Re: [APML] OT: Tricolor Mars Images

["joe" <jmize@svic.net>]

Chuck, and all;

     This is the image which forced me, and still does, to ask, "Why do all
the rocks in this image have sharp, angular edges and corners?"  Shouldn't
they be soft and rounded with all the blowing sand and dust over
time???...joe  :)


"May You Go Among The Imperishable Stars"

Joe Mize:     jmize@svic.net
StarFields Observatory   http://www.svic.net/jmize
Chiefland, FL    29:24'33.4"N    82:51'37.7"W
Moon Phase:     http://tycho.usno.navy.mil/cgi-bin/phase.gif

----- Original Message ----- 
From: "Chuck Vaughn" <aa6g@aa6g.org>
To: <astro-photo@seds.org>
Sent: Monday, February 02, 2004 5:54 PM
Subject: [APML] OT: Tricolor Mars Images


> List,
>
> If the weather is lousy like it is here and you can't do any
> astrophotography but you'd like to do some image processing..... How
> about some tricolor images from Mars?
>
> I've been looking the raw images from the MERs trying to figure out how
> to make color images from the Pancam multispectral images. I finally
> found what the wavelengths of the various filters in the camera are.
> The file name of each image contains the filter used. It is located in
> the 3rd and 4th characters from the end of the name, ...L1M1.jpg,
> ...R2M1.jpg for example. This means left 1 and right 2. There are 8
> interference filters on each side and they are not the same. The right
> is mostly IR filters and the left mostly visible light filters. The
> bandwidths are between 15 and 30nm. Here's a list of the filters:
>
> L1 - 719nm broadband filter     R1 - 440nm blue stereo
> L2 - 753nm red stereo           R2 - 754nm red stereo
> L3 - 673nm                      R3 - 803nm
> L4 - 602nm                      R4 - 864nm
> L5 - 535nm                      R5 - 903nm
> L6 - 483nm                      R6 - 933nm
> L7 - 440nm blue stereo          R7 - 1001nm
> L8 - 440nm ND5 solar filter     R8 - 880nm ND5 solar filter
>
> Obviously there are a lot of ways to make a color image. Few images are
> available from all the non solar filters. I've had some success using
> the following combinations for RGB:
>
> R = Average of L3 & L4
> G = L5
> B = Average of L6 and L7
>
> This doesn't give a perfect color image. Some kind of color calibration
> has to be applied which I don't have. So far I've found the images to
> be too green and too blue. Photoshop curves can be used to adjust that.
> Here's an example:
>
> http://www.aa6g.org/Images/L3L4_L5_L6L7_color_image.jpg  (240KB)
>
> If you want to make stereo images use L2/R2 or L7/R1. There are lots of
> raw images that have not been processed for public distribution so
> there's more to see than the press releases on the web site.
>
> In case you need it here is the location of the raw images:
>
> http://marsrovers.jpl.nasa.gov/gallery/all/
>
> Have fun!
>
> Chuck
>
> ps. I also made a partial stereo anaglyph panorama from Spirit images
> (10 image mosaic) that is much higher resolution (about 8000 x 1100
> pixels) than what is available on the MER web site. I don't have enough
> web bandwidth at my ISP to allow hundreds of downloads of the 1.2 MB
> file. If someone who doesn't have a bandwidth limitation would like to
> make this available to the group, e-mail me privately and I'll e-mail
> it to you so you can post it.
>
> _______________________________________________
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>

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