Dear All,

I have just uploaded to the Gimp plug-in repository a plug-in that enables you to modify the color temperature of a photo. I can be used to correct the bluish cast in overcast photos, or even (to some extent) the red cast in photos taken under incandescent light with the camera set to daylight. At least for me, the plugin works better than playing around with the levels and curves menus by hand, in part because the color transformations are done in the linear (rather than gamma-corrected) color space, and use black-body color temperature as reference.

Anyway, I had been wishing for a long time for a tool to modify the color temperature of an image, and now there is one! http://registry.gimp.org/plugin?id=8730 I hope it can be useful to others! Give it a try, it has extensive help included.

All the best,

Luca

This is strange - I defined it so that it goes under "Tools/Color Tools" for version 1.2 (It used to be Layer/Colors). That's where all the other color manipulation options are... (The script-fu menu seems to be on things other than color manipulation).

Can you check which version you are running? Oh btw, I developed this under Gimp 2.2; I have no idea whether other versions of Gimp have different menu arrangements, so that the plugin does not find a home.

Let me know...

Luca

On 12/12/06, Alexander Rabtchevich wrote:

Thank you, Luka

The plug-in seems to work! I have only one problem with it now - it doesn't define a place to be put in the register procedure. I added /Script-Fu/Enhance/ before the Convert Color Temperature and could find it :). I use GIMP 2.3.12 on Windows.

Luca de Alfaro wrote:

Dear All,

I have just uploaded to the Gimp plug-in repository a plug-in that enables you to modify the color temperature of a photo. I can be used to correct the bluish cast in overcast photos, or even (to some extent) the red cast in photos taken under incandescent light with the camera set to daylight.
At least for me, the plugin works better than playing around with the levels and curves menus by hand, in part because the color transformations are done in the linear (rather than gamma-corrected) color space, and use black-body color temperature as reference.

Anyway, I had been wishing for a long time for a tool to modify the color temperature of an image, and now there is one! http://registry.gimp.org/plugin?id=8730 I hope it can be useful to others! Give it a try, it has extensive help included.

All the best,

Luca

--
With respect
Alexander Rabtchevich

I am new to writing plugins - am I violating some convention by putting my plugin in Tools/Color Tools? It seems the best category from the point of view of fit, but perhaps I should use Script-Fu/Color Tools/ instead? I don't like the "enhance" category, as it seems to be very ill-defined (well, all we do is enhancing, isn't it? surely "curves" is also enhancing...).

Others on the list, please feel free to advise. Either way, it's a trivial change for me to do.

Luca

(sorry for the re-send; I was using the wrong email address)

On 12/12/06, Alexander Rabtchevich wrote:

Ok, it appears exactly where you said. I simply wasn't able to find it there.

Luca de Alfaro wrote:

This is strange - I defined it so that it goes under "Tools/Color Tools" for version 1.2 (It used to be Layer/Colors). That's where all the other color manipulation options are... (The script-fu menu seems to be on things other than color manipulation).

Can you check which version you are running? Oh btw, I developed this under Gimp 2.2; I have no idea whether other versions of Gimp have different menu arrangements, so that the plugin does not find a home.

Let me know...

Luca

--
With respect
Alexander Rabtchevich

Hi,

I took Sven's advice, and moved the plug-in to Filters/Colors/Convert Color Temperature.
Indeed Sven is right, that is a more logical place, and since the new model going forward is to
have plugins register to the appropriate area, rather than "script-fu", I went ahead with that.

BTW, I like the idea of configurable menus. It would be great if Gimp stored the menu configuration in an easy to locate file (as Gimp does now for most things), making it easy to copy the file from one machine to the other to keep the menus consistent.

Best,

Luca

On 12/13/06, Sven Neumann wrote:

Hi,

On Wed, 2006-12-13 at 11:00 +0200, Alexander Rabtchevich wrote:

Sven, I've seen you newest image window on the blog. Does it mean there will be no script-fu or even tiny-fu top menu entry at all?

Indeed. Well, at least not with the set of plug-ins and scripts that ships with 2.4. Old scripts will still be able to register in the old menu locations and that will cause the respective menu branches to be created. We expect that people will adjust their scripts and plug-ins to the new menu hierarchy sooner or later.

Sven

Not as a script. It does not depend on the script, but on how Gimp calls the script. Unfortunately, the script is called only when you press OK, and not when you modify a control.
It's a pity, and I wonder if scripts could be called differently - at each change of some control - in some future version of Gimp.

Luca

On 12/15/06, norman wrote:

Simple: download it, and put it into the ~/.gimp-2.2/scripts/ directory.
That's it. Then start Gimp, and you will find it in Filters/Colors/Whitebalance or Filters/Colors/Convert Color Temperature.

Thank you, I found it in Filters/Colours/Convert Colour Temperature. It certainly is effective.

Would it be possible to make it show the effect as sliders are moved before having to click OK.

Regards

Norman