How to convert black and white image to a matrix 100 x 100 ?

Dear all, I have a black and white image that I want to read it as a matrix of size 100 x 100, I need the elements of the matrix to be 1 for black pixels and -1 for the white pixels, could any one help me in how to have the size of the matrix to be 100 x 100 and its elements 1 and -1? thank you

Answer 1

[Andrei Bobrov]

c = [1 0 0 1 1 1 0 1 0 0]

out = ~c*2-1

[sali]

Thanks Andrei for your answer, I could use this after reading the image and convert it to 100x 100 matrix which I did not yet figure it out!