Reprocessing Historical Images - II, Restoring images from antiquated and/or poor quality sources |
Reprocessing Historical Images - II, Restoring images from antiquated and/or poor quality sources |
Feb 4 2009, 11:48 AM
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#46
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
So i need more time to optimize the code and try to ignore level changes due to isolated pixels. So it's something similar to deblocking algorithms for MPEG video decoders. It's somewhat of a black art - you ignore too many "isolated" noise pixels and all of a sudden you realize you're starting to destroy valid details too... EDIT: That sort of thing could be helpful with problems described in this thread, namely color banding after massively enlarging a Titan image. If done with 16 bit color, dithering down to 8 bits could remove the banding effects. -------------------- |
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Feb 17 2009, 09:53 PM
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#47
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
I have completed the Mariner-7 Meridiani mosaic. Please note that due to the nature of the images, certain portions of each frame are better than other areas. The first set is the complete black and white mosaic. The second set is a combination of RGB color with two color (red-blue with green synthesized by averaging the two and green-blue with red synthesized by altering green images to resemble red). The images were then tweaked to minimize differences stemming from different filter sampling. The right hand image is the RGB image. Please note that the "Red" is more of a far orange than a true red. While the wide angle cameras on Mariner 6 and 7 constantly cycled through their filters, this is the only mosaic (other than late far encounter data) in which there is significant overlapping colors.
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Feb 18 2009, 01:37 AM
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#48
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
Ted -- is it true that Endeavour Crater is resolved in these mosaics?
-the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Feb 18 2009, 01:51 AM
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#49
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Senior Member Group: Moderator Posts: 3431 Joined: 11-August 04 From: USA Member No.: 98 |
I can see a slight darkening where Endeavour is, I think. The craters in the neighborhood which are either slightly larger or more distinct all show up quite well.
It's a great view. |
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Feb 18 2009, 02:36 AM
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#50
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Yes, it is a barely detectable smudge. However, while the Mariner 7 view is in my estimation prettier, Mariner 6 got a better view of this region and it is much clear in this mosaic.
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Feb 18 2009, 07:58 PM
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#51
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Solar System Cartographer Group: Members Posts: 10182 Joined: 5-April 05 From: Canada Member No.: 227 |
Yes, the trio of craters, with Endeavour at the north end, is clearly visible.
Here's another historic image: It's a Mariner 9 image of Mars taken during approach. The planet is covered in a rover-killing dust storm (good job there were no rovers present at the time). Contrast enhancement has revealed the Valles Marineris full of dust. The south polar cap is visible as well as a few other features. Doesn't it look like Titan? Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 18 2009, 09:29 PM
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#52
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Yes, it does, especially in color. The image on the left is a true tri-color, the image on the right is only colorized.
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May 23 2009, 11:16 PM
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#53
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Junior Member Group: Members Posts: 47 Joined: 27-December 07 Member No.: 3991 |
Hi, thanks for these pics, love them.
I had to have a go at an oldie myself. I know its been done before. What do you think? False colour Mariner 4 image |
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May 24 2009, 02:45 AM
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#54
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
What did you use as your data source?
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May 24 2009, 09:35 AM
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#55
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Junior Member Group: Members Posts: 47 Joined: 27-December 07 Member No.: 3991 |
The sources were all from the net from various places, I was trying to find all the Mariner 4 frames, which I eventually all found on a NASA cd somewhere, but prior to that, there were a few versions of the same image at various websites on my PC, I didn't know which was the original until I went to NASA and got the lot. Anyway, the other versions, perhaps one from one of your own sites, if you have done this before, were different contrast levels, one was bw way stretched, to see the max extent of the atmosphere.
The filenames weren't changed much, MA4-01e.gif become MA4-01d.gif on another example and a MA4-01h.gif as well. So I played around with making different bands from the one image, using the contrast levels to separate them. I used a mix of the different contrast versions from various paces on the web, I'm sorry, I can't remember from where, and the original image MA4-01e.gif from NASA. edit: I had a look around the hd and found, The original NASA filename is Ma4-01E.gif The high contrast version is m04_01h.gif, it's a bit different. ? a replaced with 0. Did a google search for m04_01h.gif Found it and m04_01d.gif at http://library.thinkquest.org/19455/marine...age_gallery.htm and looking at it, I have no idea how they got that from the original. There isn't any detail about how the images were made. Perhaps the person that made it, did it from a print out of the original numbers. Do those files of the numbers for the images exist anywhere accessible to the public. It would be like having a RAW file. All I had to play with is the NASA gif and what I found elsewhere. I found another image the same as m04_01d.gif It is named nssdc_MR_Mrnr_m04_01d.gif Well, whomever did the job on those numbers did it pretty good, (drool) Google could not find a nssdc_MR_Mrnr_m04_01d.gif nor a nssdc_MR_Mrnr_m04_01h.gif I have no idea where nssdc_MR_Mrnr_m04_01d.gif came from. But it is the same image as m04_01d.gif from thinkquest. I'll try and reproduce what I did. Edit again: I put all the images I found on the same page as the colour pic. http://www.vk3ukf.com/Mars/Mariner/Mariner...one_page_01.htm |
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May 24 2009, 12:17 PM
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#56
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
I think they come from http://nssdc.gsfc.nasa.gov/imgcat/html/obj...ge/m04_01d.html
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May 24 2009, 12:36 PM
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#57
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Junior Member Group: Members Posts: 47 Joined: 27-December 07 Member No.: 3991 |
Yes, that's the d version alright, the h version looks like a top end stretch of the numbers, a variation of 1 in brightness stretched in that area.
I recently found python code, had a go and made a XP gui for Bill Allen's PDS *.img file display, save and header scripts. I found that manipulating images in python is easier than using delphi 7, but I still need delphi for the gui. I liked the LIDAR imaging, if you played those in a movie, is it like a waterfall display, such as I have seen on some audio and HAM software. Edit: thanks for the URL, I updated the references. So what did I make?, is it a good mix or a bit of a furphy? |
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May 24 2009, 03:56 PM
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#58
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Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
Picture #1
Image source: NSSDC - 35 mm microfilm Used scanner: Drum scanner - CROSFIELD CELSIS 6250 CASC Used scanner: Drum scanner - CROSFIELD CELSIS 6250 CASC Processing: Image - scanned, contrasted and blurred Inset - original digital data with contrast enhancement factor four Picture #11 Inset - original digital data. -------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
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May 27 2009, 06:42 PM
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#59
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Junior Member Group: Members Posts: 47 Joined: 27-December 07 Member No.: 3991 |
Hi Peter59,
nice images. A 35mm film archive. Can these still be obtained? Are they consisting of each image processed in several different ways? Is this the original archive of all image data products from the spacecraft data? |
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Jun 30 2009, 08:12 PM
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#60
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Member Group: Members Posts: 655 Joined: 22-January 06 Member No.: 655 |
Not strictly reprocessing, more updating...
I recently stumbled across the familiar Voyager montage of Saturn and selected moons that was almost omnipresent in periodicals and textbooks in the early eighties (very nostalgic!) Attached are the original, and my updated version using Cassini data. |
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