how to write this equation in Matlab?? please help

where Ig(x) is an image (matrix

Answer 1

[Bob Thompson]

sigma = (I/eta).*sum(sqrt(ln((Imax(range)+Imin(range))./(Imax(range)-Imin(range))));

Something like this. Your 'range' is going to be the different values of x you want. Most everything else should just be filling in variables.

[ghada sandoub]

thanks alot.. but as i mentioned in my question the term Ig(x) refers to an image(i.e. considered as a matrix in matlab) and x refers to each pixel in image or each element in matrix

so, how to apply this summation on each (x). is the function ( sum) is sufficient to mean that i will apply this equation on each x in the matrix and finally calculate the summation of them??

[Bob Thompson]

You can apply the summation across multiple x values by defining your 'range' to cover those values. sum() just adds up all the values of the interior array.

You can define a range in matlab using index notation.

[ghada sandoub]

@ Bob Nbob

i applied this form for the equation

sigma = (I/eta).*sum((log(( double(Imax) + double(Imin )) ./ ( double(Imax) - double(Imin ))) ).^ -0.5) ;

where : Imax and Imin are matrices with arguments of type uint8 , but i met this error in matlab

and when i used * instead of .* i met this error

can you help me to fix this error