Convert image to a binary stream

I am working on error control in WMSNs. I want to transmit a video through binary symmetric channel with error probability P. So I have frames (images) in each GoP which are shown by a matrix.

Each matrix element have decimal value which might be positive or negative. As explained [here][1] I need to convert this whole matrix to a binary stream. I used

 m = reshape(dec2bin(typecast(b(:),'uint8'),8).',1,[]);

for converting elements to binary streams but I cannot get back the exact number using

b_recovered = reshape(typecast(uint8(bin2dec(reshape(m,8,[]).')),'double'),size(b));

On the other side, for sending this matrix through binary symmetric channel, I have to convert the whole matrix to just one bit stream which I'm not sure how to do that. And convert them to a matrix of measured values of a image again.

Answer 1

[GEEVARGHESE TITUS]

The following code will give the original values back

b=imread('coins.png');
m = reshape(dec2bin(typecast(b(:),'uint8'),8).',1,[])';
c2= reshape(str2num(m),8,[])';
c3=c2*(2.^(size(c2,2)-1 :-1:0))';
c4=uint8(reshape(c3,[size(b,1) size(b,2)]));
err=c4-b;% zeros indicating the values are same