How can i convert YCBCR image to binary image.

I am making a project using image processing and i need to convert the rgb image to YCBCR and then convert it to binary image.

Answer 1

[Image Analyst]

There are functions rgb2ycbcr() and imbinarize().

If those don't work, read this link and write back.

[Sarmad Paracha]

i have converted the image from rgb to ycbcr but im having issue using the binary function. Error in Untitled5 (line 8) BW = imbinarize(I);

[Image Analyst]

Then you must have an antique version of MATLAB. Try just thresholding one of the channels

ycbcr = rgb2ycbcr(rgbImage);
yChannel = ycbcr(:,:,1);
binaryImage = yChannel > 0.5;

[Sarmad Paracha]

I dont think 2017a should be consired "antique". here is the code i am trying to write.

e
RGB= imread('1.tif');
figure
imshow(RGB);
RGB(:,:,2) = 0;
figure
image(RGB);
YCBCR = rgb2ycbcr(RGB);
figure
imshow(YCBCR);

till this command there is no error. but when i try to convert ycbcr to binary it gives me that error. Is there any function for that which i should be saving first ?

[Image Analyst]

imbinarize() was introduced in R2016a so I'm not sure why you had an error running it. Unfortunately you forgot to post the second half of the error message - what the actual error was.

Try this code. No guarantee it's being binarized in the way that you like though.

RGB = imread('peppers.png');
subplot(3, 3, 1);
imshow(RGB);
title('Original Image', 'FontSize', 20);
% For some reason, set the green channel to black.
RGB(:,:,2) = 0;
subplot(3, 3, 2);
imshow(RGB);
title('Now with Green Channel Erased', 'FontSize', 20);

% Convert to YCbCr
YCBCR = rgb2ycbcr(RGB);
yChannel = YCBCR(:, :, 1);
cbChannel = YCBCR(:, :, 2);
crChannel = YCBCR(:, :, 3);
subplot(3, 3, 4);
imshow(yChannel, []);
title('Y Image', 'FontSize', 20);
subplot(3, 3, 5);
imshow(cbChannel, []);
title('Cb Image', 'FontSize', 20);
subplot(3, 3, 6);
imshow(crChannel, []);
title('Cr Image', 'FontSize', 20);
% Now binarize with imbinarize, introduced in R2016a
binaryY = imbinarize(yChannel);
binaryCb = imbinarize(cbChannel);
binaryCr = imbinarize(crChannel);
subplot(3, 3, 7);
imshow(binaryY, []);
title('Y Image Binarized', 'FontSize', 20);
subplot(3, 3, 8);
imshow(binaryCb, []);
title('Cb Image Binarized', 'FontSize', 20);
subplot(3, 3, 9);
imshow(binaryCr, []);
title('Cr Image Binarized', 'FontSize', 20);

[Sarmad Paracha]

I want to explain you what i am really trying to do. Actually i am trying to do image processing to detect fire using RGB and YCBCR and applying some rules to these color spaces. one of which is to suppress max value of B component so bright light sources are not detected as fire. This is just the initial stage. That is also the reason i am binarizing image and filling holes.I will also be using bounding box and centroid properties. This is the code i have written so far to see how things work.

    RGB= imread('1.tif');
          subplot(3,3,1);
          imshow(RGB);
          RGB(:,:,3) = 0;
          subplot(3,3,2);
          image(RGB);
          YCBCR = rgb2ycbcr(RGB);
          subplot(3,3,3);
          imshow(YCBCR);
          BW = imbinarize(YCBCR);
          subplot(3,3,4)
          imshow(BW)
          title('Original Image Converted to Binary Image')
          BW2 = imfill(BW,'holes');
          subplot(3,3,5)
          imshow(BW2)
          title('Filled Image')

      >> PROJECT1
      Error using imbinarize
      Expected I to be two-dimensional.

      Error in imbinarize>validateImage (line 240)
      validateattributes(I,supportedClasses,supportedAttribs,mfilename,'I');

      Error in imbinarize>parseInputs (line 176)
      validateImage(I);

      Error in imbinarize (line 113)
      [I,isNumericThreshold,options] = parseInputs(I,varargin{:});

      Error in PROJECT1 (line 10)
      BW = imbinarize(YCBCR);

[Sarmad Paracha]

I dont think it is a issue with software it is just the code. I used the image from the examples and binirized it without changing its colour space and it runs

I = imread('coins.png');
subplot(1,3,1);
imshow(I)
title('Original Image')
BW = imbinarize(I);
subplot(1,3,2);
imshow(BW)
title('Binary Image')
BW2 = imfill(BW,'holes');
subplot(1,3,3);
imshow(BW2)
title('Filled Image')

[Image Analyst]

imbinarize() works with gray scale images. "coins.png" is a gray scale image while "1.tif" is NOT.

Note how you tried to binarize YCBCR, a multiband image, while I did not. I binarized just the Y, Cb, or Cr channels alone, which are grayscale. That is why your code did not work while mine did.