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Guest andy58

Is Landsat-7 good enough?

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Thanks Holger Sandmanns tips I've made a test scenery using free available Landsat-7(BTW check Holger's Freeware Forum here http://forums.simflight.com/viewforum.php?f=231 )My concern is: is it worthy continuing as Landsat-7 data is generally 30m/pixel for color and 15m/pixel for B&W photos ...OK, here is the puzzle - who will be the first to tell where these shots were taken?:islandxxxbefore1cl.jpgislandxxxafter4db.jpg and the neighbour:islandyyybefore1tu.jpgislandyyyafter7uk.jpgWell, the Landsat-7 data is not what you should expect when utilize US USGS - it is 30m/pixel for color and 15m/pixel for black & white image but ... I like it and how do you? PS. I posted originally that info at http://forums.simflight.com/viewtopic.php?t=49601Cheers, Rysiek

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That first one looks kinda sorta like the island of Krakatoa...

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I probably wouldn't use the Landsat data as photo-real scenery, but instead I would limit thier use to making coastlines and landclass data (due to the resolution).- Martin

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Hi Rysiek,nice shots! It's a caldera in the first picture but which one I don't know ;-)I made those Landsat-based textures for the Everest area as an experiment more than anything else. Interestingly, I have received lots of positive feedback on it and quite a few requests for covering other areas of the Himalayas. I guess it works for that region because it's mostly rock and ice and the default land class and textures don't do a good job in portraying the variety of the barren surfaces. Moreover, I didn't have to worry about autogen and night lights.Keep in mind though that I "spliced" the 15-m panchromatic band into the spectral 30-m bands, which does help with the resolution. Also, I upsampled the image to 5-m resolution in Photoshop before sending it to resample.exe, which provides better control over interpolation. To do the splicing one can either do a RGB-to-HLS-to-RBG transformation, using the 15-m band as the "lightness" component for the HLS-to-RGB process, or directly blend the 15-m image in Photoshop using the "luminosity" feature.Cheers, Holger

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Thanks Holger again, and now for that procedure:"To do the splicing one can either do a RGB-to-HLS-to-RBG transformation, using the 15-m band as the "lightness" component for the HLS-to-RGB process, or directly blend the 15-m image in Photoshop using the "luminosity" feature."I will try it today. What I have done before was blending 15m B&W using opacity slider set to 50% to 30m color background ...More and more I look at that stuff then more I like to fly over it against any landclass coverage, even if it is blurry. Landclass is so artificial ...I hope that some additional experimenting with colors and sharpening will give enough good results to try cover some most interesting areas outside US and there are quite a few...Well, OK, the solution for the puzzle above is:http://www.santorini.net/geography.html :)

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Orca Island? maybe?BTW I am starting to work on the mount Waddington area in B.C using many of Holger's tips as well. Cheers Dan Martin

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I've been getting good results with NLT Landsat 7 Visible Color imagery with excellent alignment with SRTM 90 mesh. I uploaded an image the other day but something went wrong, probably me. There's screenshots on VirtualVFR if you want to check out how they look, particularly Reunion Island in the Indian Ocean.http://virtualvfr.com/Andy

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Thanks Andy, nice La Reunion and I just download your guides.My concern is still how to tune enough good the Landsat data, with right color and sharpness ..

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I normally resize the source image by 300% but sometimes only 200% depending on the effect it creates in the scenery in relation to sharpness. It's never going to be that great because by the time it comes out of Resample as scenery at 4.8m/pixel it's been resized 600%, 30m down to 5m. Even so, I find it suitable for criusing altitudes down to about 3000ft. and I get what it actually looks like out the window. It's quick and easy to make, 20-30 minutes from downloading in Worldwind to flying in Fsim and I can seamlessly join adjacent areas(the limitation is the source image accepted by Resample.exe, about 10000pixels high.I think I vary the gamma to adjust the colour but rarely need to with the NLT dataset.Andy

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I've come up with another little refinement. I mentioned I usually resize my 30m/pixel source mosaic by 300%(10m/pixel)using bicubic resample method prior to processing to avoid the coarse result you get if you let Resample.exe take it directly down to 5m/pixel. The 10m/pixel image has about 1/2 million colours so I tried reducing the colours to 32k colours and it had the effect of sharpening the image slightly, enough to make a difference for the better in the final scenery.Andy

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Hi again guys,as I proceed with some interesting areas to be covered with Landsat-7 textures, I would like to present you with a taste of Africa:Mount Kilimanjaro in an early morning light:kilim010wq.jpg...and some surroundings:kilim024jr.jpgDecompressed size of 160 x 120 km2 area may eat up (rough calculation) 50 - 80 MB download size and of 400MB HDD space. So, the question is still the same: will some of you be interested in installing such cover, if will be uploaded to, let's say, Avsim.com ?

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Hi there,wow, those screenshots do look very nice.I'm pretty sure that prominent landmarks will always find happy users in FS, just look at the download numbers for my Everest photoreal textures.How come the discrepancy you mention between download size and HDD space? Have you made seasonal textures?Cheers, Holger

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Hi!,>How come the discrepancy you mention between download size and>HDD space? Have you made seasonal textures?>No seasons here, in Africa ;-)Those 400MB is a plain sum of all 43kB photo textures but when compressed with an intelligent compressor like WinRAR the size shrinks down much.I guess now because I test scenery using less then half of possible target coverage.I have to test also a new idea of RGB->HSL->RGB algorithm to preserve sharpness and get right color. The idea is to do much of processing (enlarging) on separate RGB+ B&W Landsat-7 layers and join them just in the end. Regards, Rysiek

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What size is your source image as a jpg file? You can create a batch mode scenery uploading a jpg, batch, inf file with Resample and ImageTool. The user resaves the jpg as bmp, then runs the batch file to create the scenery.I uploaded an example, Reunion.ZIP to virtualvfr last week but it's not available yet. I'll get back onto them or upload it to Avsim myself. It's based on the scheme demonstrated by Patric Foggarty with his ACT2K.ZIP scenery here on Avsim but updated to use the latest FS2004 SDK tools. You can edit to use with other source image and inf file to minimise the size for up/downloading to not much more than the jpg.The source imagery from Worldwind used in the scenery turned out to be public domain according to their FAQ and no restrictions on using them.Andy

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