How to convert array of 1's and 0's to ascii character?

I have an array which at the end of my loop will contain a sequence of 1's and 0's which will contain a hidden message when decoded. I need to find away to convert this array into it's equivalent ascii characters for each segment of 8 bits. I generate this array of 1's and 0's by generating a logical array which I then convert to an integer array (probably unecessary if there is a more direct way). I then tried using dec2bin but I don't know what that does for me. So for example my integer array looks like:

Decode=[01000001] (type int8)

dec2bin - creates a column array of Decode in type char (this needs to be a row vector though).

So in this example the first 8-bits pertain to the decimal value 65 which is ASCII 'A'. At the end of my loop 'Decode' will be a long vector array containing many 8 bit sequences where each 8-bits corresponds to a particular ASCII character which will create a message at the end.

I can not figure out how to get Decode to ASCII.

[KALYAN ACHARJYA]

Is this ?

[Flyers28]

Thanks, I saw that post in my attempt at googling my answer. Couldn't figure out how it applied to what I have. Mostly because I didn't understand what the code was doing in the first place. I'll try again to play around with what was in that post. I ended up doing something similiar though.

I just don't understand what the whole reshape and everything following is doing. But converting my array to a string, removing spaces and using char(bin2dec) as in that link you posted seemed to work for my pseudo code.

I think I am going to skip trying to take the entire array of 1's and 0's and just convert each 8-bits to it's ascii like above, assign that to a variable and continue through the loop concatenating each new character to the last.

[James Tursa]

Please state precisely what you are starting with, then we can suggest the most efficient way to get your final answer, probably without the need of looping. E.g., "Decode is a 50x8 uint8 array of 0's and 1's and I want each row of bit values combined and converted into the equivalent ASCII character". Then give a short example of Decode and the final answer you want from this short example.

[Guillaume]

Also specify if the character set is really ASCII (character codes between 0 and 127 only) or some other character set ,e.g. some 8-bit character set like ISO 8859-1 (latin 1), or a variable length encoding like UTF8.

Note that matlab characters are UTF16.

Answer 1

[David Hill]

bin2dec works off a character array ('10010011'). Convert 1 and 0 array to character array, and remove spaces.

a=num2str(Decode);
a=a(a~=' ');
output=[];
for i=1:9:length(a) %assuming you know that your binary stream is factor of 8 bits long
    output=[output,char(bin2dec(a(i:i+7)))];
end

If you don't need to originally convert to a binary stream, I would stay in a uint8 array (easier to work with).

[Stephen23]

Note that the output should be preallocated before the loop:

https://www.mathworks.com/help/matlab/matlab_prog/preallocating-arrays.html

The loop is not necessary: as this answer notes, bin2dec already works on character arrays.

Answer 2

[Flyers28]

I ended up getting it to work. I was way over complicating it. I appreciate everyones response. Your way is way more efficient however. I have more lines of code then I needed for sure. If this was a way more complicated input I'd probaby bog down my computer with the ineffeciences but for what I needed it to do it worked. I'll see if I can play around with it using your structure during my free time as a learning experiment.

Thanks again everybody

[Anfal D]

Dear Flyers28;

i am working on hiding text message in frames

I recntally have issue on decode (extract) from the char array(contain 0's and 1's) an Ascii letters.

I am trying the answers here but it doesnot work.

can you help me please,

iam using version 2019b