[X] My Assistant

[Harkeppler]

Combination of the infrared images of Sol 616 with R4 (red), R5 (green) and R6 (blue) give as a pseudocolor photo after some color enhancement an interesting result:

the blue-gray sharpe edged small stones (probably some vulcanic material) found strawn around the Erebus site look quite different in infrared but not in the visual band. There are at least three destinct infrared signatures giving probably a hint on their origin and chemical composition.

Here, on the left an R2 (red), R1 (blue)-picture is shown with synthetic green chanal according to the visual color taken from an L4L5L6 image and on the right the R4R5R6 picture.

The original Opportunity photos were normalized using a circular mask to reduce the radial loss of brightness to the edges.

This pair can be seen on the right (I am wondering that the thumbnails are not shown in the correct sequence).

The second image couple shows Bounce at Sol 68 in L4L5L6, L2L7 and R2R1 (from left to right with synthetic green in L2L7 and R2R1) for comparison: There is a possibility to make nearly natural looking color composites using the R2 and R1 channels.

This image triple is shown on the left.

(Image processing was done by collegue Mr. Norbert Gasch)

The interesting question is now: Does anyone have an idea what sorts of material this can be at the Erebus site?

Best wishes: Harald

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[edstrick]

Harkeppler: I've gone to sol 616 on the rover web site (not exploratorium) and downloaded all the images for the L and R cameras, and then did several color composites based on different band combinations.

For my composites, I combine bands in the order (RGB) output = bands (abc) in put, where I list the bands in order at the end of the file name, always using long-wavelength as red and short wavelength as blue. I tweek the contrast with "curves" in photoshop to improve contrast on bright surfaces and do an edge-filter sharpening in "LAB" on the "Lightness" image so as not to add noise to the color variations.

The L: 234 image composites infrared,far-red,red as R,G,B and shows little color contrast at long wavelengths in the Left camera. The L: 257 images uses near infrared, Green, and Violet filters as RGB and gives similar results to the more natural color 456 combination, but with more contrast. L: 567 composites Green, Blue and Violet as RGB and shows short-wavelength color variations.

R: 654 composites the 3 right camera infrared channels you said you used and should approximagely produce the same result. I simply do not see the wild color variations of some of the blueberries you've produced. Nor do I see color fringes at the edge of shadows in your image that would result from significant sun movement between filters. (Shadow fringes would be small as the height of the shadow-casting edges is small)

I'm wondering if you may have found a set of images taken at the same sun angle and with the same rover position but on DIFFERENT DAYS, and the wildly colored blueberries could have had dust added or subtracted by wind during the interval between pictures. Otherwise, I'm wondering if your image processing program might have color or brigtness "keyed" on something by accident and generated these bizarre colors. Your Bounce rock images look perfectly reasonable, so I don't understand what may have happened.

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