removing the haze from aerial photos

Becky · #1 07-12-2002, 12:13 PM

Does anyone have any suggestions for removing the haze from aerial photos? The only day the photographer could go up in the airplane, the temperature was about 95 degrees with 90% humidity. This was at 8:00 in the morning! Needless to say, there is quite a bit of haze in the shots. I have tried selecting the blue channel, and replacing it with a corrected blue channel, but it still was hazy. Using Photoshop 7 on windows 2000.

Thanks in advance!

Becky

Doug Nelson · #2 07-12-2002, 12:14 PM

Can we see an example?

jeaniesa · #3 07-12-2002, 12:51 PM

Becky,

Welcome to RetouchPro! It would help to see an example, but I think I know what you are talking about, since my husband came home from the Philippines with some arial shots of Mt. Pinatubo that were washed out because of haze. My immediate reaction was, "Gee - would have been nice if you'd had a polarizer filter when you took the pics." So, I went looking for a Photoshop filter that would act as a polarizing filter after the fact. As it turns out, what I found helped some, but weren't perfect. But, in the hopes that it might help you, here's what I found:

Free action at:
http://www.digitalsecrets.net/secrets/polarizer.html

Nik Color Efex Pro! Photo Design Set (free demo; $99.95 to buy):
http://www.nikmultimedia.com/usa/pro...esignset.shtml

I have a vague memory that I had a third reference, but I can't seem to find it.

Sorry.

Also, if things look really washed out, you might try duplicating the layer and changing the blend mode to multiply (adjust opacity as needed).

Good luck! (And if you are able to attach an image, I might have some more ideas after looking at it.)

Jeanie

Becky · #4 07-12-2002, 01:47 PM

Thanks for the welcome, Jeaniesa.

Here are a couple of samples.

http://www.ksu.edu/ksuphoto/hazy.htm

I will try your suggestions also.

Thanks!

Doug Nelson · #5 07-12-2002, 02:08 PM

I had limited success apply a duplicate layer in multiply mode, then a curves layer with a gradient blend layer mask.

Becky · #6 07-12-2002, 02:47 PM

Doug,

I used the method you suggested, and put it pack on the web site. I used one layer, multiplied at 100% with the gradient mask going from bottom to top. The gradient was 50% gray to 100 % white. Then made duplicate layer of that, set to multipliy at 19% with gradient from bottom to top, 100% black to 100% white to darken the top more without adding anymore contrast to the trees at the bottom.
That seems to work pretty good, but we are hoping that the photographer can go back up on a less hazy day!

Thanks for you help.

Becky

Doug Nelson · #7 07-12-2002, 03:53 PM

That actually looks better than the one I did

jeaniesa · #8 07-12-2002, 04:17 PM

You seem to have figured things out pretty well Becky. I don't think I can improve on what you've done!

Jeanie

Flora · #9 07-13-2002, 06:50 PM

Becky

Hi and welcome to RetouchPRO!

For your "hazy" picture, after correcting the colour using the Curves, I did exactly what Doug did but I repeated it several times applying the gradient to strategic points of the mask.
Here is the result I got:

jeaniesa · #10 07-13-2002, 07:54 PM

WOW!! That's amazing Flora! Good work!

Jeanie

Jakaleena · #11 07-13-2002, 09:12 PM

Hi Becky! Glad to see you here!

Looks like you've gotten great advice.

I just thought I'd add my 2¢ worth too...

I duplicated the background layer and added a layer mask. Then I used the gradient tool on the mask diagonally. I adjusted the levels and color. After that, I selected spots with the lasso tool and blurred the selection with the quick mask and adjusted the contrast and color. To end with, I made a duplicate of the image and changed it to Lab mode and used USM. Then copied that to a new layer on the original image, set to luminosity blending mode, flattened and did a little dodging and burning.

Flora · #12 07-14-2002, 02:27 AM

Hi Jeanie, Jack

Thanks for your words!

I finally managed to get Katrin Eismann book on Photoshop!

I think she is a genius!!!

Jeanie
I downloaded the 'Polarizer' Filter....sounds great! Thank you very much for the Link!

Jack
great work! (as usual

)...I think we followed the same procedure: adjustment layers and 'strategically positioned' gradients which I applied not only to light and shadows, but to colours as well....

Becky · #13 07-15-2002, 06:40 AM

Wow! Thanks everyone for your help. I will get to work today and try your methods. You have been a great help!.

I am so glad I found this site. I can tell it is going to make my life easier!

Howard Smith · #14 02-15-2004, 01:21 PM

I have some slides taken from a mountain top on a good day (100+/- miles viability) but they are hazy in the distance. I am planing to try to cut the distance hazy using the techniques outlined in this thread, but I am unable to fined the free polarize action, listed by Jeaniesa, on the digital secrets site.
Has it now been incorporated into another piece of software? Might there be any other freeware polarizer out there?

Rexx · #15 02-17-2004, 12:16 AM

Hi Howard,

I had a bunch of these photos coming back from Portugal. Sometimes a simple click on Auto in Levels or Curves did the trick. But if there is a sharp foreground, I had to do what Becky and Flora did (Multiply). Not difficult

You get the hang of it quite quickly. At least I did. And since you're working in the Mask, you can just draw the gradient(s) again and again until you get it right. Remember to draw a "short gradient" if you need an abrupt change from foreground to background.

On the enclosed photo I think I had two or three gradients running at different angles, pluss manual mask painting over the trees. It's amazing how you can "save" a photo this way! Just a few minutes per photo