Adjust White color on background

[Sergey Andrianov]

Hi, I need serious help ;)

I take a lot of pictures of different stuff (usually not bigger than 3-5 cm) on a complitely white background. I don't have an extremely professional camera, so i have a problem with color adjustment.

Due to UnPerfect lightening my background colour on the picture (which should be white or at least greyish) comes out bluish.

I can adjust colours using curves. It works for me. Take background colour sample in R G B, let's say it would be 200, 205, 213, go to curves and set the curve so that R(200)=R(205); G(205)=G(205); B(213)=B(205). This way the point i took colour sample from becames perfectly grey 205,205,205.

My problem is that:
1. in different parts of the picture white colour samples are slightly different (i don't consider shades next to actual objects).
2. Pictures come out ligher and darker every time depending on the colour of the object itself.

What i need is to figure out a way to make an automated task which would make my background perfectly grey.

Can anyone give me a hint? :) Or even a full manual on "how to"?

[LenHewitt]

Sergey,

Select the b/g and desaturate from Hue/Saturation - not sure how you can
automate that though, unless the objects are very distinct from all areas of
the background