It's a bird

by Vian Esterhuizen

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293 reputation
211
bio website john.jersdesk.com
location North Salt Lake, UT
age 43
visits member for 4 years, 7 months
seen Jun 24 at 15:21

I am a software developer. I am particularly fond of the areas:

  • artificial intelligence, computer vision & machine learning
  • high end graphics & image processing
  • games

As this profile is now posted across multiple sites:

I am a member of the Church of Jesus Christ of Latter-Day Saints, also known as a Mormon.
I am also a mathematician.
I quite like interesting games and enjoy playing them with those of my many wonderful children who are old enough. We will often edit what we might find to be sleazy in a game without altering the game play, which quite widens the range of games we can play while staying within what we consider to be gospel standards.


Jun
23
comment Is there a trick to separate an old photo moisture-fused to glass?
The glass had cracked on one photo, and we recovered quite a bit more near the crack and photo edges. We also went way, way past 20 minutes allowing the edges to fray, as the center was more important. Cracking the glass intentionally poses obvious risks. But I kind of wonder if breaking the glass more before soaking might have actually worked better. Maybe, maybe not, and no way to know offhand.
Jun
23
comment Is there a trick to separate an old photo moisture-fused to glass?
I think it was our best hope and very clever, but we still had a lot that wouldn't separate from the glass.
Jun
22
asked How is depth of field usually measured and how can I get depth of field measurements for a lens
May
10
awarded  Notable Question
Mar
7
revised How can I automatically correct aerial perspective in landscape photographs?
added 187 characters in body
Mar
7
revised How can I automatically correct aerial perspective in landscape photographs?
added 659 characters in body
Mar
7
answered How can I automatically correct aerial perspective in landscape photographs?
Mar
7
comment How can I automatically correct aerial perspective in landscape photographs?
Oh cool, and I just realized I can get a cheap wavelength specific version if I can find a source for average color spectrum of daytime sky (and then apply the trick in my previous comment)
Mar
6
comment How can I automatically correct aerial perspective in landscape photographs?
I'm sure this has been studied and a "per wavelength" results for distance D have been derived or extracted. Typing these out it occurs to me that a cheap version is to ask how much air is standing in a column above you to add up to 1 atm air pressure at sea level. Then assume the effect is linear and that aerial perspective is linear in the amount of air standing between you and your subject and use an average sky value for averaging. I'll have to try it out.
Mar
6
comment How can I automatically correct aerial perspective in landscape photographs?
@DrMoishePippik Clever idea, but there is relatively little of that and actually overexplosed points can still show as true white (because as long as "enough" light gets through to push a pixel to white it will still show as white)
Mar
6
comment How can I automatically correct aerial perspective in landscape photographs?
@Rafael You are correct. It is just as complex as sky color (because that is actually how the sky gets its color). But for such things usually autocorrecting to an "average expectation" is far better than doing nothing.
Mar
6
comment How can I automatically correct aerial perspective in landscape photographs?
@mattdm Aerial perspective and linear perspective both show distance. Geometric perspective shows it by distortion, aerial shows it by color change (mountains in the distance are blue and hazy, i.e. a change in color shows distance)
Mar
6
asked How can I automatically correct aerial perspective in landscape photographs?
Dec
4
accepted How does the usual jpeg 0-100 quality settings translate into Photoshop's 0-12 quality setting?
Dec
4
awarded  Curious
Dec
3
comment How does the usual jpeg 0-100 quality settings translate into Photoshop's 0-12 quality setting?
I did see that one. I didn't think it did. But possibly it is the case that quality number 0-100 isn't actually part of the jpeg standard (i.e. there aren't quantization tables specified in the standard by a given quality number) and so there IS no direct translation between adobes and libjpegs quality numbers because they actually use different quantization tables altogether. If that is the case, then there really isn't a translation between them and the answer you pointed to is as good as it is going to get.
Dec
3
asked How does the usual jpeg 0-100 quality settings translate into Photoshop's 0-12 quality setting?
Dec
3
accepted Is light fall off corrected for in modern cameras?
Nov
16
revised Is light fall off corrected for in modern cameras?
deleted 24 characters in body
Nov
15
comment Is light fall off corrected for in modern cameras?
@MichaelClark. No, in this case it is that simple. It has nothing to do with the actual choice of lenses used to make the projection. It is purely a property of the projection from outside world to photographic film or sensor. Ultimately no matter how many lenses you use they are put together to make a linear projection, and it is a property of that alone.