martins
Orbiter Founder
1. Introduction
As reported earlier, the next Orbiter release will include support for planet surface terrain. If you have missed it, here is the video I uploaded a while ago introducing a first glimpse of a preliminary terrain implementation:
Pretty good already, isn't it?
11. More things to try
At the moment, woodland areas look a bit dark and don't have much contrast. Apparently, this can be improved by mixing band 4 (near infrared) into the green band 2, because NIR has good contrast for vegetation. I want to try that next.
Also, I want to try histogram-matching the scenes against a global reference (the Visible Earth Blue Marble map that is the basis of the current Orbiter Earth texture). If I can colour-match the high-resolution Landsat maps against the VE map, then I could retain the latter for the lower resolution levels without a visible break when switching to high-resolution patches. Also, mapping against a global reference would ensure that the relative colour balance of the Landsat-generated map would remain consistent across large distances without drift or similar problems.
12. And finally, a plea for help
Writing the scripts for the image processing tasks described above took me about two weeks. But now the work only starts. So far, I have generated a single 16384 x 16384 tile covering 11.25 x 11.25 degrees (the central Europe tile used as an example in this article). The processing time for this tile took about 5 hours, not including the time for downloading the Landsat scenes (the tile is composed of about 100 scenes, each a download of about 300MB). My hard disk is filling up quickly, and I won't have the time, storage capacity and internet bandwidth to do the entire Earth. So I am asking you guys, as future beneficiaries of an improved Earth map, for help. Is anybody prepared to share in the processing work? If you are interested, this is what is required:
If there are any takers who fulfill all criteria and want to help, please let me know. I can then pass you my Matlab scripts and detailed informations. The more volunteers I can gather, the quicker we could end up with a global high-resolution map!
As reported earlier, the next Orbiter release will include support for planet surface terrain. If you have missed it, here is the video I uploaded a while ago introducing a first glimpse of a preliminary terrain implementation:
11. More things to try
At the moment, woodland areas look a bit dark and don't have much contrast. Apparently, this can be improved by mixing band 4 (near infrared) into the green band 2, because NIR has good contrast for vegetation. I want to try that next.
Also, I want to try histogram-matching the scenes against a global reference (the Visible Earth Blue Marble map that is the basis of the current Orbiter Earth texture). If I can colour-match the high-resolution Landsat maps against the VE map, then I could retain the latter for the lower resolution levels without a visible break when switching to high-resolution patches. Also, mapping against a global reference would ensure that the relative colour balance of the Landsat-generated map would remain consistent across large distances without drift or similar problems.
12. And finally, a plea for help
Writing the scripts for the image processing tasks described above took me about two weeks. But now the work only starts. So far, I have generated a single 16384 x 16384 tile covering 11.25 x 11.25 degrees (the central Europe tile used as an example in this article). The processing time for this tile took about 5 hours, not including the time for downloading the Landsat scenes (the tile is composed of about 100 scenes, each a download of about 300MB). My hard disk is filling up quickly, and I won't have the time, storage capacity and internet bandwidth to do the entire Earth. So I am asking you guys, as future beneficiaries of an improved Earth map, for help. Is anybody prepared to share in the processing work? If you are interested, this is what is required:
- A PC with 8GB RAM, running Windows-64 or Linux-64
- Matlab-64 (this is the killer, I suspect. I've written all processing scripts in Matlab. They are not very complex - if somebody wants to convert them to Python or similar, you are most welcome).
- Matlab must understand the geotiffread and geotiffwrite commands. This implies the Mapping toolbox, I think
- A utility to extract files from tar.gz files. Linux users are ok, Windows users can do it for example with 7-zip
- GDAL
- About 100GB HDD space during processing the scenes
- An internet connection that doesn't have problems with downloading ~30GB worth of Landsat data
- A way to upload the resulting map tile so I can pick it up.
If there are any takers who fulfill all criteria and want to help, please let me know. I can then pass you my Matlab scripts and detailed informations. The more volunteers I can gather, the quicker we could end up with a global high-resolution map!
