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HiRISE Expert Question: EDR/RDR with more than 8 bit dynamic range, Is the 14-to-8 bit LUT always applied on board or is LUT optional
Nirgal
post Jan 21 2009, 07:15 PM
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Is there any way to obtain the original 14-bit dynamic range resolution of the HiRISE instruments from the raw data, at least for some images ?
or is this always converted to 8-bit already on the spacecraft ?
After reading the RDR/EDR specs it seems that the on-board application of 14-to-8 bits reduction Lookup-Tables (LUT) is not obligatory but may be an optional intrument setting that could be commanded individually for each image (just as other settings like the "pixel binning").

(see PDS parameter "MRO:LOOKUP_TABLE_TYPE" in the "INSTRUMENT_SETTING_PARAMETERS" parameter group.)

So the question is: are there some images taken either without the LUT, or a LUT that preserves more than 8 bits ?

This would be very interesting especially with the large spatial range of the camera that covers Mars scenes with an extremely large dynamic range from deep shadows over black basalt to sun facing icy slopes.
This is not to say that the availiable DRA adjustments (e.g. IAS-viewer's auto-DRA feature) already do a very good job even with only 8-bits smile.gif But nevertheless I'm curios if higher-than 8 bits per-pixel data could be obtained in any way ...
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