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 Post subject: Image enhancing
PostPosted: January 1st, 2023, 14:33 
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Not strictly data recovery but ...

We all laugh when Hollywood enhances a blurry image to reveal number plates and facial features, but what about this?

https://www.apolloremastered.com/the-image-processing

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 Post subject: Re: Image enhancing
PostPosted: January 1st, 2023, 18:07 
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Beautiful!! But this type of enhancement is working with data that is actually available, where Hollywood wants us to believe you can pull data from thin air. A 3 pixel number plate will never get you read-able plate imho. While stacking individual frames from a video might work to clean up an image. But again that's optimizing data that is actually available. I did some astrophotography myself and image stacking then is standard procedure, there's tools that are created for that purpose only.

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 Post subject: Re: Image enhancing
PostPosted: January 2nd, 2023, 18:00 
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i was thinking about this a few weeks ago with my son. If you have a single underexposed image, a significant amount of information is missing, the image has a lot less brightness levels, which will result in the same amount of discrete levels after amplifying it. One can try to add that info manually but i would not call this image processing, it resembles more to some kind of an art. It looks good at the end and might be close to the original subject, but it is still an artificial image.
I agree that it is a lot different if you have multiple images, from which it is possible to get more info and restore a better single image.

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 6:11 
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Very nice indeed. It never occured to me that noise in a stack of images is random. Very powerful.

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 9:51 
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pepe wrote:
i was thinking about this a few weeks ago with my son. If you have a single underexposed image, a significant amount of information is missing, the image has a lot less brightness levels, which will result in the same amount of discrete levels after amplifying it. One can try to add that info manually but i would not call this image processing, it resembles more to some kind of an art. It looks good at the end and might be close to the original subject, but it is still an artificial image.
I agree that it is a lot different if you have multiple images, from which it is possible to get more info and restore a better single image.


Well, I'd say the info is actually inside the file. It has nothing to do with adding data or say 'fabricating' things. These kind of misunderstandings are the seed of all kinds of conspiracy theories.

These are scans that are publicly available. So I just took one sort of randomly that looks underexposed, and downloaded the TIFF file just like the author of the book did,
http://tothemoon.ser.asu.edu/gallery/Ap ... 11-36-5292

Attachment:
hasselblad_under.jpg
hasselblad_under.jpg [ 108.32 KiB | Viewed 12815 times ]


By just slightly adjusting levels of the huge TIFF file we bring out details that were initially invisible. Purely image processing. I did not 'add' anything, I simply exposed what was invisible in original scan. This is one of the techniques used by the author of the book, he's just better at it and put more time into it than me. This enhancement took me 3 seconds of my time and a free photo editor.

Attachment:
hasselblad_lvls.jpg
hasselblad_lvls.jpg [ 177.97 KiB | Viewed 12815 times ]

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 17:46 
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you will have exactly same amount of discrete brightness levels after adjusting it. That said, the info that was between these levels is lost. it is just not there.
Say it has levels 0-10 on one channel, you adjust it to be 0-100, but you will get 0,10,20,30...90,100.
you won't get 15,33,78 or anything in between.
so those details are lost. we can artificially smooth out this quantization so the image can have smoother transitions between these levels, you will have the feeling it is ok, but if there was some detail with levels other than 10,20,30...100 these will not be there in your smoothed image.
It will look good though

pepe

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 18:10 
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Found original TIFF scan of the astronaut: http://tothemoon.ser.asu.edu/gallery/Ap ... 09-24-3665

A far cry from the result of the author of the book, but just to show:

* data is there. Of course over/under exposure washes out data, it's working with the little data you have. But author of that book didn't pull the data out of his arse.
* a few minutes of tinkering is all required to reveal some of the data

Yes, sure, some artistic liberty was taken by author to create a visually more pleasing picture, even the crop is an 'artistic choice'. But "it's just not there" seems an incorrect statement. Keep in mind that this type of photo processing isn't my expertise, I fix structural issues mainly. I'm just tinkering and I'd argue working with what's already inside the data, however little this is. And I'd argue most of what you see in the enhanced photo here, https://www.apolloremastered.com/the-image-processing, was already inside the data.

https://youtu.be/Tq9vYzgb4iU

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 19:58 
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the 'just isn't there' was not about what you or anybody can reveal by adjusting the levels. I meant that there is no detail in between those levels. I never meant to say there is no data at all if we can't see it because of being underexposed, just that a lot of the details are lost because the very low number of levels actually showing up in the image.

btw, the before-after pic is also a cheat because the image downloaded from your first link already shows something while his 'before' pic shows full black except the window. So we are definitely talking about different things, i took his 'before' pic as a basis of my comments.
I, as anybody else, was able to make the pic you linked a lot more enjoyable in 5 minutes of adjusting but i'm afraid his 'before' pic was darkened intentionally
Attachment:
apollo.png
apollo.png [ 61.38 KiB | Viewed 12757 times ]

this is what you get if you start adjusting the levels of his 'before', with its histogram. Fairly obvious that pic contains very few levels, a lot fewer than what you linked as originals...
So where is the big deal? presenting a manually degraded image as original while using another one as a basis of our transformation????

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 20:50 
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pepe wrote:
the 'just isn't there' was not about what you or anybody can reveal by adjusting the levels. I meant that there is no detail in between those levels. I never meant to say there is no data at all if we can't see it because of being underexposed, just that a lot of the details are lost because the very low number of levels actually showing up in the image.

btw, the before-after pic is also a cheat because the image downloaded from your first link already shows something while his 'before' pic shows full black except the window. So we are definitely talking about different things, i took his 'before' pic as a basis of my comments.
I, as anybody else, was able to make the pic you linked a lot more enjoyable in 5 minutes of adjusting but i'm afraid his 'before' pic was darkened intentionally
Attachment:
The attachment apollo.png is no longer available

this is what you get if you start adjusting the levels of his 'before', with its histogram. Fairly obvious that pic contains very few levels, a lot fewer than what you linked as originals...
So where is the big deal? presenting a manually degraded image as original while using another one as a basis of our transformation????


Start of discussion is photo enhancement "Hollywood style". All I am saying this enhancement in Apollo photos isn't Hollywood style. Hollywood style assumes we can pull data from thin air and enhance a 3 pixel number plate into something readable. It is about information that is actually there, Apollo edits illustrate that.

I am using 2 images, the originals, the TIFF scans and play with levels. I claimed nothing else than that and that's what I did.

This is original used in video, not an artificially degraded image: http://tothemoon.ser.asu.edu/gallery/Ap ... 09-24-3665

What's you're using is an already processed image, probably some lower res JPEG for web use = missing the point spectacularly. How would the page load when he'd use the almost 1.3 GB original scan?

You can take levels of this but it will not tell you anything that can be 'recovered' from original because it's edited for web use. Just like the before - after examples. I fail to see what your histogram is supposed to illustrate, it's a darned tiny pic for website use. Anyway, this is a JPEG made with information I took from the underexposed TIFF scan, it has nothing to do with art, the information is there.

Attachment:
AS09-24-3665s.jpg
AS09-24-3665s.jpg [ 852.88 KiB | Viewed 12748 times ]
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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 21:45 
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I recall another thread in another forum where are user was only able to recover thumbnails of his lost photos. I wonder whether it would be possible to enhance these photos using AI. I see lots of promising examples here:

https://www.google.com/search?q=%22image+enhancement%22+%22low+resolution%22

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 21:58 
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Quote:
What's you're using is an already processed image, probably some lower res JPEG for web use = missing the point spectacularly. How would the page load when he'd use the almost 1.3 GB original scan?


it is not about the resolution, what he showed on the left is not the original image and not in the sense of resolution (who cares about resolution?) but in darkening it significantly, and marking the darkened image as original. This is where i feel cheated.

this is what i made quickly out of the original you linked:
Attachment:
apollo2.jpg
apollo2.jpg [ 106.34 KiB | Viewed 12738 times ]


but the previous one i made from his 'before' pic which was definitely darkened significantly, not the original in the sense of lighting, not talking about resolution which is not really important right now.

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 Post subject: Re: Image enhancing
PostPosted: January 3rd, 2023, 22:16 
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Quote:
it is not about the resolution, what he showed on the left is not the original image and not in the sense of resolution (who cares about resolution?) but in darkening it significantly, and marking the darkened image as original. This is where i feel cheated.


low res, low quality.

Quote:
this is what i made quickly out of the original you linked:
Attachment:
apollo2.jpg


but the previous one i made from his 'before' pic which was definitely darkened significantly, not the original in the sense of lighting, not talking about resolution which is not really important right


It looks awesome! how do you balance the brighter <> darker parts if I may ask? Again, I'm a noob when it comes to these kind of edits.

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 Post subject: Re: Image enhancing
PostPosted: January 4th, 2023, 10:05 
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i am noob as well when it comes to photo editing, just used mask. I am pretty sure it can be done a lot better by applying some lighting and colouring, but i am not a master of this thing, only have the ideas but not the experience how to do it right.

Quote:
low res, low quality.

true but currently our problem is not the x-y resolution but the very low dynamic range of colors. And his 'before' image has a lot less levels present than the original we used, there's where i suspect cheating...
btw, for the above pic i used the small (800kb) version. Of course, if you have a large TIFF with lossless compression, there will be far less noise in the result as well. But for demonstration the smallest one is perfectly ok.

pepe

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 Post subject: Re: Image enhancing
PostPosted: January 4th, 2023, 10:45 
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pepe wrote:
i am noob as well when it comes to photo editing, just used mask. I am pretty sure it can be done a lot better by applying some lighting and colouring, but i am not a master of this thing, only have the ideas but not the experience how to do it right.

Quote:
low res, low quality.

true but currently our problem is not the x-y resolution but the very low dynamic range of colors. And his 'before' image has a lot less levels present than the original we used, there's where i suspect cheating...
btw, for the above pic i used the small (800kb) version. Of course, if you have a large TIFF with lossless compression, there will be far less noise in the result as well. But for demonstration the smallest one is perfectly ok.

pepe


Ah, well okay.

Well my original point is, image enhancement can only work with data that actually exists. So, underexposed giant TIFF of 1.2 GB is bound to give information to work with, a 3 pixel number plate does not. This is what I mean, although Hollywood wants us to believe that somehow 3 pixels contains enough information to be enhanced into a readable number-plate.

The 1.2 GB TIFF has enough 'body' to work with, make information visible without the need to be artistic.

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 Post subject: Re: Image enhancing
PostPosted: January 4th, 2023, 11:38 
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i doubt you could gain a significant amount of valuable information from a similarly underexposed image by boosting the x-y resolution. It will contain more pixels but not more levels...

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 Post subject: Re: Image enhancing
PostPosted: January 4th, 2023, 17:12 
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Oh F.F.S.!

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