Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: ErikKaffehr on June 19, 2015, 03:37:24 am

Title: I feel dehaze should be a local adjustment
Post by: ErikKaffehr on June 19, 2015, 03:37:24 am
Hi,

I tested "dehaze" and it may work, but I feel that it should have been a local enhancement and not a global one. Close objects need little "dehaze" and distant ones a lot more.

Best regards
Erik
Title: Re: I feel dehaze should be a local adjustment
Post by: Schewe on June 19, 2015, 08:03:28 am
Yeah, well, Dehaze analyses the entire image to determine the haze so I'm pretty sure the algorithm is not suited to local adjustments. We'll see, but I doubt it will be a local.
Title: Re: I feel dehaze should be a local adjustment
Post by: Bart_van_der_Wolf on June 19, 2015, 09:13:44 am
Quote from: Schewe on June 19, 2015, 08:03:28 am
Yeah, well, Dehaze analyses the entire image to determine the haze so I'm pretty sure the algorithm is not suited to local adjustments. We'll see, but I doubt it will be a local.

I also think it is unlikely to become a local adjustment because it already differentiates between foreground and background, provided that the scene analysis it does leads to that distinction based on the detected amount of haze. There will always be situations that such an automatic analysis (somewhat) fails, but then I think it is already a tool that has to be used with creative caution. If the atmospheric conditions are hazy, one may want to slightly adjust it but not totally remove it.

Total removal of haze would take a roundtrip to e.g. Photoshop and apply it in masked zones. I assume it can be applied as an ACR filter to masked layers. If not, then tools like Topaz Labs Clarity will also get you there.

Cheers,
Bart
Title: Re: I feel dehaze should be a local adjustment
Post by: digitaldog on June 19, 2015, 10:03:37 am
Quote from: Schewe on June 19, 2015, 08:03:28 am
Yeah, well, Dehaze analyses the entire image to determine the haze so I'm pretty sure the algorithm is not suited to local adjustments. We'll see, but I doubt it will be a local.
But what about applying it globally as you point out, then removing it locally?
Title: Re: I feel dehaze should be a local adjustment
Post by: digitaldog on June 19, 2015, 10:16:21 am
So considering the algorithm is analyzing the image, check out this guy's blog who is offering Dehaze presets he built in CC to users of LR6:
http://prolost.com/blog/dehaze
Someone at Adobe needs to know about this Jeff. Unless they don't care.
Title: Re: I feel dehaze should be a local adjustment
Post by: john beardsworth on June 19, 2015, 10:35:41 am
Quote from: digitaldog on June 19, 2015, 10:16:21 am
So considering the algorithm is analyzing the image, check out this guy's blog who is offering Dehaze presets he built in CC to users of LR6:
http://prolost.com/blog/dehaze
Someone at Adobe needs to know about this Jeff. Unless they don't care.

They do know and aren't too worried. I've seen similar preset suggestions in half a dozen places.
Title: Re: I feel dehaze should be a local adjustment
Post by: AlterEgo on June 19, 2015, 10:44:09 am
Quote from: ErikKaffehr on June 19, 2015, 03:37:24 am
I tested "dehaze" and it may work, but I feel that it should have been a local enhancement and not a global one.

+100500
Title: Re: I feel dehaze should be a local adjustment
Post by: AlterEgo on June 19, 2015, 10:46:39 am
Quote from: digitaldog on June 19, 2015, 10:03:37 am
But what about applying it globally as you point out, then removing it locally?
yes. you can continue to use all the image to decide how to calculate it - but to actually apply it just where user paints a local adjustment mask, that's it...
Title: Re: I feel dehaze should be a local adjustment
Post by: digitaldog on June 19, 2015, 11:24:00 am
Quote from: john beardsworth on June 19, 2015, 10:35:41 am
They do know and aren't too worried. I've seen similar preset suggestions in half a dozen places.
Would a preset built this way be suboptimal or would a preset analyzes the image itself and short of the fine granularity of a slider, work?
Title: Re: I feel dehaze should be a local adjustment
Post by: Bart_van_der_Wolf on June 19, 2015, 11:38:00 am
Quote from: digitaldog on June 19, 2015, 11:24:00 am
Would a preset built this way be suboptimal or would a preset analyzes the image itself and short of the fine granularity of a slider, work?

It would be exactly the same effect, for the same setting on the control slider. The DeHaze feature is part of the ACR engine, and they just crippled it for perpetual license customers.

Cheers,
Bart
Title: Re: I feel dehaze should be a local adjustment
Post by: john beardsworth on June 19, 2015, 11:56:08 am
Quote from: digitaldog on June 19, 2015, 11:24:00 am
Would a preset built this way be suboptimal or would a preset analyzes the image itself and short of the fine granularity of a slider, work?

A preset doesn't do any fancy analysis and is just a granular value (see below). If you really wanted granularity, you could have up to 201 dehaze presets to match the slider's -100 to +100 range.

Out of curiosity, I did look into whether one could create a small plugin with a Dehaze slider. One can do this for other adjustments but it looks like Dehaze values can't be set by plugins. That's probably not deliberate on Adobe's part - the Lr6 SDK hasn't been published - but I wouldn't ever release such a plugin.

John

Text of a simple Dehaze preset when viewed in TextEdit or Notepad:
s = {
id = "C5419DBD-95B0-4EAE-9955-0A977E9D1C22",
internalName = "Untitled Preset",
title = "Untitled Preset",
type = "Develop",
value = {
settings = {
Dehaze = -56,
EnableEffects = true,
ProcessVersion = "6.7",
},
uuid = "D62717D1-0BB4-4155-81F2-D0B8D1E39F39",
},
version = 0,
}

Title: Re: I feel dehaze should be a local adjustment
Post by: digitaldog on June 19, 2015, 12:45:10 pm
Thanks John, I don't understand the values you've provided but assuming one could produce 201 presets, is this still affected by the individual images when applied in QD? It just calls a position on the slider and presumably this image by image algorithm adjustment is maintained?

Even if so, the idea of  having 201 presets to move something seems a supreme kludge.
Title: Re: I feel dehaze should be a local adjustment
Post by: john beardsworth on June 19, 2015, 01:12:27 pm
Quote from: digitaldog on June 19, 2015, 12:45:10 pm
Thanks John, I don't understand the values you've provided but assuming one could produce 201 presets, is this still affected by the individual images when applied in QD? It just calls a position on the slider and presumably this image by image algorithm adjustment is maintained?

Even if so, the idea of  having 201 presets to move something seems a supreme kludge.

Yes, obviously absurd. I think the Prolost guy just created a reasonable number of presets.

I'm not quite sure what you're asking in "is this still affected by the individual images when applied in QD?" but those values are the text of a preset which only sets Dehaze to -56. Applying it is just like dragging the slider in Develop, nothing fancier than that.
Title: Re: I feel dehaze should be a local adjustment
Post by: digitaldog on June 19, 2015, 01:23:16 pm
Quote from: john beardsworth on June 19, 2015, 01:12:27 pm
Applying it is just like dragging the slider in Develop, nothing fancier than that.
OK, I understand now, thanks.
Title: Re: I feel dehaze should be a local adjustment
Post by: Schewe on June 19, 2015, 07:46:27 pm
Quote from: digitaldog on June 19, 2015, 10:16:21 am
So considering the algorithm is analyzing the image, check out this guy's blog who is offering Dehaze presets he built in CC to users of LR6:
http://prolost.com/blog/dehaze
Someone at Adobe needs to know about this Jeff. Unless they don't care.

They know...but what are they gonna do about it. Both LR CC & 6 and ACR 9.1 all need to be able to render all of the adjustments in an image-including Dehaze, there is no way to allow rendering only selective adjustments. That would break the pipeline. It's not that they don't care, it more like there's no way to keep it from happing and maintain the integrity of the pipeline.
Title: Re: I feel dehaze should be a local adjustment
Post by: tongelsing on June 23, 2015, 04:36:06 am
It should be a global and a local adjustment and it should be placed next to the Clarity slider.
I used it in a lot of other then landscape images. If you have to lighten up the shadows in a image quite a lot the Dehaze-slider counteract this a little bit in a nice manner and add punch to the whole of the image.
I use it as a new kind of contrast slider mostly in conjunction whit the Shadow slider and I'm very happy with it.