Vignetting, discussion about methods of resolution |
Vignetting, discussion about methods of resolution |
Aug 24 2005, 07:37 AM
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#1
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Member Group: Members Posts: 877 Joined: 7-March 05 From: Switzerland Member No.: 186 |
Hi Nirgal and all, I would like to discuss about vignetting and methods of resolution for it. I'm mainly interested in mathematical methods that could automatically calculate and adjust the right grey value for each pixel in a single picture.
My current method works with more or less transparent layers over the original picture that so roughly are able to balance the grey values. A perfect layer have to be the exact inverted brightness difference of each picture with this shadow effects. This method is very effective if you get the correct inverted values. These shots of the Mars sky come nearly at such a perfect mask, but not always. And of course the center of the pictures lose much of theirs original brightness/luminance sadly. I have in mind a mathematical method that can adjust each grey value in a pic in order to obtain a completely balanced brightness over the entire picture. But I'm not in the position to reach that. I only know one have to start with the calculation of the grey values in the center of the picture. In the center are quasi the reference values of the whole picture, if I'm correct. Is there a possibility (mathematical method) to get (roughly) the same brightness and luminance like in the center over the whole picture from the MERs? Greetings, Peter -------------------- |
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Aug 25 2005, 11:26 AM
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#2
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Member Group: Members Posts: 877 Joined: 7-March 05 From: Switzerland Member No.: 186 |
Hi Nirgal, probably you're right and it's impossible with Navcam pics. Btw. dont you fancy to dye my sol 581 pan again?
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Aug 25 2005, 08:46 PM
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#3
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Member Group: Members Posts: 713 Joined: 30-March 05 Member No.: 223 |
Thanks Micheal,
hopefully I will find the time to do do the coding soon (I'll never know whether I spent more time with image processing or with coding the tools that in turn help with the image processing both is a lot of fun.. to see mathematics in action, turning formulas to living shapes & colors QUOTE (Tman @ Aug 25 2005, 01:26 PM) Hi Nirgal, probably you're right and it's impossible with Navcam pics. Btw. dont you fancy to dye my sol 581 pan again? yes it's tempting, but in this case I think I'll probably wait for the full summit panorama with all the multi-filter true color frames ... no need for artificial colors then However I do plan a coloring of (part of) the sol 581 nacvam panorama (in particular the scene with the large "dust-tornado", IMHO one of the all-time greatest shots in space exploration at all ! Heck, even strom chasers on Earth would be proud of such a shot, showing this F4-tornado sized monster within a mountain scenery... but here we managed to capture this breathtaking moment on another planet !! ... what a beautifully convincing impression of a the "dynamic" nature of the planet mars ... Oh, I'm getting carried away ... ... so unless we will catch a comparatively large & scenic DD also with the pancam I simply have to somehow coloring this unbelievable view.. It will be difficult though, because the high amount of contrast stretching in this series of pancam images (that leaves little play for manipulating the histogram) makes coloring process all the more difficult (despite the fact, that there is only one "filter" to synthesize the colors from |
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Aug 25 2005, 09:29 PM
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#4
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Member Group: Members Posts: 877 Joined: 7-March 05 From: Switzerland Member No.: 186 |
QUOTE (Nirgal @ Aug 25 2005, 10:46 PM) ...no need for artificial colors then However I do plan a coloring of (part of) the sol 581 nacvam panorama (in particular the scene with the large "dust-tornado", IMHO one of the all-time greatest shots in space exploration at all !... Maybe it shows some artifacts, but it is also simply a very nice matter of Mars artwork to me! It looks partly like a real and high-quality canvas! Guess I'll this sol 581 Navcam pan still complete to a 360 degree full res. pan - but so far in a left pic lack two parts. It would be nice to see the whole scene with all the features and DDs around and always coming back to the monster DD. I mean too this scene is quite special. -------------------- |
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