MATLAB: Turn background to one color

image processingimage segmentation

I have an RGB image and I want to do something similar to a binary image. But instead of black and white colors, I want some objects to be white, while the background of the image should be blue. How can I accomplish this?

I've tried using for loops, but not sure how to do iterate through RGB images properly.

Best Answer

Threshold the image and do your thresholding to get your binary image. Then follow Steve's directions if you want the detected regions in the overlay. http://blogs.mathworks.com/steve/2009/02/18/image-overlay-using-transparency/

If you want the blue to be "burned in" to an RGB image, then you need to first get the individual color channels, and then do

redChannel(binaryImage) = 0;
greenChannel(binaryImage) = 0;
blueChannel(binaryImage) = 255;
rgbImage = cat(3, redChannel, greenChannel, blueChannel);

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MATLAB: 8 bit depth RGB image(gif)

Copy and paste this example code:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;
% Change the filename to your filename!
[gifImage cmap] = imread('C:\Users\yourname\Pictures\whatever.gif');
% Display indexed GIF image.
subplot(2,3, 1);
imshow(gifImage);
% Convert to true color RGB image.
rgbImage = ind2rgb(gifImage, cmap);
title('GIF Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
subplot(2,3, 2);
imshow(rgbImage);
title('After conversion to RGB', 'FontSize', fontSize);
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Display the three component color channels.
subplot(2,3, 4);
imshow(redChannel);
title('Red Channel', 'FontSize', fontSize);
subplot(2,3, 5);
imshow(greenChannel);
title('Green Channel', 'FontSize', fontSize);
subplot(2,3, 6);
imshow(blueChannel);
title('Blue Channel', 'FontSize', fontSize);

MATLAB: I have following code of image extraxtion but i got gray scale image output while giving input color image ,how could i get the color image output

I wouldn't do it that inefficient way at all. But that's another issue. Your problem is that you're casting your color image to a logical image, e, and then displaying that e instead of the color image c. Why are you doing that? Also, I apply a colormap after I've displayed the image, not before and I'm not sure if displaying an image will reinitialize the colormap.

I'd do it like this:

rgbImage=imread('new2.png');
% Display the original color image.
subplot(2, 3, 1);
imshow(rgbImage);
title('Original Color Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
binaryImageR = redChannel > 233;
binaryImageG = redChannel > 25 & redChannel < 30;
binaryImageB = blueChannel > 35 & blueChannel < 40;
% Display the binary images.
subplot(2, 3, 2);
imshow(binaryImageR);
title('Red Binary Image', 'FontSize', fontSize);
subplot(2, 3, 3);
imshow(binaryImageG);
title('Green Binary Image', 'FontSize', fontSize);
subplot(2, 3, 4);
imshow(binaryImageB);
title('Red Binary Image', 'FontSize', fontSize);
% Combine
binaryImage = binaryImageR & binaryImageG & binaryImageB;
subplot(2, 3, 5);
imshow(binaryImage);
title('Overall Binary Image', 'FontSize', fontSize);
% Mask the image.
maskedRgbImage = bsxfun(@times, rgbImage, cast(binaryImage,class(rgbImage)));
subplot(2, 3, 6);
imshow(maskedRgbImage);
title('Masked Color Image', 'FontSize', fontSize);

Best Answer

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MATLAB: 8 bit depth RGB image(gif)

MATLAB: I have following code of image extraxtion but i got gray scale image output while giving input color image ,how could i get the color image output

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