MATLAB: LSB insertion on RGB image

digital image processingimage analysisimage processinglsb

I would like to know how one would

Check the value of the LSB for each channel (R,G,B)
Change the value (1->0 or 0->1)

Using 24-bit image ( 8 bit for each channel)

Best Answer

See this:

m=magic(5)
lowestBits = rem(m, 2)
m =
    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9
lowestBits =
     1     0     1     0     1
     1     1     1     0     0
     0     0     1     0     0
     0     0     1     1     1
     1     0     1     0     1

So you'd do

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Get LSB's of each pixel.
redLsb = rem(redChannel, 2);
greenLsb = rem(greenChannel, 2);
blueLsb = rem(blueChannel, 2);

Related Solutions

MATLAB: Create new binary image from pixel values of another image

Yes it is very simple - just one single line. Simply say:

M_matched = M == matchValue;

Where M is your input matrix, matchValue is the value you want to find (e.g. 13), and M_matched is the output matrix. M_Matched is a logical matrix (which is the data type of "binary" images). A logical (binary) matrix is convenient because you can then use it for logical indexing to extract certain values from a matrix. For example you can say

M_extracted = M(M2);

M_extracted will be 13 in your example but it could be several 13's if you have more than one 13 or other values if you use ">=" instead of "==" in my first line of code.

But you can also cast M_matched to int32 or double or whatever you want, if you need to do that.

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);

Best Answer

Related Solutions

MATLAB: Create new binary image from pixel values of another image

MATLAB: 8 bit depth RGB image(gif)

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