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LuisFelizTirado

Getting Images from Terraserver

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In the TerraBuilder forum Rhumbaflappy brought up the fact that using Terraserver you can get it to project the pictures in geographic coordinates. The intrigued me, so I spent a little time there and found that it is indeed possible to get it to project the images in geographic projection, and with a little care, get them to the correct size in degrees per pixel.The thing that I am most interested in now is using the programming tools that Terraserver has provided to automate the process to get images as large as 8192 x 8192 pixels to cover an entire LOD 5 quadrant. Unfortunately I am not a programmer. I am an engineer and I understand the mathematics, and could outline a program that I think could be extremely useful, but I don't think I could program it. I am looking for a programmer to collaborate on developing a program similar to USAPhotomaps to get images from Terraserver, but having the result being in geographic projection at the correct resolution for FS. Anyone interested?Here are some of my observations:Photo Resolution. The first idea that we need to change is that the end result photographs that we need are not 4.8 m/pixel but the result needs to be in fractional degrees per pixel. In geographic projection we need to concern ourselves with degrees per pixel. Each LOD13 cell is 0.0146484375

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Hi Frank,interesting idea. I'm not currently interested in photoreal projects but I'm having a bit of a hard time "buying" the 8192x8192 pixel requirement for an entire LOD5 section. Without trying to follow your math, knowing that the approximate span of a LOD5 cell is about 313km, I'd figure that a 4.8-m photoreal image would have to be more like 65,200 x 65,200 pixels in size! ... then again, maybe I'm out to lunch here???Cheers, Holger

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Hi Frank.Holger's right. It would be 65536 x 65536 pixels if pre-scaled to LOD 5. I also am not sure a prescaling is needed. Having larger than the 4.8 pixels/meter would loose image quality, but having finer resolution would be fine, as resample will scale it down correctly.The limitation of 2000 x 2000 pixels forces us to scale an image at no more than 0.11*long x 0.85*lat to maintain resolution.... and they must overlap enough to compensate for the USGS logo, if it is present. Then they can be stitched together.Generally, photoreal is best used for smaller areas, like an airport or city, and VTP and LWM lines and polys for outlying areas. There have been some photoreal projects done commercially for larger areas, but I'm not a big fan of those sceneries ( no autogen, no seasons, don't blend into the default scenery ).The huge size of the image for an LOD 5 would be a problem. It would be better to use the older resample with it's TMF tools, and merge smaller TMF's before creating the final BGL... then small areas could be resampled independantly. Alternately, the placement BGL for photoreal is simply a landclass BGL, using #252 ( all seasons ) or #253 as the fill number.Dick

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Sorry, it was late went I wrote that last night. I meant an LOD8, not LOD5, would be 8192x8192.The program I would like to have created is not limited to 2000x2000, and the images would not have the USGS logo. It would not be that hard to add a utility to create the inf file ready to run through resample. The image size selected could be anywhere between 256x256 to 8192x8192. For input to select the area I would use the latitude and longitude of the area where coverage is desired. It could be used for an area up to 8192x8192.Resample would not be doing any resizing at all with these photos, as they would already be at the exact resolution and projection required.Frank

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Hello Frank,Nice to see you around after a long absence. I really like your idea. It would certainly make things simpler.And the image would not be limited to conversion to custom textures, but could also be used as a guide for creation of VTP and L/WM. This would provide a better option for those programs that use backgound bitmaps for terrain creation. Best regards.Luis

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Thanks Luis.Things have been rather hectic for a while (I got involved in doing a couple of plays during the summer). I don't know how much time I can spend in checking the forums, but I think that this program I want to develop would be useful for many things other than just photoreal. Like you said, they could be used for backgrounds and guides. I can program a bit in Visual Basic, but I have never used C# or the .net stuff that they talk about. (I first learned to program in Fortran using punch cards.) I think this program is a bit beyond my capabilities.Do you know a programmer who might be capable and willing to help? I want the program to be free for the flight sim community.Frank

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Perhaps Doug Cox would be willing to add these capabilities to his program. He already has the most important parts and would only need to make small modifications to USAPhotoMaps.Have you tried putting the suggestion to him?Best regards.Luis

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