Vignetting, discussion about methods of resolution |
Vignetting, discussion about methods of resolution |
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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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#2
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Member ![]() ![]() ![]() Group: Members Posts: 156 Joined: 18-March 05 From: Germany Member No.: 211 ![]() |
I made a minor modification to the program. I don't know whether that will make any difference to the problem that you encountered James. Just try it out and tell me what the result is. Version 2.0.1 can be found here: AntiVig
Michael |
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#3
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![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 ![]() |
QUOTE (MichaelT @ Nov 16 2005, 07:47 PM) I made a minor modification to the program. I don't know whether that will make any difference to the problem that you encountered James. Just try it out and tell me what the result is. Version 2.0.1 can be found here: AntiVig Michael It works! ![]() ![]() ![]() Thanks Michael, Cheers, James -------------------- |
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#4
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Member ![]() ![]() ![]() Group: Members Posts: 156 Joined: 18-March 05 From: Germany Member No.: 211 ![]() |
QUOTE (jamescanvin @ Nov 19 2005, 02:43 AM) ![]() ![]() Well, I had forgotten to eliminate one little command: WAIT, 0.00001 That command makes the program wait for 1/10000 of a second. I had to slow down the program on my comupter on purpose, when running in IDL. Otherwise it always crashed, probably due to some ram access conflicts. That wait-command is within a loop, resulting, theoretically, and on a Windows system obviously practically, in an overall delay of about 1/200 of a second. Why that causes the program to be that slow on a Mac is quite surprising. Sorry for that. In the end, all I had to do was to delete these lines. You can still find them in the code that I posted further above. Have a nice weekend! Michael |
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