MATLAB: How to detect edge/contour of threshold image

edge detectionimage segmentationultrasound image

I am working with ultrasound image. I had threshold the US image.Now i want to get the edge of the thresholded image.

Best Answer

https://www.mathworks.com/help/images/ref/bwboundaries.html

If you don't have the image processing toolbox, things get much more difficult.

Related Solutions

MATLAB: Threshold

See my demo (simply copy and paste):

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures.
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;
% Change the current folder to the folder of this m-file.
if(~isdeployed)
  cd(fileparts(which(mfilename)));
end
  
% 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;
  end
end
% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'cell.tif';
fullFileName = fullfile(folder, baseFileName);
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
if ~exist(fullFileName, 'file')
  % 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.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end
grayImage = 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, 'Position', get(0,'Screensize')); 
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off') 
% Threshold the image.
binaryImage = grayImage >= 70 & grayImage <= 130;
% Display the binary image.
subplot(2, 2, 2);
imshow(binaryImage, []);
title('Binary Image', 'FontSize', fontSize);
% Mask the image.
maskedImage = grayImage; % Initialize.
maskedImage(~binaryImage) = 0;
% Display the masked image.
subplot(2, 2, 3);
imshow(maskedImage, []);
title('Masked Image', 'FontSize', fontSize);
msgbox('Done with demo!');

MATLAB: How can i use color image segmentation using threshold base edge detection improving through weiner filter and hormonic filter

Hi Muhammad,

Without knowing the exact problem you're facing, here are some general resources to help you get started.

Wiener Filtering of images: https://www.mathworks.com/help/images/ref/wiener2.html
Edge detection in MATLAB: https://www.mathworks.com/discovery/edge-detection.html
Image filtering in MATLAB: https://www.mathworks.com/help/images/linear-filtering.html

- Sebastian

Best Answer

Related Solutions

MATLAB: Threshold

MATLAB: How can i use color image segmentation using threshold base edge detection improving through weiner filter and hormonic filter

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