Re: [darktable-dev] haze removal default values

[Andreas Schneider]

On Friday, 1 November 2019 21:26:27 CET Heiko Bauke wrote:

> > A PR would be nice and we can let Heiko discuss this here.
> 
> I was not able to work and darktable and to follow the list for some
> time.  Sorry for the late reply.
> 
> I have seen that your patch already made it into darktable.  I
> completely agree (with the more practical experience today) that the
> default values are almost always too strong, in particular with the
> recent changes in pixel pipe (ordering of modules, basecurve replaced by
> filmic (rgb)).  Therefore, I am absolutely fine with the change of
> default values.

Thanks Heiko!


___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal default values

[Heiko Bauke]

Hi,

Am 15.09.19 um 18:03 schrieb Pascal Obry:

Hi Andreas,


the haze removal default values are in 99% of the cases too strong. Is there a
reason that they are this strong?

My suggestions for default values would be:

strength: 0.15
distance: 0.200


I tend to agree and see the same issue on my side. I would keep
strength at 0.20 though.

A PR would be nice and we can let Heiko discuss this here.


I was not able to work and darktable and to follow the list for some 
time.  Sorry for the late reply.


I have seen that your patch already made it into darktable.  I 
completely agree (with the more practical experience today) that the 
default values are almost always too strong, in particular with the 
recent changes in pixel pipe (ordering of modules, basecurve replaced by 
filmic (rgb)).  Therefore, I am absolutely fine with the change of 
default values.



Heiko



--
-- Number Crunch Blog @ https://www.numbercrunch.de
--  Cluster Computing @ https://www.clustercomputing.de
--  Social Networking @ https://www.researchgate.net/profile/Heiko_Bauke
___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal default values

[Pascal Obry]

Hi Andreas,

> the haze removal default values are in 99% of the cases too strong. Is there 
> a 
> reason that they are this strong?
> 
> My suggestions for default values would be:
> 
> strength: 0.15
> distance: 0.200

I tend to agree and see the same issue on my side. I would keep
strength at 0.20 though.

A PR would be nice and we can let Heiko discuss this here.

-- 
  Pascal Obry /  Magny Les Hameaux (78)

  The best way to travel is by means of imagination

  http://www.obry.net

  gpg --keyserver keys.gnupg.net --recv-key F949BD3B

___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal

[Aurélien PIERRE]

Is it different from using the local contrast module or the equalizer ?

*Aurélien PIERRE*
aurelienpierre.com 


Jason Polak:
> As a user of darktable who also follows the dev list, this looks 
> really good. Yesterday I found a shot that I thought could use a 
> little of this module. Another option with it also may be to use a 
> parametric mask to only target the brighter areas of the image,
> which is often where the haze occurs.
> 
> In any case, I hope to try this module.
> 
> Jason
> 
> On 2017-02-21 08:02 AM, Heiko Bauke wrote:
>> haze removal means basically to remove the diffuse background
>> light that is reflected by the haze in the into the direction of
>> the camera.  Thus the image gets slighty darker.  This is similar
>> to when one reduces the brightness in sky regions to get a nice
>> blue sky.
>> 
>> One should be aware that the automatic haze removal module is not a
>> magic bullet.  It may even lead to undesirable artifacts, depending
>> on the input image and the chosen parameters.  The quality of the
>> final image depends of the input image of course. Garbage in,
>> garbage out. It is beneficial, when the RAW image is well-exposed.
>> Thus, the example that I have shown before might not be optimal to
>> promote the haze removal module.  Furthermore,  best results are
>> expected when the haze removal module is combined with other
>> modules.  For example, I would start to remove the haze from an
>> image using the haze removal module and then increase the clarity
>> via the equalizer and enhance the colors by the velvia module and
>> possibly further modules.
>> 
>> Nevertheless, I think the haze removal module will be a powerful 
>> and valuable tool that can help to improve hazy images and gives 
>> very good results in many cases.
>> 
>> 
>> Heiko
>> 
>> 
> ___
>
>
> 
darktable developer mailing list
> to unsubscribe send a mail to 
> darktable-dev+unsubscr...@lists.darktable.org
> 
___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal

[Heiko Bauke]

Dear Pascal,

Am 19.02.2017 um 18:42 schrieb Pascal Obry:

Great news! Looks promising!

I've noticed that some parts get very dark and quite underexpose. We
can see that under the bridge and on the bank of the river.


haze removal means basically to remove the diffuse background light that 
is reflected by the haze in the into the direction of the camera.  Thus 
the image gets slighty darker.  This is similar to when one reduces the 
brightness in sky regions to get a nice blue sky.


One should be aware that the automatic haze removal module is not a 
magic bullet.  It may even lead to undesirable artifacts, depending on 
the input image and the chosen parameters.  The quality of the final 
image depends of the input image of course.  Garbage in, garbage out. 
It is beneficial, when the RAW image is well-exposed.  Thus, the example 
that I have shown before might not be optimal to promote the haze 
removal module.  Furthermore,  best results are expected when the haze 
removal module is combined with other modules.  For example, I would 
start to remove the haze from an image using the haze removal module and 
then increase the clarity via the equalizer and enhance the colors by 
the velvia module and possibly further modules.


Nevertheless, I think the haze removal module will be a powerful and 
valuable tool that can help to improve hazy images and gives very good 
results in many cases.



Heiko


--
-- Number Crunch Blog @ https://www.numbercrunch.de
--  Cluster Computing @ http://www.clustercomputing.de
--   Professional @ https://www.mpi-hd.mpg.de/personalhomes/bauke
--  Social Networking @ https://www.researchgate.net/profile/Heiko_Bauke
___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal

[David Vincent-Jones]

I pulled the attached off a recent Harry Durgin Weekly Edit and find it
to be quite effective.

David



On 02/19/2017 09:42 AM, Pascal Obry wrote:
> Great news! Looks promising!
>
> I've noticed that some parts get very dark and quite underexpose. We
> can see that under the bridge and on the bank of the river.
>
> Cheers,
>


___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal

[Pascal Obry]

Great news! Looks promising!

I've noticed that some parts get very dark and quite underexpose. We
can see that under the bridge and on the bank of the river.

Cheers,

-- 
  Pascal Obry /  Magny Les Hameaux (78)

  The best way to travel is by means of imagination

  http://www.obry.net

  gpg --keyserver keys.gnupg.net --recv-key F949BD3B
___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org

Re: [darktable-dev] haze removal

[Maurizio]

Wow Heiko, it looks very promising!
Maurizio


In data domenica 19 febbraio 2017 18:21:02 CET, Heiko Bauke ha scritto:
> Dear Darktable developers,
> 
> I would like to announce my implementation of an automatic haze removal
> module for darktable.  The attached screenshot may give you first
> impressions.  You can get the code from
> https://github.com/rabauke/darktable/
> I will post a pull request in a few days.  Feedback is welcome.
> 
> I also parallelized the code using OpenMP but did not benchmark the
> parallelization.  Parallelization using OpenCL would take me some time
> because I used OpenCL never before (but Cuda, which has similarities).
> 
> 
>   Heiko


___
darktable developer mailing list
to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org