Image Processing ToolboxMATLABplotprofile
binaryImage = grayImage > 150;maskedImage = zeros(size(grayImage)); % Initialize.
maskedImage(binaryImage) = grayImage(binaryImage);% Demo by ImageAnalyst
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 = 14;% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');baseFileName = 'coins.png';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);% Check if file exists.
if ~exist(fullFileName, 'file') % File doesn't exist -- didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, '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; endendgrayImage = imread(fullFileName);% Get the dimensions of the image.
% numberOfColorBands should be = 1.
[rows columns numberOfColorBands] = size(grayImage);% Display the original gray scale image.
subplot(2, 2, 1);imshow(grayImage, []);title('Original Grayscale Image', 'FontSize', fontSize);% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off') % Let's compute and display the histogram.
[pixelCount grayLevels] = imhist(grayImage);subplot(2, 2, 2); bar(pixelCount);grid on;title('Histogram of original image', 'FontSize', fontSize);xlim([0 grayLevels(end)]); % Scale x axis manually.
yl = ylim();line([150 150], [0 yl(2)], 'Color', 'r');% Threshold at 150
binaryImage = grayImage > 150;% Display the original gray scale image.subplot(2, 2, 3);imshow(binaryImage, []);title('Binary Image', 'FontSize', fontSize);% Mask the image
maskedImage = zeros(size(grayImage)); % Initialize.% Assign values from grayImage that are > 150.
maskedImage(binaryImage) = grayImage(binaryImage);% Display the original gray scale image.subplot(2, 2, 4);imshow(maskedImage, []);title('Masked Image', 'FontSize', fontSize);% Code to have user draw line across a binary image and
% find intersection points.
% Take out the next two lines if you're transferring this to your program.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables.
clc; % Clear the command window.
workspace; % Make sure the workspace panel is showing.
format longg;format compact;fontSize = 20;% Check that user has the Image Processing Toolbox installed.
hasIPT = license('test', 'image_toolbox');if ~hasIPT % User does not have the toolbox installed.
message = sprintf('Sorry, but you do not seem to have the Image Processing Toolbox.\nDo you want to try to continue anyway?'); reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes'); if strcmpi(reply, 'No') % User said No, so exit.
return; endendgrayImage = uint8(mat2gray(peaks(400)));% Get the dimensions of the image.
% numberOfColorBands should be = 1.
[rows columns numberOfColorBands] = size(grayImage);% Display the original gray scale image.
subplot(2, 1, 1);imshow(grayImage, []);axis on;title('Original Grayscale Image', 'FontSize', fontSize);% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off') % Initialize
button = 1;while button ~= 2 % Get which action the user wants to do.
button = menu('Choose an action', 'Find Intersection', 'Exit'); if button == 2 % Bail out because they clicked Exit.
break; end % Make caption the instructions.
subplot(2, 1, 1); cla reset; imshow(grayImage, []); axis on; title('Left-click first point. Right click last point.', 'FontSize', fontSize); % Ask user to plot a line.
[x, y, profile] = improfile(); % Plot line.
hold on; plot(x, y, 'r-', 'LineWidth', 2); % Restore caption.
title('Binary Image', 'FontSize', fontSize); % Calculate distance
distanceInPixels = sqrt((x(1)-x(end))^2 + (y(1)-y(end))^2); % Plot it.
subplot(2,1,2); plot(profile, 'LineWidth', 2); grid on; % Initialize caption = sprintf('Intensity Profile Along Line\nThe distance = %f pixels', ... distanceInPixels); title(caption, 'FontSize', fontSize); ylabel('Gray Level', 'FontSize', fontSize); xlabel('Pixels Along Line', 'FontSize', fontSize); ylim([0 1.5]); % Find intersection points.
dif = diff(profile); % Find where it goes from 0 to 1, and dif == 1;
nonZeroElements = find(dif > 0); % Plot them
subplot(2, 1, 1); % Go back to the image.
hold on; plot(x(nonZeroElements), y(nonZeroElements),... 'ro', 'MarkerSize', 10); % Find where it goes from 1 to 0, and dif == -1;
nonZeroElements2 = find(dif < 0); % Plot them subplot(2, 1, 1); % Go back to the image. hold on; plot(x(nonZeroElements2), y(nonZeroElements2),... 'ro', 'MarkerSize', 10);end
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