Digital image processing method and for brightness adjustment of digital images

A method of producing a final image, comprising the steps of:

• a) generating one or more pseudo luminance values from an original image according to the relationship,
• L=αR+βG+δB, where R, G ,B represent red, green and blue
• components of the original image, and α≧β>δ≧0;
• b) using the pseudo luminance values (L) to calculate a brightness balance value;
• and
• c) using the brightness balance value and the original image to produce the final image.

An apparatus for calculating a brightness balance value for an original image having contribution from the visible spectrum of wavelengths including red, green, and blue wavelengths comprising:

• a) means for generating one or more pseudo luminance values from the original image wherein
• (i) the pseudo luminance value contribution from the red wavelengths is greater than or equal to the contribution from the green wavelengths;
• (ii) the pseudo luminance value contribution from the green wavelengths is greater than the contribution from the blue wavelengths;
• (iii) the pseudo luminance value contribution from the red and green wavelengths are greater than zero;
• and
• (iv) the pseudo luminance value contribution from the blue wavelengths is greater than or equal to zero;
• and
• b) means for using the pseudo luminance values to calculate a brightness balance value.