Photoshop "Curves" dialog - what's the mathematics behind?

I'd like to draw a curve as shown in the below image:
http://www.sunlitgreen.com/screenshots/images/SGPE_screensho t_03.jpg
It's cool and I like it so much.

Someone told me that's exactly the same as in Photoshop and GIMP. But I failed to find usefull information in their online documentation.

Any idea how to draw such a "smooth curve"?
Viz. given a couple of control points, to darw a curve connecting all of them.

Do a google for bicubic spline - that's the type of curve that is used. --
Mike Russell - www.curvemeister.com

Hi,

I'd like to draw a curve as shown in the below image:
http://www.sunlitgreen.com/screenshots/images/SGPE_screensho t_03.jpg

It's cool and I like it so much.

Someone told me that's exactly the same as in Photoshop and GIMP. But I failed to find usefull information in their online documentation.

Any idea how to draw such a "smooth curve"?
Viz. given a couple of control points, to darw a curve connecting all of them.

Thanks.

On Dec 14, 2:57 am, "Mike Russell" <
MOVE> wrote:

I'd like to draw a curve as shown in the below image:
http://www.sunlitgreen.com/screenshots/images/SGPE_screensho t_03.jpg

It's cool and I like it so much.

Someone told me that's exactly the same as in Photoshop and GIMP. But I failed to find usefull information in their online documentation.

Any idea how to draw such a "smooth curve"?
Viz. given a couple of control points, to darw a curve connecting all of them.

Do a google for bicubic spline - that's the type of curve that is used. --
Mike Russell -www.curvemeister.com

Thanks for the information.