Advice on enhancing digital image

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Discussion Overview

The discussion revolves around techniques for digitally enhancing a sequence of images taken from a distance, specifically focusing on distant buildings and the challenges of visibility due to atmospheric conditions. Participants share software recommendations, personal experiences, and observations related to image stacking and enhancement methods.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests using Photoshop to overlay images with 'multiply' or 'difference' blending modes for enhancement.
  • Another participant recommends using RegiStax for stacking images before editing in Photoshop.
  • A participant shares their experience of seeing distant buildings and speculates about the visibility of Niagara Falls due to a superior mirage effect.
  • Discussion includes calculations regarding horizon visibility based on height and distance, with one participant providing a link to a horizon calculator.
  • Some participants express skepticism about the visibility claims, noting personal observations that contradict the calculations presented.
  • Multiple software options for image enhancement are shared, including Neat Image and other noise reduction tools.
  • A participant discusses challenges faced when trying to align images for stacking, particularly with camera rotation affecting timestamps.
  • There is mention of a Microsoft project called Photosynth that creates a virtual world from photos, which some find impressive while others are less enthusiastic.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding visibility claims and the effectiveness of different software tools. There is no consensus on the visibility of distant objects or the best methods for image enhancement.

Contextual Notes

Participants' claims about visibility are dependent on various assumptions, including atmospheric conditions and height above sea level. The effectiveness of suggested software tools may vary based on individual experience and specific use cases.

Who May Find This Useful

This discussion may be useful for photography enthusiasts, particularly those interested in digital image enhancement techniques and the effects of atmospheric conditions on visibility.

DaveC426913
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I've got a sequence of pictures from my camera of some very distant buildings (~20mi) that I'd like to digitally enhance. I took about 20 shots in rapid succession in the hopes that I can combine them to produce a better image.

My first attempt will simply be to overlay them in PhotoShop and use the 'multiply' or 'difference' blend.

I'd like some advice on how to easily enhance these. (This is just for fun. I don't mind downloading some s/w package, but I'm not going to go to great lengths.)
 
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Thank You! Cool program! Here's my results:

Whenever I come over the Islington bridge into New Toronto I get a gorgeous view of Lake Ontario. On a clear day, I can see the water tower in Niagara-on-the-Lake, but I've never seen this far before.

Today I could see tall clustered buildings. Could it be? Could I be seeing 40 miles all the way to Niagara Falls?

Probably, but I never miss an opportunity for geekiness.


So I snapped off about twenty identical shots:
0000t8f5.jpg


You can just barely see the horizon lost in the haze.

Then I ran them through RegiStax. (cool program!)

And then I checked GoogleEarth and plotted the line of sight from Toronto, rotating the satellite image appropriately.

Then I looked for likely candidates - the Skylon Tower being the most obvious (the leftmost - looks like the CN tower). Long shadows are easier to spot than actual buildings.

And lookie!

0000wasa.jpg


P.S. The reason Niagara Falls was visible today is not because the air was particularly clear, it is because of the Mirage Effect - specifically a superior Mirage. Niagara Falls, being 40 miles away is over the curve of the Earth, but the air over the water bends the light over the curve, creating an image above that of the position of the actual object, thus:
mirtowr.gif
 
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This may be of interest. It'll tell you just how far your horizon is and how high objects have to be to be visible (normally): http://www.boatsafe.com/tools/horizon.htm

Near as I can tell, the observation deck is about 450 feet up and the base is 250 feet above the lake, which puts its horizon at 35 miles. Judging from your picture, you are a good 40 feet up, which puts your horizon at 8.5 miles. So I think you should be able to see it on any decent day.
 
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What did one or two of your originals look like?
 
russ_watters said:
So I think you should be able to see it on any decent day.
Huh. That makes sense but it's not true in reality - and I look all the time. (I always spot the water tower in good days.)



I don't know how high above the water I am, though it shouldn't be hard to figure it out. I'm only 1/4 mile from the lake but I'll have to check on the height of the bridge.

robphy said:
What did one or two of your originals look like?
That was one of the images I attached in my post.
 
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My backyard. I coudlnt figure out how to use that program to put them together though..

Redid a better picture.

http://img232.imageshack.us/img232/7241/housesv4.jpg


I had the camera on a roll of paper towels and turned it, so it was always level. You can see when I put the pictures together how the time stamp drifted. Turns out that every time you rotate the camera, you need to tilt it for the pictures to match.
 
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Although my post is a little off-topic, cyrusabdollahi's composite photo reminded me
of this new Microsoft project: http://labs.live.com/photosynth/,
which creates a virtual world from a collection of photos that it somehow
stitches together in 3D. It's rather impressive. (The "Tech Preview" is an ActiveX plugin.)

Here's an image from someone's flickr contribution:
407622006_2bf27b5911.jpg
 
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  • #10
robphy said:
It's rather impressive.
Sure. If I were impressed by watching my computer puke.
 
  • #11
DaveC426913 said:
Sure. If I were impressed by watching my computer puke.

Worked for me.
 

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