZDooM. Nobody can assure this (unless by some happenstance the png graphics have colors that convert well to DooM Format Graphics).

[Maes]

Here's the original "NEW and ENHANCED!" sprites thread by mac53, although the original download links to DM2Sprites.wad and DM2sptspng don't work (I can send a copy to anyone PMing me though).

http://www.doomworld.com/vb/xwe/39427-doom-2-sprites-project-inquiry/

In that way, you can judge for yourselves if mac53 did something wrong or not. However, the file DM2Sprites.wad consists simply of a bunch of "enhanced" sprites reduced to Doom's palette upon loading, so no wonders/surprises here. The colors and edges are altered compared to the original sprites, and whether they look better than the originals is debatable.

The other file, DM2sptspng.wad contains the "original truecolor PNGs" and the two most obvious problems are:

• They are not aligned to the screen
  
• Have no transparency (so they appear like cyan boxes surrounding something).
  
• They are downgraded to 256 colors anyway, for some reason, or at least they convey this impression.
  

Due to the bad quality of the "enhanced" sprites and the OpenGL filtering, it's really hard to understand if they are rendered as truecolor or are color-reduced first.

In any case, if hardcore_gamer's problem is JUST a palette problem, then the issue has been addressed countless times in other threads, and has little to do with the PNG format itself.

I would sum it up as in: "Reducing any given, random image's palette to Doom's One True Palette with satisfactory results is more of an art than a methodology".

Surely not what one wishes to hear when he has e.g. 100s of 1000s of images to process but that's the way it is, sorry.