Comparing a logical matrix and a numerical matrix?

I want to make a function that takes in as input a matrix (orig) and a logical matrix (mask). If the logical at a certain index is 1, I want the value in that same index for the orig equal to what it is. If it is zero, I want the orig to be the value in that index divided by 4.

function [masked] = maskImage(orig, mask)

For example, if

orig = [45 32 145; 88 33 203; 33 231 40] and 

mask = [1 0 1; 1 1 0; 0 1 1], then orig (masked) would become 

[45 32/4 145; 88 33 203/4; 33/4 231 40].

Any help is appreciated.

Answer 1

[Roger Stafford]

Assuming 'mask' really is a logical array the same size as 'orig' do:

   orig = mask.*orig+(~mask).*orig/4;

Otherwise if 'mask' is actually numerical 1's and 0's do:

   orig = (mask==1).*orig+(mask~=1).*orig/4;

Answer 2

[dpb]

masked=orig;                 % all; only the false entries need modification
masked(~mask)=orig(~mask)/4; % so fixup those...

ADDENDUM

And, as Roger says, if the "mask" is numeric, just turn it to logical...

mask=logical(mask);

first.

Answer 3

[Andrei Bobrov]

mask(~mask) = 1/4;
out = orig.*mask;