How to convert jpg matrix to binary matrix

Hi!

I would like to send an image with a LED, and to do that first I need to read the .jpg image with imread(), but here as a result I get a matrix with decimal elements. Later, for sending the image I will need only binary elements (1-LED is ON, 0-LED is OFF). I was thinking of using the dec2bin() conversion and the result I can store in a new matrix as a string (since it has more elements) and at the sending I just run through each string with a loop and turn the on/off depending on the 0/1 values, but the problem is that after the dec2bin() conversion I will get different sized strings and the receiver shouldn't know these sizes. Is there any other solutions for this problem?

Thank you so much.

Answer 1

[Star Strider]

Try the im2bw or the imbinarize functions in the Image Processing Toolbox. See the documentation on them for necessary details.

[Bence Salanki]

Thank you very much for your answer. The thing is that I don't want to loose the color information and the functions that you suggested are converting the image into black&white.

Answer 2

[Image Analyst]

Here's one approach:

for k = 0 : 255 % Show what happens for every gray level.
  thisString = dec2bin(k);
  string8 = '00000000';
  string8(end-length(thisString)+1:end) = thisString
end

Now all the pixels will be 8 characters, with leading zeros if necessary.

[Bence Salanki]

Thank you very much, it works perfectly!

Answer 3

[Walter Roberson]

dec2bin(k, 8)

gives a fixed number of outputs.