Image profile intensity for many pixels

Hi,

I am working in the images and I was taken the image profile for these images.

What I want to do is I want to take many pixels along the line segment. As you can see in the attched image, I took the imgae profile using improfile to plot the intensity along the selected line (black line). It seems to me that the line onle slected one pxiel vaule. I want to take many pixels in which cover the whole green circle (in the image) alnge the line profile.

[x,y] = ginput(); % for selection

[cx, cy, porifle, xi,yi] = improfile(x,y,image,x',y','bicubic'); % take the image profile

plot(cx',porifle,'k','LineWidth', 3); %to plot the intnesity along the line

Answer 1

[Image Analyst]

DON'T name your image "image" since that is the name of a built in function.

You can do

% Get profile along that line and plot it.

horizontalProfile = grayImage(row, :);

Full Demo below:

% Demo by Image Analyst
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 22;
markerSize = 40;
%--------------------------------------------------------------------------------------------------------
%    READ IN IMAGE
folder = [];
baseFileName = 'cameraman.tif';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
    % The file doesn't exist -- didn't find it there in that folder.
    % Check the entire search path (other folders) for the file by stripping off the folder.
    fullFileNameOnSearchPath = baseFileName; % No path this time.
    if ~exist(fullFileNameOnSearchPath, 'file')
        % Still didn't find it.  Alert user.
        errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
        uiwait(warndlg(errorMessage));
        return;
    end
end
grayImage = imread(fullFileName);
% Get the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels > 1
    % It's not really gray scale like we expected - it's color.
    fprintf('It is not really gray scale like we expected - it is color\n');
    % Extract the blue channel.
    grayImage = rgb2gray(grayImage);
end

%--------------------------------------------------------------------------------------------------------
% Display the image.
subplot(2, 1, 1);
imshow(grayImage);
impixelinfo;
axis('on', 'image');
title('Original Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Update the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(grayImage)
% Maximize window.
g = gcf;
g.WindowState = 'maximized';
drawnow;

%--------------------------------------------------------------------------------------------------------
% Ask user to click a line.
uiwait(helpdlg('Click the line you want the profile of.'))
[x, y] = ginput(1);
row = round(y);
% Display line over image.
yline(row, 'Color', 'r', 'LineWidth', 2)

%--------------------------------------------------------------------------------------------------------
% Get profile along that line and plot it.
horizontalProfile = grayImage(row, :);
subplot(2, 1, 2);
plot(horizontalProfile, 'b.-', 'LineWidth', 2)
grid on;
caption = sprintf('Profile of line #%d', row);
title(caption, 'FontSize', fontSize)

[Sara]

Thank you for your help