How to remove TEXT from an ECG image?

조회 수: 5 (최근 30일)
Sam Rosh
Sam Rosh 2018년 12월 12일
댓글: Image Analyst 2018년 12월 19일
I have an ECG image as attached. Kindly help me to remove the TEXT regions{I, II, III, avR,aVL...V1 to V5 etc}. Only after removing these regions I an go further in my research study. Please help me to solve this. I use matlab 2012.

채택된 답변

Image Analyst
Image Analyst 2018년 12월 13일
편집: Image Analyst 2018년 12월 13일
Easy. Simply create a mask that is true where there are letters, and use it to erase where the mask is.
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 = 18;
folder = pwd; % Current folder.
baseFileName = 'ecg.jpg';
% % Have user browse for a file, from a specified "starting folder."
% % For convenience in browsing, set a starting folder from which to browse.
% startingFolder = pwd; % or 'C:\wherever';
% if ~exist(startingFolder, 'dir')
% % If that folder doesn't exist, just start in the current folder.
% startingFolder = pwd;
% end
% % Get the name of the file that the user wants to use.
% defaultFileName = fullfile(startingFolder, '01.png');
% [baseFileName, folder] = uigetfile(defaultFileName, 'Select a file');
% if baseFileName == 0
% % User clicked the Cancel button.
% return;
% end
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
rgbImage = 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(rgbImage)
if numberOfColorChannels > 1
% It's not really gray scale like we expected - it's color.
% Use weighted sum of ALL channels to create a gray scale image.
% grayImage = rgb2gray(rgbImage);
% ALTERNATE METHOD: Convert it to gray scale by taking only the green channel,
% which in a typical snapshot will be the least noisy channel.
grayImage = rgbImage(:, :, 2); % Take green channel.
else
grayImage = rgbImage; % It's already gray scale.
end
% Now it's gray scale with range of 0 to 255.
% Display the image.
subplot(2, 2, 1);
imshow(grayImage, []);
title('Original Image', 'FontSize', fontSize, 'Interpreter', 'None');
axis('on', 'image');
hp = impixelinfo();
%------------------------------------------------------------------------------
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0, 0.04, 1, 0.96]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
drawnow;
% Display the histogram.
subplot(2, 2, 2);
histogram(grayImage, 256);
title('Histogram of image', 'FontSize', fontSize, 'Interpreter', 'None');
grid on;
drawnow;
% Crop out black rectangle inside the white frame.
croppedImage = grayImage(33:622, 142:1392);
% Update sizes.
[rows, columns, numberOfColorChannels] = size(croppedImage)
% Read in mask
lettersMask = imread('mask.png');
% Resize it if necessary.
if ~isequal(size(croppedImage), size(lettersMask))
size(croppedImage) % Display in command window, ofr our information
size(lettersMask)
imresize(lettersMask, size(croppedImage));
end
% Display the mask.
subplot(2, 2, 2);
imshow(lettersMask);
hp = impixelinfo();
axis('on', 'image'); % Make sure image is not artificially stretched because of screen's aspect ratio.
title('Stored mask recalled from disk', 'FontSize', fontSize);
% Mask image
maskedImage = croppedImage; % Initialize
maskedImage(lettersMask) = 0; % Erase where the letters are.
% Display the mask.
subplot(2, 2, 3:4);
imshow(maskedImage, []);
hp = impixelinfo();
axis('on', 'image'); % Make sure image is not artificially stretched because of screen's aspect ratio.
title('Final cropped and masked image', 'FontSize', fontSize);
msgbox('Done!');
You will be left with an image that is essentially no good to analyze. You really need to get the actual signals and not try to do signal analysis from a heavily quantized, low resolution image like this.
  댓글 수: 8
Sam Rosh
Sam Rosh 2018년 12월 19일
I am using matlab 2012 b. {sorry to get latest version ,I dont have fund} so bwareafilt function is not available. can I use any other similar function which is available in 2012b or 2013a. Many thanks for providing a path.
Image Analyst
Image Analyst 2018년 12월 19일
You can use bwareaopen().

댓글을 달려면 로그인하십시오.

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Image Processing Toolbox에 대해 자세히 알아보기

제품


릴리스

R2012b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by