MATLAB: Image processing using Matlab

digital image processingfilterimage analysisimage processingImage Processing Toolboximage segmentationsmoothing

I have the following result of segmentation

How can I improve the results?

1) I want to improve the appearance to get the vessels more smooth.

2) I want to extract the oval-like part of the vessels in the middle of the image.

Any suggestions?

*****************

Here is a link to the image

https://copy.com/GT6n8EF82BKw

Best Answer

For your first question:

Is this strictly for appearances? If so, does medfilt2 do what you want?

 rawImg = rgb2gray(imread('seg_vessel.jpg'));
 nbhd = [2 2]; %play around with neighborhood size to get the smoothness you want
 smoothedImg = medfilt2(rawImg,nbhd);
 figure;imagesc(rawImg); colormap(gray)
 figure;imagesc(smoothedImg); colormap(gray)

Related Solutions

MATLAB: Why imfill resul is a white figure

Your image had a white frame/border around it. Use imclearborder() to get rid of that. See corrected code:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
rgbImage = imread('hole.png');
subplot(2,2,1)
imshow(rgbImage)
title('Original Image', 'FontSize', fontSize);
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
% 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') 
%binarization
binaryImage = im2bw(rgbImage);
% Display this image.

subplot(2,2,2);
imshow(binaryImage);
title('Original Binary Image', 'FontSize', fontSize);
% Important: Get rid of surrounding white border (frame):
binaryImage = imclearborder(binaryImage);
% Display this image.
subplot(2,2,3);
imshow(binaryImage);
title('Frame now removed', 'FontSize', fontSize);
%  Close the holes
filledImage = imfill(binaryImage, 'holes');
subplot(2,2,4);
imshow(filledImage);
title('Image without frame or holes', 'FontSize', fontSize);

MATLAB: Crop dark area and display the face only

Convert to grayscale and then threshold and find the bounding box

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. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
% Read in the color image.
folder = pwd;
baseFileName = 'm2.bmp';
% 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
rgbImage = imread(fullFileName);
% Get the dimensions of the image.  numberOfColorBands should be = 3.
[rows, columns, numberOfColorBands] = size(rgbImage);
% Display the original color image.
subplot(2, 3, 1);
imshow(rgbImage, []);
axis on;
title('Original Color Image', 'FontSize', fontSize);
drawnow;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Histogram the red channel, but there is a huge spike at 255 so let's not count those.
subplot(2, 3, 2);
grayImage = rgb2gray(rgbImage);
imshow(grayImage, []);
title('Gray Scale version', 'FontSize', fontSize);
subplot(2, 3, 3);
histogram(grayImage(grayImage<255))
grid on;
title('Histogram of Gray Scale Image', 'FontSize', fontSize);
someThresholdValue = 150;
binaryImage = grayImage > someThresholdValue;
% Take largest blob
binaryImage = bwareafilt(binaryImage, 1);
subplot(2, 3, 4);
imshow(binaryImage);
grid on;
title('Binary Image', 'FontSize', fontSize);
% Label the binary image.
labeledImage = bwlabel(binaryImage);
props = regionprops(labeledImage, 'BoundingBox');
bbox = props.BoundingBox
croppedImageRGB = imcrop(rgbImage, bbox);
subplot(2, 3, 5);
imshow(croppedImageRGB);
grid on;
title('Cropped RGB Image', 'FontSize', fontSize);
% Gray scale version of cropped image
croppedImageGray = imcrop(grayImage, bbox);
subplot(2, 3, 6);
imshow(croppedImageGray);
grid on;
title('Cropped Gray Scale Image', 'FontSize', fontSize);

Best Answer

Related Solutions

MATLAB: Why imfill resul is a white figure

MATLAB: Crop dark area and display the face only

Related Question