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Image_Processing_Tool_2 >> Image_Processing_Tool_2 > retinex_McCann

retinex_McCann

Create the raw retinex output

Calling Sequence

Retinex = retinex_McCann(L, nIter)

Arguments

L

Logarithmic single-channel intensity image to be processed. The matrix is having real/integer values.

nIter

Number of retinex iterations. Having integer value.

Retinex

Raw retinex output. The matrix is having same size of L and having real values.

Description

The Retinex model for the computation of lightness was introduced by Land and McCann. The calculations aim to predict the sensory response of lightness. It computes the raw retinex output from an intensity image. The input image is assumed to be logarithmic and in the range 0 to 1. For color images, apply the algorithm individually for each channel. To obtain the retinex 'sensation' prediction, a look-up-table needs to be applied to the raw retinex output. The effect of number of iterations (nIter) is to reduce the contrast of the image.

Examples

I=[3 1 10 5;5 9 4 2;9 12 6 21]; // part of the input image
iter=3;  // number of iterations
output=retinex_McCann(I,iter);

<p class="para">Color constancy is a desirable feature of computer vision and many algorithms have been developed for this purpose. These includes several retinex algorithms. These algorithms receive as input the red/green/blue values of each pixel of the image and attempt to estimate the reflectances of each point.</p>

Authors

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