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Nightlights
http://forum.celestialmatters.org/viewtopic.php?f=6&t=222
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Author:  cartrite [ Wed, 14-05-08, 11:19 GMT ]
Post subject:  Nightlights

I did 3 different nightlight textures.
This first one is using Radiance Calibrated Lights: 1996-1997 from http://www.ngdc.noaa.gov/dmsp/download_ ... 96-97.html

Image

Full resolution
http://img111.imageshack.us/img111/6295 ... ay1mk3.jpg

This second one is using Stable Lights from http://www.ngdc.noaa.gov/dmsp/download_ ... 94-95.html

Image

Full resolution
http://img111.imageshack.us/img111/4737 ... ay2be0.jpg

This third one is using Radiance Calibrated Lights: 1996-1997 again but I set the contrast to -50 and set sharpen to 50 with the Gimp.

Image

Full resolution
http://img111.imageshack.us/img111/1240 ... ay3qm0.jpg

I think it is a toss up between 1 and 3.
cartrite

Author:  t00fri [ Wed, 14-05-08, 17:02 GMT ]
Post subject: 

A long time ago I made my 32k Nighttime light VTs from the radiance calibrated raw texture with the help of my F-TexTools. It's very easy. The stable lights look pretty horrible.

Another enhancement is to colorate the texture with a true-color reference image taken by astronauts ...
e.g.
http://spaceflight.nasa.gov/gallery/ima ... 2-0014.jpg
but there are many in the net.

Fridger

Author:  BobHegwood [ Wed, 14-05-08, 21:28 GMT ]
Post subject: 

Haven't gotten around to the Radiance Calibrated Lights yet, but I appreciate what you have left for me to play with here. :wink:

I have completed my operations on the Stable Package, and the following are two samples:

Image

and

Image

I had to increase the gamma by a factor of 2.22 and then sharpen each of the tiles. Did this by hand for EVERY tile, so now you really know how smart I am. :roll:

Looks a lot better though. Will get to the other packages as I can get the time here.

As always, Steve, your help is MUCH appreciated. :D

EDIT: Note that the Italy night lights image above has been improved immensely now. Compare this image with the lower image of Spain, and you will see how I have further improved my night textures using a batch process from the IrfanView program. See my post HERE for more information.

Author:  cartrite [ Wed, 14-05-08, 22:24 GMT ]
Post subject: 

t00fri wrote:
A long time ago I made my 32k Nighttime light VTs from the radiance calibrated raw texture with the help of my F-TexTools. It's very easy. The stable lights look pretty horrible.

Another enhancement is to colorate the texture with a true-color reference image taken by astronauts ...
e.g.
http://spaceflight.nasa.gov/gallery/ima ... 2-0014.jpg
but there are many in the net.

Fridger
I like this idea. As soon as I free up some space on my main SATA disk, I'm going to put some more effort into this.

Bob wrote:
Will get to the other packages as I can get the time here.
I think the Radiance Calibrated Lights are worth the effort. But as Fridger says, some real color satellite images are needed to tune it in. By setting the contrast lower, it gets to looking more like the Stable Lights. But I'll have to look at some astronaut images to see which one is closer to what it really looks like.

My first impression of the Stable Lights are they are overkill. But the Radiance Calibrated Lights seem under exposed.
PS We were getting a bit off topic with the night lights which is why I started this thread.
Bob, your images look pretty good. Europe looks better than the US which is what I looked at with the texture I did.
cartrite

Author:  Andrea [ Wed, 14-05-08, 23:30 GMT ]
Post subject: 

In the link given by cartrite (thank you very much!) here
http://www.ngdc.noaa.gov/dmsp/download_rad_cal_96-97.html
I found this page, Version 2 DMSP-OLS Nighttime Lights Time Series
http://www.ngdc.noaa.gov/dmsp/global_composites_v2.html
where I downloaded the F152003 file, then reduced it to a 16k png file, and this is the result, for the same area shown by Bob:

Image

I think this is more real and less “patchyâ€

Author:  cartrite [ Wed, 14-05-08, 23:57 GMT ]
Post subject: 

I also tried the Version 2 DMSP-OLS Nighttime Lights Time Series and downloaded the same F152003 file. Problem with that file is that it only covers from 65 north to 65 south latitude. So that requires extra work. It is the closest data to the bmng data from 2004 though.
cartrite

Author:  BobHegwood [ Thu, 15-05-08, 0:10 GMT ]
Post subject: 

[quote="Andrea"]In the link given by cartrite (thank you very much!) here
http://www.ngdc.noaa.gov/dmsp/download_rad_cal_96-97.html
I found this page, Version 2 DMSP-OLS Nighttime Lights Time Series
http://www.ngdc.noaa.gov/dmsp/global_composites_v2.html
where I downloaded the F152003 file, then reduced it to a 16k png file, and this is the result, for the same area shown by Bob:

I think this is more real and less “patchyâ€

Author:  t00fri [ Thu, 15-05-08, 0:21 GMT ]
Post subject: 

I quickly colorated Andrea's 16K nighttime image with GIMP, using his zoomed-in color image of Rome at night.

Image

It's a most useful feature of GIMP!

Fridger

Author:  Andrea [ Thu, 15-05-08, 0:25 GMT ]
Post subject: 

BobHegwood wrote:
Ooh... That's pretty...
I like this much better than my hard-won version. Will attempt to see if I can recreate your images on my system here.
Thanks VERY much Andrea. :D

You are welcome,Bob.
I'm using your scripts from a while, even if I have widely modified them, but this is on top of them (this is for the Earth Tour):

{
#------------------------------------------------------------------------
# EarthTour.cel 4.0: Touring Earth- Italian release by Andrea Pelloni.
# Original script V1.01 by Bob Hegwood on 20 Jul 2004.
# Modified by Andrea Pelloni starting from August 2005
# Images sequences are from "Deep Impact" movie trailers, and from NASA public releases.
# Dinosaur images have been heavily modified and redrawn from sketches.
#------------------------------------------------------------------------


So I have to thank you, not vice-versa. :wink:
Bye

Andrea :D

Author:  Andrea [ Thu, 15-05-08, 0:31 GMT ]
Post subject: 

t00fri wrote:
I quickly colorated Andrea's 16K nighttime image with GIMP, using his zoomed-in color image of Rome at night.
It's a most useful feature of GIMP!
Fridger

Fridger, it's very nice and realistic, I love it.
Tomorrow I'm going to produce a 32kVT using your F-textools, but I'll previously colorize it as you did, with Gimp. :wink:
Thank you very much.
Bye

Andrea :D

Author:  cartrite [ Thu, 15-05-08, 4:11 GMT ]
Post subject: 

Here is a colorized unaltered Radiance Calibrated Lights

Image

Here is a colorized Radiance Calibrated Lights that had contrast set to -50 and sharpen set to +50.

Image

cartrite

Author:  Andrea [ Thu, 15-05-08, 9:39 GMT ]
Post subject: 

Cartrite, this is my 16k nightmap as seen in celestia 1.5.1, colorized as suggested by Fridger and saved as .dds DXT1c:

Image

Searching for a real comparison, I found this very interesting page
http://earthobservatory.nasa.gov/Study/CitiesAtNight/
where, more than the still images, the most interesting thing is the movie you can find at half page,
“world tourâ€

Author:  cartrite [ Thu, 15-05-08, 9:53 GMT ]
Post subject: 

Thanks Andrea,
I'll give a look to the movie. From my experience though, I notice that sodium lamps tend to be around cities, interstate highways, etc. and rural areas tend to have the older white light lamps. There is no doubt there are a few different light sources depending on which country your looking at and what the population density is.
Question. Which Gimp tool are you using? I used the channel mixer which is a quick uncomplicated way of doing a simple colorization.
cartrite

Author:  Andrea [ Thu, 15-05-08, 10:07 GMT ]
Post subject: 

cartrite wrote:
Thanks Andrea,
I'll give a look to the movie. From my experience though, I notice that sodium lamps tend to be around cities, interstate highways, etc. and rural areas tend to have the older white light lamps. There is no doubt there are a few different light sources depending on which country your looking at and what the population density is.

Yes, I agree, and this makes a solution almost impossible, needing a manual reworking of everything, that's absurd, obviously.

cartrite wrote:
Question. Which Gimp tool are you using? I used the channel mixer which is a quick uncomplicated way of doing a simple colorization. cartrite

Before trying The Gimp, that I never used before, I tried with my old Photoshop CS3, using the very simple "Image" > "Adjustments" > "Variations", as shown here:

Image

Just a minute, no more. :wink:
By

Andrea :D

Author:  cartrite [ Thu, 15-05-08, 10:27 GMT ]
Post subject: 

After watching the hires movie, I agree. An almost impossible task. Photoshop CS3 looks interesting. The method I used was quick and easy but not at all accurate. The full VT's is small though as far as disk storage. All the VT folders are only about 7 mb for the grayscale and 30 mb for the colorized versions so I can play around with these.

I used your image of Italy and used the channel mixer to get close to your image of Rome. Then I saved the settings to a file and colorized the Radiance Calibrated Lights with the channel mixer using the settings file I saved previously.
cartrite

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