Retinex and improving brightness with no color losses
The Retinex is improving brightness of color images, by computation of the illumination image. A resulting gamma correction take care of light conditions. The color image maintain all his colors, this was not the case with classic gamma.
The implementation is based on Kimmel's Variational Retinex(Spie 2002). I augment the paper by adding an YIQ variant.
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| Lena(384x384) in Color |
Gamma 1.6 |
Homomorphic filter+Gamma 1.6 |
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| YIQ Retinex on Y channel |
HVS Retinex on V channel |
Histogram Equalisation |
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| RGB Retinex alpha=0.03, beta=0.25 gamma=1.6 |
RGB Retinex alpha=0.2, beta=0.0 saturates |
RGB Retinex alpha=0.0, beta=0.4 contrast |
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