I figure that it is time for another thread like this. I still find it astonishing to see the versions of a lot of images that are reproduced over and over again. For example, this is the last mosaic of Triton taken before the close encounter began. The version on the Planetary Photojournal is on the left, my version on the right. Clearly, this image was produced as part of the "instant science" campaign. They did a superb job getting images to the public in a speedy manner, but they are extremely rough, since the team was busy running the spacecraft. However, it is this version that keeps being recycled. Worse, the version on the photojournal is clearly scanned from a printed copy, causing further degradation.
WOW! Love it.
More!
Got any tips or tutorials with before and after pix?
I've been trying to work with the MEX VMC images and have found it pretty rough going.
(I got adjustment layers and other stuff all over the place).
-Mike
I can't get enough of this kind of thing. Thank you.
What is the source of your Triton data Ted as compared to the scanned print you are comparing it to?
Wow that Proteus result is stunning! So much sharper and much more detailed!
Hi Ted
I have to agree what Stefan says. I think the normal Images does not contain so much detail. Its easy to say it for Proteus, since there is only one image where this moon is bigger on an image than about 100-150 pixels. Its the frame number C1138920.
A simply Conversion of the PDS Data to the png format without any change is here:
http://www.bernd-leitenberger.de/download/C1138920.png
Proteous is very dark, nearly at the same level as the background, therefore you have much noise on the picture. The planetary photojourna made out of this noise structures and your pictures made much more details out of it - but i think they are not in the original image.
I think you should test your method and validate the results. You can do this by example, if you use the same method with an old viking or mariner 9 image and compare it with an image with better resolution by mex or you work on voyager iamge of the moons of saturn and compare with an cassini image. Without validation, that you really show hidden details and not create only new details from noise, the images are nice to watch but scientific worthless.
Here is an example of the sequence.. Chirin, the image you posted is not calibrated. I tested my methods extensively using Voyager Saturn data since I had Cassini data to verify accuracy. The detail is very consistent. I wasn't confident of it until I saw the features in the second closest set, which is a multi-frame sequence that I could stack to reduce noise.
Would another means of validating the image be to plausibly explain the 'brushstrokes' as expected surface wrinklage froman object on cusp of being sufficiently massive to spherize itself ??
My first reaction to the 'brushstrokes' was along those lines, but since it has come up as possibly an artifact, well, we need to discuss them. I still think they are plausibly an expected surface feature on an object in the Proteus size/temperature/composition orbiting close to Neptune, but I am eager to hear what others think they are.
I recall the picture being deliberately underexposed as the capabilities of Voyager II to implement the image motion compensation at the time the picture was shot wasn't feasible, hence to get an unblurred picture, they had to shoot a quick exposure.
I was not aware a series of images were taken of Proteus, nice surprise and a big 'attaboy' for having them here for us!
If you notice, there aren't interpretable features on the left side except at the very top. There are tantalizing hints, but much less can be seen.
Tasp, it is pretty straightforward. When you process an underexposed image, when you deconvolve an out of focus image, or when you desmear an image, high contrast details are recovered but low contrast ones that are simply not in the data are lost. Hence, high contrast detail is sharp, and low contrast detail is lost. Add to that the fact that in some cases, particularly when you are dealing with an underexposed image, some lower contrast detail can be recovered by binning it 2x2 or even 4x4. However, binning costs spacial resolution. Hence, lower contrast details that are recovered appear amorphous when compared to the high contrast details. That is why the limb looks sharp, as does the area where the illumination angle makes for nice shadows. However, the features look amorphous on the left side because there are no high-contrast features (in other words, no shadows). That is what creates that brush-stroke like effect.
Here is an example of a mosaic that combines a lot of things. The lower part of the mosaic uses nice, sharp frames. The portions toward the terminator are from two smeared frames. The one on the left-hand side is severely smeared. The brush-strokey texture begins to emerge. The night side regions, being severely underexposed, are affected even more. This mosaic, especially the nightside coverage, was very well received at this year's LPSC.
More related to my original post, here is the Triton approach sequence I put together. The upper quarter or so of the last image is reprojected from earlier frames as it was clipped. Some of the sets are underexposed, which leads to some of the effects discussed earlier.
Great work, Ted! I especially like the Triton color sequence. It's a fascinating moon.
Thanks. I eventually hope to do more of the images, both before and after closest approach.
It is there, and I have brightened it in this version. It may have been lost in the 16-to-8 bit conversion. I have stretched it in this version. Stefan, you have every right to your opinion, but beyond some faint light and dark features, I am not sure what features are on the left part of my version of the image. All I see is a small, faint possible crater in the center and a long dark albedo feature stretching across the disk from top to bottom (has been interpreted as groves, but that is a guess). Given how well the features matched up in the common areas between the images, I decided not to suppress other little mottlings in the limb area any more than I would the overlapping areas. Stefan, what is frustrating is that you are not responding at all to my explanation of how I did it.
I would agree - Stefan, you're not reading what Ted has posted in response to your initial scepticism and doubts. To be honest, my patience would have evaporated long ago.
This is another image that I find interesting. I have always wondered why some areas, even under low solar illumination, look very smooth on a fine scale, while some areas do not. I had always faulted the image data, but given the smoothness of portions of some of the small Saturnian moons, I have come to question that.
This discussion is obviously going in the wrong direction, so this will be my last contribution.
I must agree with Stefan's skepticism. Ted's images have been bothering me for sometime. I do not want to offend him as I admire his work and enthusiasm, but Ted, as I have told you in our private conversation it is sometimes better to leave the noise removal to the human brain. Your method removes real information from well exposed images and adds non-existant information to noisy ones and it could be misleading for people outside this forum. Your images are already great without noise removal.
Stefan, I discussed this earlier in the thread, but I will add that I convert the images to 16-bit before binning to reduce damage.
Tayfun, the Mariner 6 and 7 images are a very different breed in there are some areas of the images that are totally saturated in analog and are therefore only available in the undersampled digital format, which makes part of the images better than others. I think that is what you are getting at there, but if not, I would appreciate your showing me (I am not saying that to be sarcastic - I literally mean it, I respect your work and knowledge, and I would like your input). However, on some images, there is the fact dealing with desmeared/deconvoluted and underexposed images can lead to a sort of terracing effect is something I have worked to find ways to get rid of that did not wipe out the high contrast details as well. As a result, low contrast features are less distinct than high contrast features. I never thought of someone thinking this is real.
Ted, let's take your Proteus image as an example, due to its low DN values and high noise ratio there is a mathematical limit to the information that this image can hold. When I look at the NASA version my brain realizes that this is a noisy picture and interprets it accordingly. When I look at your version which looks perfect and as if taken under ideal conditions, my brain interprets all the details as real and that is the problem. Not only the real craters, but also any chance alignment of light and dark pixels looks like real features.
Also some of the real information that our brains would have no difficulty seeing it from the noisy background is also lost in the softening process. Try removing noise from Cassini SAR images, you will not be able to see many of the fine details.
This is a little bit like restoring historical artefacts to the limit that will make them look newly made. You will both lose information and add false information at the same time. Maybe you can make the noise removal only at the last stage of your processing workflow and display two versions.
Are you referring to the smallscale 'features" on the left side? Perhaps because I dealt with them all the way through, I never really thought of them as looking like real features. Perhaps this is why when I was debating this with Stefan, he kept mentioning the features on the lower left side of the image and my reply was always to the effect of "what features on the left side of the image?"
Yes I am, I have no problem with the features that you have identified.
This is an alternate take in which I tried to wipe that out, but it never looked quite right.
Here is my Borrelly image at its original size. The other version was made to enlarge well for a size comparison Emily was doing. Both original frames for this image are smeared, which also creates some effects. This is the image at 133% of its original size. The left hand side is raw, the right hand side is my version before I worked to make it bigger for the comparison image. The right hand image has a partial overlay from the next closest image to reduce noise.
Hi,
Just my small contribution to this topic. Here's a quick processing of the Proteus image. I was completelly conservative on appliying gausian blur filters to reduce noise and levels adjustment. There's some cliping of the darkest parts of the image in an atempt to reduce uncertain details at high noise levels.
The general details visible on Ted's images are present, and a hint of the finer ones.
I think that the issue here is the balance between further processing and the introduction of processing artifacts. It's a complicated decision and is related to image scale and sampling.
I think it's fascinating to see a comparison of the results of different people's efforts to process a single image, especially one of such marginal quality but such great significance as this one shot of Proteus (honestly, when does anybody think we'll get another chance to look at Proteus?) You each have a slightly different approach and a range of goals, as well as a range of willingnesses to accept the possible introduction of artifacts in order to generate a pleasing product. Yet all the approaches appear to be systematic (in that they should be reproducible -- no actual subjective painting, for instance). Anybody else want to try?
--Emily
Emily,
I'll give it a shot !! (and thanks for throwing down the velvet gauntlet)
(designing non-linear programs for noise reduction and focus is my preferred way to relax!)
Ted <wizard!> where would a humble programmer obtain the calibrated source images of Proteus?
stay tuned
In the spirit of teaching a man to fish...
http://old-pds-rings.seti.org/catalog/vgriss.html
Select "PROTEUS" from the dropdown menu in the Neptune targets line, and I recommend you select "detailed" from the "Listing type" dropdown menu under the Query Results header at the bottom of the page, and also ask to see preview gifs. I get 42 records returned; you'll need to go back to the query form and tell it to skip the first 32 records to see the image you're after. (Alternatively, here's http://old-pds-rings.seti.org/volumes/VG_0011/1989N1/C1138920.IMQ, which you can convert from PDS format using IMG2PNG or NASAView.)
These data are pretty raw. The rings node is working on developing calibrated and geometrically corrected Voyager data sets, but to date they have only done so for Uranus and Saturn, and even those data sets aren't quite through peer review yet.
--Emily
Here is my calibrated base. Keep in mind that in this version, the sections of the Proteus frame that were not transmitted look awkward due to the fact that they were filled in with pure black on the PDS raw image.
Here is another image that is shown in a very odd form, the HST Venus image. First of all, it is given a garish false color. Second, its contrast is stretched beyond reason, creating a false crescent.
If this suggestion involves much work, my apologies, but if it is just some click and drags (and no one has tried this yet) go for it;
would it help to verify an image processing technique to try it on, for instance, a Voyager Encedalus image, and then compare the enhancement to a subsequent Cassini image of the same area ??
If a particular technique makes particular details stand out in a Voyager image that are verified in a Cassini image, then perhaps if the same were done to, for example, a Voyager Uranus Puck image, then we might have some expectation the technique is worthwhile.
I might then suggest using the technique on some Cassini images . . .
(heh, heh)
The data issues with those are totally different. tasp, I find your snide "if it involves too much work" comment interesting....why don't you do it if it is so easy? There isn't a dataset out there (to my knowledge) like the Proteus image. So sharp, so close, and yet so underexposed. The fact that the major features all corresponded to the other images is good enough for me. I realize that noise is still a factor, but my position versus Tayfun Oner's is basically one of being willing to leave salt and peppering noise to cue a viewer that the picture is noisy or create a clean looking product that might lead an uninformed viewer to mistake noise for a real feature. When I am trying to make pretty pictures, the later is my choice. I would be much more careful if I was working on an image for scientific purposes, such as on my work with Ariel.
I have no way of knowing how much effort is involved in processing an image once a technique is developed. I have (don't laugh) HP image Zone on my PC and you just select a picture and click various settings on it and view the result. I am sure all of you are doing things much more advanced than that, and I have absolutely no idea how much effort is involved in restoring a particular picture once you have written some software to do it, nor could I have any idea unless specifically informed about a specific process.
I did not want to have anyone go to a lot of effort on one of my suggestions, but if it is easy to do, like I said, go for it. Don't anyone put themselves out on my account. I would never request someone put hours into trying out something I came up with, but if it s just a few seconds operation involving a click and drag, why not give it a try ?
Was not trying to be snide (just skirting topic of how dumb I am in regards to how computer image processing works) so apologies if that is how it came across.
Well....it has been about 2 weeks...two weddings, one funeral, one tropical storm, and the start of school again...but I did promise I would take a swing at the Proteus image.
First, my congrats go to Ted and the NASA people who have tried to work with this image. There are only a half dozen or so of actual DNs in the image. I took each DN level and processed it and then merged them. The eastern limb is a WAG ( wild a** guess) but there are faint impressions of a crater in the northwest and an elongated crater, centered in the due west bright area.
Warning: for obvious reasons, this is a highly processed image.....your mileage may vary...
(thanks to Emily for teaching an old angler to fish, and Ted for someone to aspire too!)
One thing that I wanted to emphasize. The thing that bothers me about the NASA version is that it is a quick-n-dirty from right after the encounter. There are better versions from the science teams of this and a lot of these images.
I decided to take a look at the Proteus image as well. My goal when processing these is aesthetic in nature: create an image that looks like a moon, not a flat bumpy rectangular thing. The main difference between this image and better images is in the frequency histogram, aka the Fourier Transform. Correct that, and the image looks a lot more real. Therefore, the main operation I used was a low-pass filter to enhance the feeling of sphericalness and decrease noise, all while keeping enough small-scale details. Below is an animated gif showing three steps: a stretched, dereseaued, and deposterized (is that a word?) version of Ted's calibrated base, a sharpened and medium-pass enhanced version of the base, and the final product.
Hi all,
I wrote a small program in Actionscript 3 (Flash) that performs linear interpolation to 8 bits on images with low bit levels originally. It's very basic and only works in one axis, but i can get around that simply rotating the original image 90º and averaging the results with the non rotated interpolation.
I tried it on the Voyager 2 Proteus image discussed in earlier posts. I must say I like the results.
The raw image was histogram stretched and cleaned of noise before interpolation. The interpolated image was then processed in Photoshop.
What I got is the image bellow.
Any ideas regarding other good images to test the program, besides the Viking sunset/sunrise images that I've already thought about?
That looks like a good result, but could you explain your use of "interpolated." Usually it is used to remove missing lines and pixels, but I am assuming this is used to reduce the "stair-stepping" effect. Am I correct?
"I am assuming this is used to reduce the "stair-stepping" effect."
Yes, that's it. I'll try to explain better:
Let's imagine that he have an image with pixel values, along a row, something like this:
100 110 110 110 120 120 110 100
What the program does is reading each pixel value and counting for how many pixels is that value the same as the previous pixel.
It's just like saying, in common language: there are 3 pixels in a row with a value of 110, and then the next pixel's value is 120.
Then the program divides the total pixel value difference (in this example 120-110=10 levels) by the amount of pixel the value stayed the same (3 pixels).
These 3 pixels with the same value are then replaced by a gradient (110 113 116).
So the resulting image data would be something like:
100 110 113 116 120 120 110 100
Hope this makes things a little clearer. I've tried it on the viking images, and it does give a smooth sky, but noise creates artifacts. So i need more time to optimize the code and try to ignore level changes due to isolated pixels.
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.
Ted -- is it true that Endeavour Crater is resolved in these mosaics?
-the other Doug
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.
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.
Yes, the trio of craters, with Endeavour at the north end, is clearly visible.
Here's another historic image:
Yes, it does, especially in color. The image on the left is a true tri-color, the image on the right is only colorized.
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?
http://www.vk3ukf.com/Mars/Mariner/Mariner4Redone_page_01.htm
What did you use as your data source?
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/mariner_4_image_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/Mariner4Redone_page_01.htm
I think they come from http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m04_01d.html
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?
Picture #1
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?
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.
Very cool!
I've been fooling around with some really convoluted stuff lately. Here is an image of Comet Tempel-1 I have been working on.
Fantastic, as usual, Ted. The Tempel 1 departure view leads me to wonder, do the earliest approach views look any different from the closeup images? Any visible rotation?
Phil
(PS I'm looking at Icarus...)
I would have to look more carefully...I am tempted to say yes, but it is easy to be fooled by spacecraft motion.
He'll be far too modest to plug it himself, so I'll point you all towards Ted's relaunched blog... http://planetimages.blogspot.com where you will find some truly stunning images. The "new views" of Ganymede are breathtaking - it's like watching images come in from a probe sent to an alien solar system, and seeing one of its worlds for the first time.
Go. Look. And shake your heads in wonder...
I have added some updated versions of Galileo's global crescent views from 1997.
http://planetimages.blogspot.com/2009/09/despite-its-antenna-problems-galileo.html
Hello
I send some mosaics from Mariner 9. And so it is uploading test .
Nice Mariner 9 images, really smooth. Good work.
Nice work!
Thanks!
Now for something completely different from Mariner 9.
Machi very excellent work
I send one original image from Mariner 9 (mosaic is from three images), so you can compare original and result.
Images are improved so, that I'm trying preserve original usefull information and remove noise and reseau marks. Especially in widefield Mariner 9 images is problem with horizontal errors. Color is entirely artificial, just for better look.
What is your source for the raw data? The one above looks much better than any scan of a print I've seen.
My personal archive is converted from http://pds-imaging.jpl.nasa.gov/Admin/resources/cd_m71.html#m71EDR by img2png (thanks to Bjorn Jonsson and PDS!) to png.
I didn't realize that the data that old was available electronically. Good work. I wish I had the time to try some of that.
I think that these images are oldest electronically available on internet.
I remember that mosaic well! I think it was on the cover of New Scientist at the time. It was the first ever full-disk (almost) image of another planet which showed dramatically more detail than a telescopic view, so it made a big impression on my 15-year-old self- it made Mars suddenly seem very real. It never looked this good back then though- nice restoration job!
John
"I think that these images are oldest electronically available on internet."
No, the digital Mariner 6 and 7 images are available here:
http://ser.sese.asu.edu/M67/mar67.html
Phil
Fantastic! Thank you very much. I didn't know about this.
The Mariner 6-7 images on that site have a few issues, but they are pretty good. If I ever actually have time to work on an image again, I need to finish my Mariner 6 and 7 set. Here is my recent blog post related to this http://planetimages.blogspot.com/2009/09/meridiani-in-1969.html
Excellent work!
Thanks!
Especially in this case, I have strong inspiration from your images. Your works based on Voyager 2 images are amazing!
6N03
Peter, I strongly agree.
That first image is great - one of the best images of Mars' limb that I have seen.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)