Sunday, August 24, 2008
Webcams Over Mars!
The ESA has made a call for help with processing the images from the VMC:
Students, teachers, scientists, photographers and the general public are invited to help us process the images, remove artefacts, increase sharpness and interpret what the images show. And if you have success, send us a copy - we'll publish the best submissions right here in the VMC site!
You can get the images from here, and they come with Celestia scripts that allow you to orient yourself. However, the Celestia scripts do not work with the version 1.4.1 that I have. Pay close attention to the fact that the images are supplied as RAW files, not all image processing systems can load them. ImageJ can import them, but remember to type in the image size as 640x 480 (the default is 512x512 which messes the image up).
Up the top left is a raw image from 08-08-08 (click to enlarge), to the right is a processed image. I first imported the image into ImageJ, converted it to BMP format, then imported the BMP into Registax and applied a wavelet correction of 10 in the 5:1 layer, and 30 in the 6:1 layer directly on the single image. Messing with the earlier layers just ends up a mess.
So far I have not been able to get rid of the substantial artefacts that occur in the images (the worst artefact is masked by the bright limb of Mars in the above image). Trying to make minimum stacks or doing frame subtraction has not worked. I need a darkfield of some sort, but with bright Mars in the frame I have no idea how to make one.
Stacking images has not worked either, the images are too soft focus for the automatic stacking algorithm to work (in either Registax of ImageJ), and manual stacking has been painful. I may have to process individual images to get good contrast then stack them.
Still, it is well worth having a go. You might be able to create something like this animation of Mars rotating. Now that would be well worth it.
Update: See my next post, where I have made a stereo image and a rotating animation.
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