MATLAB: How can I handle colors

image analysisimage processingMATLABMATLAB and Simulink Student Suitematlab functionmatrix manipulation

hello I have a code that turns my image of black and white in color but I am stuck at the level of color segment I want the red part to be black

(attached image)

function [ ] = imageLabels(image)
figure,imagesc(image)
colormap(hsv)
axis image;
hold on;
for K = 1 : 4; hidden_h(K) = surf(uint8(K-[1 1;1 1]), 'edgecolor', 'none'); end
hold off
uistack(hidden_h, 'bottom');
legend(hidden_h, {'tree','rock','water'} )
axis off;
end

Best Answer

Possibly, this will do what you want:

matcontent = load('C1fig.mat');  %load ans variable (bad name!) as matcontent.ans
greyimage = matcontent.ans;      %the grey image as a 2D matrix in the range 0-1
greenimage = cat(3, zeros(size(greyimage)), greyimage, zeros(size(greyimage)));  %make the greyimage the 2nd channel of a RGB image
imshow(greenimage);

Related Solutions

MATLAB: Black and white image

Try this

[counts, grayLevels] = imhist(grayImage, 256);
if sum(counts(2:end-1)) > 0
  % It's not pure black and white
end
% Get map of non-0 and non-255 pixels
grayPixels = grayImage > 0 & grayImage < 255;
% Get pure black and white image
bw = grayImage; % Initialize

bw(grayPixels) = 0; % Zero out any gray pixels.
% Get gray pixels only
grayOnly = grayImage; % Initialize
grayOnly(~grayPixels) = 0; % Zero out any pure 0 or pure 255 pixels.

MATLAB: Problem displaying a satellite image

That's not a gray scale image you attached, it's an RGB image. So try this

rgbImage = imread('C1fig.jpg');
whos rgbImage
subplot(2, 1, 1);
imshow(rgbImage);
title('Original RGB image C1fig.jpg');
axis('on', 'image');
impixelinfo
mask = rgbImage(:, :, 1) == 0;
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
redChannel(mask) = 255;
greenChannel(mask) = 0;
blueChannel(mask) = 0;
% Recombine separate color channels into a single, true color RGB image.

rgbImage = cat(3, redChannel, greenChannel, blueChannel);
subplot(2, 1, 2);
imshow(rgbImage);
axis('on', 'image');
impixelinfo
title('Altered RGB image');

If it really is a gray scale image, you can try this:

grayImage = imread('C1fig.jpg');
if ndims(grayImage) == 3;
	grayImage = rgb2gray(grayImage);
end
whos grayImage
subplot(2, 1, 1);
imshow(grayImage);
title('Original image C1fig.jpg');
axis('on', 'image');
impixelinfo
mask = grayImage == 0;
% Initialize the individual red, green, and blue color channels.
redChannel = grayImage;
greenChannel = grayImage;
blueChannel = grayImage;
redChannel(mask) = 255;
greenChannel(mask) = 0;
blueChannel(mask) = 0;
% Recombine separate color channels into a single, true color RGB image.
rgbImage = cat(3, redChannel, greenChannel, blueChannel);
subplot(2, 1, 2);
imshow(rgbImage);
axis('on', 'image');
impixelinfo
title('Altered RGB image');

Best Answer

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MATLAB: Black and white image

MATLAB: Problem displaying a satellite image

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