How to add AWGN white noise in a 2d vector

mixed_ocr is a vector of 350x250. im receiving an error with the following code..please help

CODE :

clc
A1 = load('mixed_ocr.mat');
mixd_ocr = (A1.mixed_ocr);
y = awgn(mixd_ocr,10,'measured');

ERROR:

??? Error using ==> plus
Integers can only be combined with integers of the same class, or scalar doubles.

Error in ==> awgn at 272
y = sig+wgn(size(sig,1), size(sig,2), noisePower, 1, state, pMode, opType);

Error in ==> PARTA_Q3 at 4
y = awgn(mixd_ocr,10,'measured');

[Nishitha Ayyalapu]

It works fine with the data I worked on:

A = rand(350,250);
y = awgn(A,10,'measured');

The problem might be in the .mat you loaded. More information on your 350x250 you loaded would help to resolve the error.

Answer 1

[Wayne King]

I think you should try casting the mixd_ocr matrix to double.

mixd_ocr = double(mixd_ocr);

If you execute

class(mixd_ocr) % before you cast to double

You'll probably see the issue. For example:

X = randn(350,250);
X = int8(X);
y = awgn(X,10,'measured');

gives the same error you are seeing.