Sign in to follow this  
PeterR

Cleaning up a DXT3 bitmap - can it be done?

Recommended Posts

Hi.If your starting point is a DXT3 bitmap i.e. one that has already been saved as a single layer image with an alpha channel embedded, is it possible to take it back to the non-alpha stage?As you'll know, all the default aircraft bitmaps in FS2002/FS9 are saved with alpha channels. This causes a greenish tint, usually, and a breakdown or deterioration of pixelation, which would get progressively worse if you kept saving revisions in DXT3 format as you added alpha layer after alpha layer! Clearly, the way to do it is not to save it with alpha until all work is complete. But, as I say, given a starting point of an image that already includes an alpha overlay, is there any way to remove it?Someone said ImageTool could do the trick but I've yet to work out how. But then, I'm a dork.Hopefully, someone with a brain can help, thanks.Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Open up the file (bmp) using image tool.Next click on "image - format - 24bit".Then save bmp file as a bmp file...That's it...

Share this post


Link to post
Share on other sites

HiGreatly apprecite your reply but can you be slightly more specific, please? There is no menu item IMAGE/FORMAT/24 BIT. There are various such as PROCESSING/MAKE 24 BIT and ANNOTATION/SAVE AS 24 BIT but then the image is 24 bit to start with and when I save in the latter manner the file is the same. So what to do?Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg

Share this post


Link to post
Share on other sites

Imagetool comes with fs2002 and its in a directory somewhere when you install the program. I just put a shortcut to it on the desktop as I use it a lot. Open the bitmap with imagetool, then go to the tabs (like above) and select format, check 24bit, then save. Now use dxtbmp to open it. I have my Dxtbmp configured to use paintshop pro as the editor. Once opened in dxtbmp i send it to PSpro and edit away. Im lazy so i have to redo the alpha channel each time because you will lose it once its reformatted to 24 bit, i dont mind, just an extra few minutes to redo the alpha too. Once you have it edited, the latest version of DXtbmp has an alpha generating tool so you can create an alpha template and edit it in Pspro (or whatever you choose) and then save it and refresh the alpha channel in dxtbmp. Once you do that you save it (minus mips) as whatever kind of texture you want in the drop down menus.Hornit

Share this post


Link to post
Share on other sites

Well, thanks all. However, the answer appears to be that you CANNOT remove an alpha channel once saved into a DXT3 bitmap.But first: 3green, our correspondence has educated me today as I referenced an entirely different program I have called Imagetool which, actually, is probably more sophisticated than the FS one; UTHSCSA ImageTool. Hence, my confusion as to your explanation.Secondly: Hornit, yes it is in FS2002 but I never knew that; I wonder how many others don't. It's buried in there, ain't it? The location is FS2002/GMAX/FLIGHTSIM/GAMEPACKS/FLIGHTSIM/IMAGETOOL.EXEThirdly, it doesn't help. I tried taking a DXT3 image back to clean non-alpha 24-bit with ImageTool but the alpha ghosting remains; as, frankly, I thought it would because, after all, it is a single layer image once it is saved as a bitmap. So, apart from doing all the usual graphics tricks to recolour, sharpen, lighten or whatever, it seems that one is stuck with the problem.In other words: for anyone repainting default aircraft (where no paint kit with original layered bitmaps is available) and you are working on existing bitmaps rather than creating totally new ones from scratch, you must paint over the residue of the first MS alpha save and then add in the alpha once more when your editing is finally complete, thus further deteriorating the image. Ah well. Mark "Dark Moment" BeaumontP.S. Bones ... what is your version of ImageTool?http://www.swiremariners.com/newlogo.jpg

Share this post


Link to post
Share on other sites

Hi DM,Forget what I said about versions - I was thinking of MakeMDL when I wrote that.. My ImageTool is the standard ACS Microsoft version - as it says in the Help.. About.. menu.But Hornit is correct when he says you can separate out the Alpha from the DXT3 image with DXTBmp - something that ImageTool cannot do.boneshttp://fsaviation.net

Share this post


Link to post
Share on other sites

Mark, Not sure what you are doing to lose image quality. When I do it here(as I stated above) all that happens is you basically lose whatever was in the alpha channel prior to the conversion. Its still there, just usually all white with an occasional anomlay or two depending on the texture prior to the conversion. What I tried to say, was you will have to redo the alpha channel totally after each tweak. I use the alpha template to redo it with the latest Dxtbmp. It works fine and I lose NO quality no matter how many times I do it, even on the same texture. The only huge pain in the butt, is every time I change the texture (after converting, saving etc) I have to come back and redo the alpha. So what I do now is just wait on the alpha until i hve the colors and placements right or in "final" form. I then reformat back to 24 bit and use the alpha template to create my alpha channel and save it all one last time. Im pretty sure there is a way to save the alpha channel to use later, but I havent found a way to do it that doesnt involve tons of open windows to do it, sometimes theres not enough memory to do it either!Hornit

Share this post


Link to post
Share on other sites

Hi Jim,Like you, I've done a few repaints so basically know my way around DXTBmp etc. It would be impossible to work without it, as you know, where you need Alpha channels for FS2004/FS2002. Comments to yours:<<>>No, not so, surely. Firstly: I lose no quality from the moment I start painting until I am finally ready to add the alpha. I save in 16, 24 or 32 bit up to that point and then DXT3 with alpha finally - and once only, to avoid multiple overlay and thus deterioration - for those textures needing transparency/reflection. The whole point of my thread was whether it is possible to REMOVE the effects of the alpha channel that MS add into their default bitmaps, if I am to use one of those - i.e. the DC-3 - as a starting point.I do not redo the alpha after each tweak - I simply "send it to Editor" when I first open the file in DXTBmp, save it as TRANSBK (by default it is TRANS, and yes, you will lose it every time if you don't do this) and then when I come to add it at the end, I simply reload TRANSBK as TRANS. Very straightforward, never have to redo the alpha. Unless, of course, I create one from scratch, which I usually do for my DC-3s as they all have different window sizes/number/positions/curtains etc. ... but I never have to do it more than once using this method.I think, to answer my own thread and based on input I've had, the only way to start with a clean palette is to paint the whole caboodle from scratch. But having said that, the MS default bitmaps are not too bad; it is just that, effectively, when you finally add your own alpha channel to their bitmap i.e. save your repaint as DXT3, then you ARE adding a second layer of alpha to the bitmap. Thus, more clouding of the image with those horrid greenish squares. Clear as mud?Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg

Share this post


Link to post
Share on other sites

HornitIf you want to edit a DXT3.bmp and save the Alpha channel, use image tool that came with FS2002 Pro and do it this way.1. Open up the DXT3.bmp using image tool.2. Click on "image - format - 32bit".3. Now when you go to save the texture, do a "save as" and call it some name with the extension ".tga".For example, save file as: B737-400l.tgaNow you can edit the this file "b737-400l.tga" and the alpha channel is kept intact.When you're finished editing, use image tool and convert the image back to DXT3 format.. You're Alpha should still be there..

Share this post


Link to post
Share on other sites

I guess I understand you Mark, but I just dont get that greenish tint thing unless i forget to reformat into 24 bit and work on the texture and then save it that way. Then I get the ugly green squares! I know I have done this when tired and doing a lot of painting. I will give that .tga extension a try, thanks! First though I have to try and stop the stutter on my machine. Its not bad, just seems fps are all over the place with this sim and its a bit annoying here.Hornit

Share this post


Link to post
Share on other sites

"I'm worried I might be getting a nasty attack of sledgehammeritis"HA! I hear ya! Its not bad on my system really, but I expected more. I mean Im running a p4 at 2.94ghz, 512mb ram and a GF4ti4200 128mb card. I would think thats enough but apparently it aint. Im thinking a newer generation card would do it here, but this one needs to last a bit longer.Hornit

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this