adjusting white in a picture

[Fouquet Roger]

good afternoon,

I paint a lot with watercolour on white paper. each time that I take a picture the frame ore te paper colour is not white but grey. normally I could change the setting on my Canon 650D but then the colours of the artwork change as well. so I want to change the grey of the paper into white without changing the colours of my painting. 

I tried with white balans but also the other colours became lighter? thx for a answer

 

[thomaso]

If the paper white appears too gray then there was either not enough light when taking the picture or it was taken underexposed. To adjust this issue you could use related  adjustments (there are various, e.g. exposure, highlights, curves, ...), each offers different UI options, so you may visually check which suits best without changing colors more than wanted. Also the clarity filter influences the lights (but shadows, too). Possibly you will use more than one adjustment or filter and you might use a mask to limit your settings to the gray paper areas only.

White Balance influences mainly colors (brightness/contrast secondary only). If the paper was indeed white (without brownish tint) and the light had a neutral daylight color then the gray color values appear nearly identical (R = B = G). If they don't then White Balance would be a useful adjustment, but it might not enlighten the gray paper white sufficiently.

[firstdefence]

You could try the Selective Colour Adjustment filter, choose white and move the Black slider over to the left. Unchecking the Relative box can give a slightly more pronounced effect.

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[Fouquet Roger]

Thank You so much for the reply's given on my topic, it is very helpfully and will work on it