Hi Timothy,

Timothy Jedlicka bonzopad wrote:

I'm planning on introducing my photoclub to The Gimp and one segment will be on color balance.
Is there any way of doing this with Gimp? I was thinking maybe using guides, with snap-to-guide, but my snap "threshold" is apparently too low. Any other ideas?

There are color-pickers (white, black and grey for all channels, and white andblack per channel (including the value channel) in the levels tool dialog. The grey tool is for selecting a grey point (that is, a point with gamma 0) - this is very useful for correcting colour casts where the colour cast is clearest on a light grey or dark grey.

The white and black point color pickers do the same thing, except they fix the white and black points.

This is all for 2.0 pre-releases, these functions are not available in 1.2.x.

Cheers, Dave.

Hi,

Timothy Jedlicka bonzopad writes:

I'm planning on introducing my photoclub to The Gimp and one segment will be on color balance. My co-presenter is using PhotoShop. PS has a nice feature that allows you to set several "reference points" - click on a section you consider "grey" and it will set anchor point/reference point 1 with the RGB values. Click on a part you consider white - and you have ref point 2. Now apply a color correction and see how your reference points change their RGB values.

If you click into the image with the Curves tool active, you get the color value indicated in the Curve dialog. You can only ever set a single point though, but perhaps this helps.

Sven

I've been using the color pickers (in 2.0pre), but I want to show some of the magic behind the scenes - showing how the RGB values change as you color correct. The concept of reference points also helps when trying to assess and manipulate exposure latitude - marking reference points then comparing them is useful when manipulating photos.

In a sense it is a way to apply Ansel Adam's zone system in the digital world. (but don't take this to mean I actually understand the zone-system, it just makes me sound photographically smart *grin*)

On Wed, 10 Mar 2004, "Dave" == Dave Neary wrote:

Dave> There are color-pickers (white, black and grey for all channels, and Dave> white andblack per channel
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Timothy Jedlicka, bonzo@lucent.com, 1-630-713-4436, AOL-IM=bonzowork Network Entomologist, Lucent Technologies, Testers For Hire

Hi,

"Timothy E. Jedlicka - wrk" writes:

I've been using the color pickers (in 2.0pre), but I want to show some of the magic behind the scenes - showing how the RGB values change as you color correct. The concept of reference points also helps when trying to assess and manipulate exposure latitude - marking reference points then comparing them is useful when manipulating photos.

This sounds quite useful to me. It would be nice if you could open an enhancement request in our bug-tracker at bugzilla.gnome.org. Please try to describe the feature as detailed as possible. Once the bug report has been created, you can also attach screenshots and/or mockups of a possible user interface. This would make it more likely that such a feature is being added in a future version of The GIMP.

Of course attaching a patch would make it even more likely ;)

Sven

Press release looks good. I would change the phrase "channels and layers" to "channels, layers and masks". Or somehow advertise that Gimp has masks (something that Photoshop Elements 2.0 is lacking btw). -----
Timothy Jedlicka, bonzo@lucent.com, 1-630-713-4436, AOL-IM=bonzowork Network Entomologist, Lucent Technologies, Testers For Hire