Rosetta Mars Options

[tedstryk]

It appears Rosetta stuff, including the Mars flyby Osiris data, has hit the PDS. I don't have time to look at it now, but I'm downloading it. http://pdssbn.astro.umd.edu/holdings/

[Bjorn Jonsson]

I have uploaded a new version of IMG2PNG. It has a new command line parameter "-fstretch" which is used to specify how to map the floating point data to 2 byte integers in cases where IMG2PNG doesn't 'know' which parameters are applicable (in these cases it has always used the actual range of the data as described earlier).

For example:

img2png *.img -fstretch0,0.1

This is useful for forcing IMG2PNG to use the same parameters for many images which is necessary when doing color composites. To get a rough idea of which fstretch values might be good first run IMG2PNG without -fstretch and notice a line in the output that looks like this:

Floating point to 16 bit integer conversion: [-0.000023,0.059897] -> [0,65535]

This suggests that -fstretch0,0.06 might be good - or maybe -fstretch0,0.1 to avoid getting saturated areas for images where different and 'brighter' filters might have been used.

The new version is available here.

(By the way, when you run this new version of IMG2PNG the first line you see should read "IMG2PNG v2.02 20120125" - otherwise you have an old version. There were some weird problems a few days ago when uploading and/or downloading IMG2PNG so you should check this just in case).