[X] My Assistant

[hubdel11]

the DIRS have posted 2 new mosaics on their site :
http://www.lpl.arizona.edu/%7Ekholso/Titan...3K_big_ster.jpg
http://www.lpl.arizona.edu/%7Ekholso/Titan...Apr15_gnom_.png

[Phil Stooke]

Dilo - only the worst noise is removed, plus other artifacts such as a faint pattern of vertical one column wide stripes, or occasionally a missing line of pixels. So this is not enough to negate the later sharpening. So - first the image is cleaned up as much as necessary in that way. The images are then enlarged by some integer factor, 2 or 3 or 4, using some higher order interpolation. The registration is done by limb fitting (on satellite images) or other major feature fitting on other types of image - matching the centers of the blurred limbs in the enlarged images.
They are then stacked and merged.

As for contrast enhancement... I was generating images which showed the best combination of large and small features (sharp craters and broad albedo markings) for mapping purposes. True photometric fidelity is lost in these images but features of all scales are shown at once. Each separate image was optimally enhanced before making the composite. I devised a method in which a single image was duplicated 4 or 5 times, and each version manipulated differently - different contrast settings and high pass filtering at different scales to optimize features of different sizes - and had its artifacts corrected or removed (e,g. limb artifacts in the high pass filter versions). These different versions were then merged. The Dione image is a typical result.

Phil