How to convert a matrix having integer entries (+ or -) into binary ?

i have code,

a = -123; % your float point number
n = 16;         % number bits for integer part of your number      
m = 0;         % number bits for fraction part of your number
% binary number
d2b = fix(rem(a*pow2(-(n-1):m),2)); 
% the inverse transformation
b2d = d2b*pow2(n-1:-1:-m).';

sir, this code converts floating point no. (+ or -) to binary. If i have a matrix say A=[1,2,3;-1,-2,5;-5,6,-23], then how to do the same ??

[Abdul Gaffar]

Plz reply

Answer 1

[Ameer Hamza]

This code will work for a matrix A

% for transformation
powers = reshape(pow2(-(n-1):m), 1, 1, []);
d2b = fix(rem(a.*powers, 2)); 
% for inverse transformation
powerReverse = reshape(pow2(n-1:-1:-m), 1, 1, []);
b2d = sum(d2b.*powerReverse, 3);

d2b is 3D matrix. To extract transformation value corresponding to a(i, j) from d2b use squeeze(d2b(i,j,:)).

[Abdul Gaffar]

i am taking

a=imread('lena.png'); m=16; n=16;

and your code, on running it shows error-

Error using  .* 
Integers can only be combined with integers of the same class, or scalar doubles.

Error in dec2bin_mat (line 4)
d2b = fix(rem(a.*powers, 2));

[Ameer Hamza]

images have class uint8. You first need to convert it to double. After imread add

a = double(a);

[Abdul Gaffar]

while using a =double(a); showing error-- Array dimensions must match for binary array op. Error in dec2bin_mat (line 4) d2b = fix(rem(a.*powers, 2));

[Ameer Hamza]

I question you just mentioned a 2D matrix A. It seems that you are reading an RGB image. A color image have 3 dimensions. You first need to use rgb2gray() to convert it to a 2D grayscale image. Try this

a=imread('lena.png');
a = rgb2gray(a);
a = double(a);

[Abdul Gaffar]

Error using .* Integers can only be combined with integers of the same class, or scalar doubles. Error in dec2bin_mat (line 4) d2b = fix(rem(a.*powers, 2));