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LuisFelizTirado

Colored Satellite Picture Questions

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Hello everyone, I just started trying to use TerraBuilder Lite, but I'm obviously dazed and confused...What SIZE dimensions do you need for the satellite picture? How do I know if it's going to be too big or small? The instructions say I will need a "Windows BITMAP (BMP) picture of the scenery you wish to design. The COLOR DEPTH should be TRUE COLOR, RGB Mode, 24-Bit color depth." Forgive my dumb question, but will any size pictures work???????Also, how do you get COLOR satellite pictures like the one used in the Niagra Falls example? It seems to me just from reading, that the hardest part of using the program is getting the proper colored bitmaps you need! Does there exist a REALISTIC tutorial that walks you through capturing a color satellite image and then using the program? Thank you kindly for your responses, as I am really trying to learn this new skill...Regards,SteveSYSTEM SPECS:Dell 8200 P4 2.6 Ghz, 768 RDRAM 800, 80/120 GB ATA133 HDD, GeForce4 Ti4600 w/44.03 Omega Drivers, DirectX 9.0b, WinXP Home, SoundBlaster Audigy 2 with 6.1 speakers, CH Products Flight Sim Yoke USB, CH Products USB Rudder Pedals

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Hi Steve:I have never used Terrabuilder but have made photoreal textures for FS2002/2004 based on satellite imagery. I can provide pointers about the pre-processing/coloring of the bitmaps but I'd like to find out first whether you're actually interested in using satellite images? The Niagara Falls example is based on aerial photography (more precisely, "orthophotograpy", as it is optically and geometrically corrected to fit a geographic projection). Most photoreal designers use these kinds of images as they have a higher resolution (1 to 4 meters, compared to the 15-m satellite images I've been using). Do you have a specific image already? If so, what are its specs? Cheers, Holger

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Hello Steve,Generally, satellite images do NOT give good results when converted to ground textures, because of their limited detail and low resolution.As Holger says, you need aerial images. Get 1 meter per pixel images for Michigan at mapquest.com or the Microsoft server for U.S. Geological Survey images at http://terraserver-usa.com/ .The Terraserver images can be downloaded automatically and assembled using some very handy utilities by Doug Cox, available at http://jdmcox.com/ .Often, only black and white images are available, so you must learn to color them. This is really not as difficult as it may seem. The U.S.G.S. images do, in fact, have color information, and can be colored using a good image editing program.If you can get 15 meter per pixel satellite images, you may get very acceptable results like Holger, but normally we all use images that come close to the default Flight Simulator resolution of 4.76 meters per pixel.How large can your image be? My largest project has been the entire Paris metropolitan area, 30 km. x 20 km., 600 square kilometers. The limit is really your available memory.What is the smallest image that can be used? Normally, a ground texture is about 1.2 kilometers to a side and the Microsoft Resample program needs to fill the ground tile completely with your image. Your image may not fill a ground tile completely if it overlaps the boundaries of the ground tile, so you should count on using an image that is about 1 kilometer larger on each side than what you want to convert to ground textures. Any part of your image that does not fill a ground tile will NOT be converted to ground textures.TerraBuilder is very easy to use, only please avoid the common pitfalls: - read the simple instructions provided by Misho. If you follow them carefully, you will have no problems; - use the Phototerrain Wizard, NOT the PhotoWizard.Any problems, do not hesitate to ask here.Best regards.Luis

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Luis,You said that U.S.G.S. images do, in fact, have color information. I thought that they were just 256 greyscale. How do you get the color information? What color information is available?Frank

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>Luis,>>You said that U.S.G.S. images do, in fact, have color>information. I thought that they were just 256 greyscale. >How do you get the color information? What color information>is available?>>FrankHi Frank,You can get them here:http://edcsns17.cr.usgs.gov/EarthExplorer/and here is an example of Golden Gate Bridge from that site:http://edcsns17.cr.usgs.gov/cgi-bin/browse....NWS.829398.jpgYou can log in as a guest and browse. Preview resolutions are good enaough for 4.8 m/pix conversion and SOME of them come in color. You can tell which ones are in color in the Results table, in the Product Group column. For black/white it says "3.75-MIN B/W" and for Color it says "3.75-MIN CIR" Some of the color may be false (greens are reds) but a simple color replacement in Photoshop will do the trick...Hope this helps.

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All of the available images in my area are B&W.From Luis' statement, I thought he was saying that even the B&W images had some color information.Frank

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Hello Frank,Yes, you are right, the USGS images are 256 shades of grey and I meant that these shades are color information.I use Photoshop to color the images - there are 3 means to do this: - using the Variations option, one can roughly add color. This is not very precise, and probably should only serve as a first phase, if at all; - I usually just use Color Balance and add and subtract different colors until I get an acceptable result. Then, I save the color table for use in other images. However, color assignments (greyscale shades) seem to be assigned differently in different parts of the U.S. For example, a color table for Gulfport, Mississippi will work in Arizona (desert!) quite well, but not in Florida; - it is also possible to directly edit the color table, and this is a good final step to finely adjust the result.Here is an example of the work:the original USGS image of Gulfporthttp://forums.avsim.net/user_files/44893.jpgAnd here are the resulting ground textureshttp://forums.avsim.net/user_files/44894.jpgOf course, there are other methods of coloring images. Misho has a very good method that he has explained here (and his night textures are stunning and the best that I have ever seen), as has Bob Bernstein.On another note to Steve, another pitfall with TerraBuilder: it does not presently support the creation of altitude mesh. Do not provide a source for this and just skip that step in the wizard.Also, I am usually up at dawn here on the farm and check the fora first thing before having my coffee, so I am not always completely alert. My largest project of Paris is 30 000 pixels by 20 000 pixels, at 5 meters per pixel. That is 150 km. by 100 km., 15 000 square km. And others have made much larger projects, so the limitation so far is definitely your available memory.Best regards.Luis

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Howdy,just to add to the coloring info:1. search for 'greyscale' or 'grayscale' in the Scenery Design forum, as Bob has summarized his approach in a couple of posts.2. Ken Nelson has written a nice tutorial (based on Bob's and Richard's approaches, respectively) for colorizing: http://www.scenery.org/tutorials.htmCheers, Holger

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Hi everyone, thank you very much for all this information, it is very helpful and I appreciate your time. I guess what I'm really after is using the colored aerial images such as the ones I've pulled down from http://www.globexplorer.com I don't know enough about how to color satellite images. I can get these from http://terraserver-usa.com/ or by using the very cool program called "USAPhotoMaps" created by Doug Cox.If there are regions that only have black and white satellite pictures, I guess I will have to learn how to color those. Is there a tutorial anywhere that can further explain this to me? The Gulfport image below created by LuisFelizTirado is outstanding! That's what I want to be able to do! I'll tell you, if someone ever wrote a program that could "autocolor" satellite/aerial terrain images, I'd be the first in line to buy it! I still don't understand how you know the "meter per pixel" setting. How does one get this?I guess my first step in learning this, is understanding how to set-up the picture correctly. Can someone just walk me through the very first steps of preparing to capture a colored aerial image, and then the actual capture of the image. Do you have to make size/resolution/scaling, etc. adjustments??? Thanks for your help, the picture provided is what I am trying to work towards seeing...

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Hello Steve,There is a lot here, let's see - first, satellite images are not the same as aerial images.Here is a satellite image of Venice:http://forums.avsim.net/user_files/45613.jpgAs you can see, there is not much detail and it is NOT adequate as a source for ground textures.Here is an aerial image of Paris, converted to ground textures:http://forums.avsim.net/user_files/45614.jpgYou can easily distinguish streets, buildings, and other detail. Aerial images are what we use, and what you will find on the Microsoft Terraserver site. Aerial images are taken from airplanes flying around 20 000 feet, I think.As I indicated, coloring these images is not difficult and there is no need for an "autocolor" program. Or, rather, this already exists, and it is called Photoshop, or any good image editing program. The Photoshop help file even indicates exactly how to go about coloring "black and white" images. Just follow their easy instructions.I have not been to Globexplorer in a year and a half - that is where I got the Paris picture, but they retaliated for my slewing around the picture for a few months by placing their name over all their pictures and preventing their being used.http://forums.avsim.net/user_files/45615.jpgIdiots! From your picture, it would seem that they are no longer doing this.You do not have to worry about the resolution of the image, that is, how many meters per pixel. As long as it has good detail, then it can be used to make ground textures. However, if you want to know the resolution, then just look at the zoom slider in Globexplorer where this is indicated. In USAPhotoMaps, just look at the top of the window. If you get an image from some other source that does not indicate the resolution, the just zoom in on a runway or a footbal field, count the pixels and do the simple math.You DO need to know the geographic coordinates of the picture, but even if you don't have them, then Terrabuilder lets you determine them from certain features, for example, a runway.Just give Terrabuilder a try - it is not complicated to make ground textures, as you will see.Here are a another picture of Gulfport. I am not a graphics expert or an advanced user of Photoshop and yet it was easy to get this kind of color.http://forums.avsim.net/user_files/45616.jpgBest regards.Luis

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Unlike the normal picture attachments, Luis, your pictures show up in my IE6 browser as a little red x in a square. Left - Clicking on ithas no effect....right clicking gives only "Show Picture" with everything other option grayed out. ...and "show picture" does not seem to produce anything.....anyone know a remedy? I saw nothing in Internet tools.........

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>Unlike the normal picture attachments, Luis, your pictures>show up in my IE6 browser as a little red x in a square. Left>- Clicking on it>has no effect....right clicking gives only "Show Picture" with>everything other option grayed out. ...and "show picture" does>not seem to produce anything.....anyone know a remedy? I saw>nothing in Internet tools.........That is why I host my own images as if you host them here, AVSIM tosses them out after a short time, as a result we have lost all kinds of great bits O knowledge. :(

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Hello John,These were normal AvSim forum picture attachments, but, as Paul says, they are eliminated from the forum server, after 2 weeks time if I am not mistaken. But, they were just illustrations, not really essential to the explanations given. However, if you would like to see them, I shall be happy to put them up again.Best regards.Luis

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