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Vignetting, discussion about methods of resolution
Tman
post Aug 24 2005, 07:37 AM
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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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MichaelT
post May 5 2006, 11:46 AM
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After a long, long time I am currently developing a new version of my anti vignetting tool, version 3. Again, it is based on IDL and can be used with RSI's Virtual Machine. See earlier this thread.
It is not complete, yet. The "save file" buttons are not fully functional up to now (you can't save). But, I want to give you a preview of what to expect during the next weeks. You can already play around and test it and tell me about any bugs that you find.


The program is now faster due to a much improved and simpler de-vignetting routine. Also, you can do more adjustments than in the previous versions.

Other improvements:
- You can open as many files as you like and change between them during processing (pull-down-menu).
- A '+' or '-' before each file name indicates the processing state (with or without de-vignetting).
- After processing simply choose "save all" and the program will automatically save all the files in folders designated by you.
- "Save all" will open a window with a list of all files and their current state of processing. It is planned to enable you to set output-folders for each file or copy a certain output-folder-name to a selection of files. After hitting "save", all currently processes images will be saved one after another. This could take some time as the program does not keep the whole file in its memory but just a smaller version. So it will read each file again, do the de-vignetting and save it to the destination folder.
- Like in the previous versions you can choose either jpeg or 16-bit-tiff output (or both). Do you need any other file types (png)?
- You can draw an area in the image window which will be used for the de-vignetting (by clicking with the left mouse button, set up to 64 points). Clicking close to an already present line will insert a new point. These points can be relocated by holding the left mouse button and moving the mouse. You can delete them by double-clicking (except the one in the lower left corner).
- The selcted area can be copied from one image to another.
- The de-vignetting of anaglyphs also removes the green/blue - red gradient wich often causes dark borders between image even though they vignetting has been removed.
- You can also adjust the brightness of the image (shift the whole color range or with a multiplicative factor) and the amount of vignetting.
- Clicking and holding with the right mouse button will show the unprocessed image if you have already processed it. This click will also select a line (x direction) the brightness values of which will be shown in the left hand window when changing the brightness and de-vignetting settings. That way you can optimally adjust the a-vig values.
- The histogram of the image is also shown after each change. Even though the image is shown with a pixel value cut-off of 255 then actual histogram is shown in the histogram window. Saving the file as 16-bit-Tiff will retain even those pixels which are brighter than 255.
- Moving the mouse cursor over a button will show you its function (help button is still missing).
- you can choose the type of the image (gray-scale, anaglyph, RGB) manually, though it is determined automatically when loading it. Changing the type can have the benefit that you can move the sliders for the de-vignetting and brightnes adjustment either independently or together. before saving you should set it back to the actual type.

Things I also want to implement is output of the de-vignetting or vignetting mask.

There are certainly things that I forgot to mention. Simply try it out or ask me.

So this is the time now to tell me your wishes or worries or both smile.gif

The program is located here: http://www.muk.uni-hannover.de/~theusner/mars/anti_vig_n.sav

Like in the previous versions, you must not, under all circumstances, change its name biggrin.gif

Have fun playing around with it!

Michael

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Posts in this topic
- Tman   Vignetting   Aug 24 2005, 07:37 AM
- - Nirgal   Hi Tman, mathematically, we can describe vignetti...   Aug 24 2005, 11:29 PM
- - Tman   Hi Nirgal, probably you're right and it's ...   Aug 25 2005, 11:26 AM
|- - Nirgal   Thanks Micheal, hopefully I will find the time to...   Aug 25 2005, 08:46 PM
|- - Tman   QUOTE (Nirgal @ Aug 25 2005, 10:46 PM)...no n...   Aug 25 2005, 09:29 PM
|- - Tesheiner   QUOTE (Tman @ Aug 25 2005, 11:29 PM)Guess I...   Aug 26 2005, 06:42 AM
- - MichaelT   Hi Tman, I tried it using "Fast Fourier Tran...   Aug 25 2005, 12:42 PM
- - Tman   Hi Michael, best we would talk about it in German,...   Aug 25 2005, 02:17 PM
|- - MichaelT   QUOTE (Tman @ Aug 25 2005, 02:17 PM)Hi Michae...   Aug 25 2005, 04:39 PM
|- - Nirgal   QUOTE (MichaelT @ Aug 25 2005, 06:39 PM)Proba...   Aug 25 2005, 05:16 PM
|- - MichaelT   QUOTE (Nirgal @ Aug 25 2005, 05:16 PM)Hi Mich...   Aug 25 2005, 05:59 PM
- - Tman   Yeah sounds really good so far That would be fant...   Aug 25 2005, 08:38 PM
- - MichaelT   Nirgal, I finished the commenting of my program to...   Aug 26 2005, 05:57 PM
- - MichaelT   I have now modified the anti-vignetting-program (u...   Sep 14 2005, 05:49 PM
|- - dilo   WOW! MichaelT, I think would be really GREAT t...   Sep 14 2005, 06:38 PM
||- - mhoward   QUOTE (dilo @ Sep 14 2005, 06:38 PM)WOW! ...   Nov 11 2005, 04:09 PM
||- - dilo   QUOTE (mhoward @ Nov 11 2005, 04:09 PM)If the...   Nov 13 2005, 08:02 AM
|- - Bob Shaw   MichaelT: Do you think your anti-vignetting app c...   Sep 14 2005, 06:53 PM
|- - MichaelT   QUOTE (Bob Shaw @ Sep 14 2005, 06:53 PM)Micha...   Sep 14 2005, 07:39 PM
|- - Bob Shaw   QUOTE (MichaelT @ Sep 14 2005, 08:39 PM)Bob, ...   Sep 14 2005, 08:43 PM
- - djellison   I'm guessing there's no flatfield or darkf...   Sep 14 2005, 07:03 PM
|- - tedstryk   I usually try to make a blank image with my digita...   Sep 14 2005, 07:32 PM
- - MichaelT   Hi, I put an updated version of the anti-vignetti...   Oct 24 2005, 04:30 PM
|- - Tesheiner   QUOTE (MichaelT @ Oct 24 2005, 06:30 PM)Anywa...   Nov 1 2005, 02:25 PM
- - jvandriel   Tman, what I mean to say with those lines is the ...   Nov 1 2005, 10:31 AM
- - Tman   You're right Jvandriel, it's for both very...   Nov 1 2005, 11:59 AM
- - djellison   I dont mind it running in IDL, but I would really ...   Nov 1 2005, 04:00 PM
- - MichaelT   QUOTE (djellison @ Nov 1 2005, 04:00 PM)I don...   Nov 1 2005, 04:22 PM
- - MichaelT   I just put online Version 2.0, now with batch proc...   Nov 1 2005, 05:45 PM
- - Tman   Hi Michael, Tried the batch processing just with ...   Nov 1 2005, 06:58 PM
- - jvandriel   Michael T, today I used for the first time your a...   Nov 3 2005, 03:20 PM
- - Nix   I'm starting to use your tool too, looks prett...   Nov 3 2005, 07:12 PM
- - MichaelT   Hi Michael, it would indeed be very nice if someo...   Nov 13 2005, 06:17 PM
|- - jaredGalen   I would be interested in giving it a go. I made a ...   Nov 13 2005, 06:49 PM
|- - MichaelT   QUOTE (jaredGalen @ Nov 13 2005, 06:49 PM)I w...   Nov 14 2005, 06:12 PM
|- - jaredGalen   Wow, okay. Looks like I have my work cut out for ...   Nov 14 2005, 06:33 PM
- - slinted   Michael, thank you for sharing the code to this ap...   Nov 14 2005, 11:15 PM
|- - jaredGalen   QUOTE (slinted @ Nov 15 2005, 12:15 AM)Jared,...   Nov 15 2005, 09:05 AM
- - jamescanvin   How long does this program take to run for you guy...   Nov 15 2005, 02:50 AM
|- - MichaelT   QUOTE (jamescanvin @ Nov 15 2005, 02:50 AM)Ho...   Nov 15 2005, 10:04 AM
- - Tman   The same to me - 5 seconds. My PC system runs 2,4...   Nov 15 2005, 10:51 AM
- - jamescanvin   Hmm, 5 seconds eh, that's a bit quicker than 5...   Nov 15 2005, 01:34 PM
- - Nix   no mac, but 3 seconds, although it might well be a...   Nov 15 2005, 05:28 PM
|- - jamescanvin   QUOTE (NIX @ Nov 16 2005, 04:28 AM)Hope you f...   Nov 15 2005, 11:13 PM
- - MichaelT   I made a minor modification to the program. I don...   Nov 16 2005, 08:47 AM
|- - jaredGalen   Hi, I haven't a much of a chance to do any cod...   Nov 16 2005, 01:38 PM
||- - MichaelT   QUOTE (jaredGalen @ Nov 16 2005, 01:38 PM)Hi,...   Nov 16 2005, 03:12 PM
||- - Nirgal   Micheal, I just like to say thank you for sharing...   Nov 16 2005, 08:36 PM
||- - MichaelT   QUOTE (Nirgal @ Nov 16 2005, 08:36 PM)Micheal...   Nov 17 2005, 08:45 PM
|- - jamescanvin   QUOTE (MichaelT @ Nov 16 2005, 07:47 PM)I mad...   Nov 17 2005, 03:10 AM
|- - jamescanvin   QUOTE (MichaelT @ Nov 16 2005, 07:47 PM)I mad...   Nov 19 2005, 02:43 AM
|- - MichaelT   QUOTE (jamescanvin @ Nov 19 2005, 02:43 AM)It...   Nov 19 2005, 08:05 AM
- - jvandriel   MichaelT, I just downloaded Anti_Vig 2.0.1, but w...   Nov 18 2005, 12:41 PM
|- - MichaelT   QUOTE (jvandriel @ Nov 18 2005, 12:41 PM)Mich...   Nov 18 2005, 01:49 PM
- - Tman   Hi Jvandriel, I guess you renamed it as "Ant...   Nov 18 2005, 01:44 PM
|- - MichaelT   QUOTE (Tman @ Nov 18 2005, 01:44 PM)Hi Jvandr...   Nov 18 2005, 01:54 PM
- - MichaelT   Would you like me to include the version number in...   Nov 18 2005, 02:04 PM
- - Tman   Hi Michael, just reply overlap. Regarding version...   Nov 18 2005, 02:09 PM
- - jvandriel   MichaelT and Tman, thanks for the advice. I did i...   Nov 19 2005, 02:04 PM
|- - MichaelT   QUOTE (jvandriel @ Nov 19 2005, 02:04 PM)is i...   Nov 24 2005, 05:40 PM
- - MichaelT   After a long, long time I am currently developing ...   May 5 2006, 11:46 AM
|- - hortonheardawho   Hi Michael, I have been interested in your anti-v...   Jun 9 2006, 10:16 PM
- - hortonheardawho   Doesn't look like Michael is monitoring this t...   Jun 11 2006, 07:58 PM
|- - MichaelT   QUOTE (hortonheardawho @ Jun 11 2006, 07...   Jun 12 2006, 05:12 PM
- - DonPMitchell   Very cool work, Michael. I know in a mathematical...   Jun 12 2006, 06:07 PM
|- - Airbag   QUOTE (DonPMitchell @ Jun 12 2006, 02:07 ...   Jun 13 2006, 02:47 AM
||- - helvick   QUOTE (Airbag @ Jun 13 2006, 03:47 AM) Th...   Jun 13 2006, 12:53 PM
|- - MichaelT   QUOTE (DonPMitchell @ Jun 12 2006, 06:07 ...   Jun 14 2006, 05:06 PM
|- - DonPMitchell   If they measured the camera response, then that is...   Jun 14 2006, 05:42 PM
- - jrdahlman   Is this anti-vignetting program specifically for M...   Jun 29 2006, 07:43 PM
|- - MichaelT   QUOTE (jrdahlman @ Jun 29 2006, 07:43 PM)...   Jul 3 2006, 06:03 PM
- - edstrick   The Voyager (mariners, viking) cameras have other ...   Jul 4 2006, 09:51 AM
- - jrdahlman   Sorry for the delay. My website requires me to upl...   Jul 5 2006, 04:47 PM
|- - MichaelT   QUOTE (jrdahlman @ Jul 5 2006, 04:47 PM) ...   Jul 6 2006, 12:37 PM
|- - ugordan   QUOTE (jrdahlman @ Jul 5 2006, 05:47 PM) ...   Jul 6 2006, 01:01 PM
|- - MichaelT   QUOTE (jrdahlman @ Jul 5 2006, 04:47 PM) ...   Jul 6 2006, 05:59 PM
- - um3k   Another problem is that Voyager images exhibit a l...   Jul 6 2006, 01:49 PM
- - um3k   jrdahlman, these websites may come in handy for yo...   Jul 6 2006, 08:06 PM
- - jrdahlman   Oh, I know that you can download all the images. I...   Jul 6 2006, 08:59 PM
|- - um3k   QUOTE (jrdahlman @ Jul 6 2006, 04:59 PM) ...   Jul 7 2006, 12:57 AM
- - edstrick   Playing with Voyager 1 wide angle images, I found ...   Jul 7 2006, 11:37 AM
- - jrdahlman   I would like to point out that the program um3k...   Jul 10 2006, 06:19 AM
- - edstrick   Dark current images are those taken with zero expo...   Jul 10 2006, 09:42 AM


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