Dehaze

[Alan9940]

Has anyone else been playing around with the new Dehaze filter? So far, I'm finding that it produces quite bad halos, at default settings, unless I keep the layer opacity below about 50%. Adjusting the size slider up enables me to mitigate the halos somewhat, but I still have to lower layer opacity to about 80%. Anyone else have any findings to pass on?

Thanks!

Best regards,
Alan

[photoken]

Has anyone else been playing around with the new Dehaze filter? So far, I'm finding that it produces quite bad halos, at default settings, unless I keep the layer opacity below about 50%. Adjusting the size slider up enables me to mitigate the halos somewhat, but I still have to lower layer opacity to about 80%. Anyone else have any findings to pass on?

You've pretty much figured it out. Depends on the image, of course, but the default setting of 10% is an OK starting point, and moving the slider somewhat higher (anywhere from 30 to 50) has done the job for most of the images I've tested.

As a side note, there are always unintended uses for a PL tool , so FWIW, DeHaze can be used as part of the process for removing colour casts from images.

[Alan9940]

Hi Ken,

Thanks! To be honest, I was throwing a really tough image at Dehaze--a valley view up near Hetch Hetchy when fires were burning throughout all of Yosemite (quite a bit of smoke around!) I found that I had to use a fairly high size value to avoid halos around the edges of mountain against sky, and then reduce layer opacity a bit. These moves certainly reduced the amount of haze reduction, but with a delicate balance between size/opacity using Dehaze, slight light/shadow adjustment, and a bit of saturation added I was able to pull out a pretty nice image with minimal effort! IMO about the best that could be done here.

Best regards,
Alan

[Herbert123]

This is fun - you can download a pack of hazy photos here:
http://www.kolor.com/images/stories/sol ... ackage.zip

Which is a special Photoshop plugin that also dehazes (and which costs more than the Photoline update )

I really like this new filter.
http://3.static.img-dpreview.com/files/ ... 337358b742
http://3.static.img-dpreview.com/files/ ... f657591073
http://2.static.img-dpreview.com/files/ ... a6df6a8834

Btw, why are our images limited to 640x480px?!!! I cannot even display these (linked!) images!

[MikeFromMesa]

I live in the American southwest and, since much of this area is desert and since the air is often full of a low level of dust, a lot of my images are full of haze, especially if they are shot in the desert itself rather than in some of the cities.

Still, I have found that after I use the Histogram adjustments, the dehazing functionality is much too strong unless, even at its lowest setting, unless I lower the opacity as well. Once I have done that the affect is pretty amazing.

Dxo Optics Pro 10, which is my normal workflow software, incorporated similar functionality in its latest version and I will have to see how the two compare.

[Alan9940]

Hi Mike,

Are you kidding me? We have so much dust in the air out here in the Sonoran Desert that I swear mud falls from the air when it rains!!

Yep, Optics Pro's ClearView is some pretty sweet technology, but since I use other raw converters in addition to OP it's nice to have similar technology in PL. It seems much easier to cause halos with Dehaze vs OP's Clearview, though. But, when ya get the balance just right Dehaze does a pretty acceptable job!

Best regards,
Alan

[Herbert123]

By the way, with a negative opacity the dehaze layer behaves like a "haze" filter - it adds MORE haze. That can also be quite useful under circumstances.

[photoken]

Yet another use is with RAW files -- it can essentially correct the black point. Here's a comparison of the original RAW image when first opened in PL (on the right) with a DeHaze layer at 40% (on the left). No additional RAW adjustments were applied.

raw dehaze.jpg

[Herbert123]

You are indeed correct - I tried it myself on a couple of images without a haze present, and it produces a "clarity" effect. Neat.

[Alan9940]

Ken, Herbert,

Yep, I've used DxO Optic Pro's ClearView technology on many images that don't exhibit any haze; with the right image these algorithms can produce quite amazing results!

And, thanks for the pack of "haze images" from Kolor. I will definitely play around with Dehaze on these pictures to practice its use.

Best regards,
Alan

[Alan9940]

@Herbert123

Been playing around with that pack of haze images from Kolor. I was particularly impressed with what I was able to pull out of "example-04-haze" using two DeHaze layers and a couple of other adjustments, as follows:

1. Duplicated the background layer (not necessary, but my longstanding workflow) and ran the DeHaze filter for a global reduction in the haze.
2. Created a couple of adjustment layers to modify other image characteristics.
3. Merged all existing layers to a new layer, and then ran another DeHaze filter concentrating on the foreground green hill/vegetation.
4. Added a mask to the 2nd DeHaze layer and created a gradient along the top of the hill where it separates from the distant background to reveal the foreground and hide the background.

The final image revealed much depth where the original was quite flat. Very impressive! One of the things I really like about the new DeHaze filter is that it can be applied theoretically as many times as you need, and targeted for specific image areas through masks.

Best regards,
Alan