binary bits xor operation

I have 1 1 0 1 1 0 1 0 8bits binary number now i have to do xor operation to that binary values from the 4th bit to 8th bit and finally i have to get 1 or 0 as output. i used for loop but its taking time, any other solutions for fastest way?

A=imread('C:\Users\asus\Desktop\lena.png') %read image

x=de2bi(A,8);

for i=1:65536

k=3

for j=1:1

k=k+1

z1=xor(x(i,k),x(i,k+1))

z1=xor(z1,x(i,k+2))

z1=xor(z1,x(i,k+3))

z1=xor(z1,x(i,k+4))

end

end

Answer 1

[BhaTTa]

For performing an XOR operation on specific bits of binary numbers efficiently, without using a loop for the bit-wise operation, you can take advantage of MATLAB's vectorized operations. Given that you're interested in XORing bits from the 4th to the 8th bit of each 8-bit binary number, you can achieve this with a more direct approach.

Given that x is a matrix where each row represents an 8-bit binary number (as obtained from de2bi function on an image), you can directly perform the XOR operation across the columns of interest. Here's how you can do it efficiently:

% Assuming x is obtained from de2bi(A,8)
% A = imread('C:\Users\asus\Desktop\lena.png'); % Example for reading image
% x = de2bi(A,8); % Convert image to binary representation

% Directly perform XOR operation on the 4th to 8th bits
result = x(:,4); % Initialize result with the 4th column
for k = 5:8 % Loop from the 5th to the 8th column
    result = xor(result, x(:,k)); % Perform XOR operation
end

% 'result' now contains the XOR result for each row

This method initializes result with the 4th column of x and then iteratively performs the XOR operation with the next columns (5th to 8th). This way, you avoid the inner loop entirely and only iterate through the columns once.