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Instrument Graphics

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Instrument Graphics

Postby pauljs75 » Sun Jan 28, 2007 4:48 am

Figured that this could be a thread for posting instrument graphics.

I'll start with my 'nicer' version of the radar screen stuff from the harrier.

Image

Also anyone know the merits of .rgb over .png or .jpg, or even .tga (which seems common for games)? It seems to be an uncommon graphics format.
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Postby RatOmeter » Sat Feb 03, 2007 6:35 pm

Also anyone know the merits of .rgb over .png or .jpg, or even .tga (which seems common for games)? It seems to be an uncommon graphics format.


For the purposes of modeling for FG, .rgb .png and .tga can probably be considered interchangable as they all support color depths suitable for FG and support no compression and lossless compression. JPG is the only one out of the bunch that supports lossy compression and, IMO, should be used carefully when saving to avoid gaining compression artifacts.

If my understanding is correct, FG uses only .rgb files for textures so you'll need to end up in that format. Despite what I've read at the FG wiki, the rgb/sgi format is not supported by a lot of common commercial "paint" programs (such as Adobe Photoshop), but the GPL'd GIMP/GIMPshop does.

In summary, I don't see any real value in working with JPG images but the other formats mentioned are fine. In fact, if you start from a JPG on an image with relatively few colors (no shading, using a few discrete colors as on a panel gauge or similar), lossy compression artifacts may cause the image file to be unnecessarily large when converted to .rgb with RLE compression. Run Length Encoding compression is ideal for images with just a few, discrete colors and the speckles that can result from lossy compression can trip up the RLE algorithms when converting between formats.

Imagemagick is/has a great image file format conversion utility which does a really nice job moving between these formats.
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Postby ajm » Sat Feb 03, 2007 7:43 pm

Actually, FG does support other image types for textures (though not many models use them), but I can't see much reason not to use rgb / sgi since it's so well supported.

I'm not a Photoshop user, but a very cursory google showed up several plugins which allow reading and writing SGI's .rgb files. Like this one, for example http://www.telegraphics.com.au/sw/#sgiformat

But like you say, Gimp, Imagemagick etc handle it perfectly too.

Cheers,

AJ
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Postby RatOmeter » Sat Feb 03, 2007 10:04 pm

I'm glad to hear that rgb/sgi is not the only image file format supported, but like you said, it seems to be the best supported (I haven't yet found a model that used anything else).

I had a sinking feeling that I should have checked for PS plugins before I spouted off about its support for the sgi format ;) Thanks for clarifying.

I guess I should offer a caution on using Imagemagick for file conversions; I was trying to test some of the things I said earlier and was startled to find that Imagemagick's converter changed a 40kb rgb file to a 145 kb jpg in converting it. I think it must have assumed I wanted to convert it at the same (lossless) quality level. Lesson learned: always check the file size and image quality after a conversion ;)
Last edited by RatOmeter on Mon Feb 05, 2007 3:00 pm, edited 1 time in total.
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Postby ajm » Mon Feb 05, 2007 12:49 pm

Indeed... this also seems like a good place to remind people that when saving RGB files in gimp, one should always use the "Agressive RLE" compression option and ignore any "not supported by SGI" warnings.
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Postby tcbetka » Wed Mar 07, 2007 1:25 pm

After reading this thread a few weeks ago I went and easily found a plug-in for Photoshop. The hardest thing was finding out where to put it but once I did, PS now handles the .rgb files with ease and the results are excellent.

This thread (as well as the mIRC chat group) was extremely helpful.

TB
MD, CFII, A&P
(Aero Eng Student)
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