How to remove unwanted small blob?

First of all, don't use watershed or whatever to break up the blobs into sub-blobs. Then use imclearborder() to get rid of blobs touching the borders, then use bwareafilt(binaryImage, 1) to get just the largest blob.

9 个评论
显示 7更早的评论隐藏 7更早的评论

Tan Wen Kun 2015-11-12

编辑：Walter Roberson 2015-11-12

在 MATLAB Online 中打开

IM = edge(im2double(rgb2gray(imread('jump.jpg'))),'canny');
figure;imshow(IM,[]);
% load IM
[r c] = size(IM);
data = IM(:);
[center,U,obj_fcn] = fcm(data,4); % Fuzzy C-means classification with 4 classes    
% Finding the pixels for each class
maxU = max(U);
index1 = find(U(1,:) == maxU);
index2 = find(U(2,:) == maxU);
index3 = find(U(3,:) == maxU);
index4 = find(U(4,:) == maxU);
% Assigning pixel to each class by giving them a specific value
fcmImage(1:length(data))=0;       
fcmImage(index1)= 1;
fcmImage(index2)= 0.66;
fcmImage(index3)= 0.33;
fcmImage(index4)= 0.0;
% Reshapeing the array to a image
imagNew = reshape(fcmImage,r,c);
figure;imshow(imagNew,[]);
gradmag = imagNew;
g = gradmag - min(gradmag(:));
g = g / max(g(:));
th = graythresh(g); %# Otsu's method.
a = imhmax(g,th/2); %# Conservatively remove local maxima.
th = graythresh(a);
b = a > th/4; %# Conservative global threshold.
c = imclose(b,ones(8)); %# Try to close contours.
d = imfill(c,'holes'); %# Not a bad segmentation by itself.
%# Use the rough segmentation to define markers.
%#g2 = imimposemin(g, ~ imdilate( bwperim(a), ones(4) ));
%#L = watershed(g2);
%#Lrgb = label2rgb(L);
%#figure;imshow(g2,[]);
g3 = imclearborder(d);
g4 = bwareafilt(g3,1);

Tan Wen Kun 2015-11-13

c.jpg
d.jpg

binary is c and d, b is edge image

Image Analyst 2015-11-13

在 MATLAB Online 中打开

Try this:

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 = 20;
fullFileName = fullfile(pwd, 'd.jpg');
grayImage = imread(fullFileName);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[rows, columns, numberOfColorBands] = size(grayImage);
if numberOfColorBands > 1
  % It's not really gray scale like we expected - it's color.
  % Convert it to gray scale by taking only the green channel.
  grayImage = grayImage(:, :, 2); % Take green channel.
end
% Display the original gray scale image.
subplot(2, 2, 1);
imshow(grayImage, []);
title('Original Grayscale Image', 'FontSize', fontSize, 'Interpreter', 'None');
% 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') 
% Binarize the gray scale image.
binaryImage = grayImage > 128;
subplot(2, 2, 2);
imshow(binaryImage, []);
title('Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Get rid of blobs touching the border
binaryImage = imclearborder(binaryImage);
subplot(2, 2, 3);
imshow(binaryImage, []);
title('With border cleared', 'FontSize', fontSize, 'Interpreter', 'None');
% Get the largest remaining blob:
binaryImage = bwareafilt(binaryImage, 1);
subplot(2, 2, 4);
imshow(binaryImage, []);
title('Largest Remaining Blob', 'FontSize', fontSize, 'Interpreter', 'None');

请先登录，再进行评论。

How to remove unwanted small blob?

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

采纳的回答

9 个评论
显示 7更早的评论隐藏 7更早的评论

更多回答（0 个）

另请参阅

类别

标签

产品

Community Treasure Hunt

How to remove unwanted small blob?

1 个评论 显示 -1更早的评论隐藏 -1更早的评论

采纳的回答

9 个评论 显示 7更早的评论隐藏 7更早的评论

更多回答（0 个）

另请参阅

类别

标签

产品

Community Treasure Hunt

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

9 个评论
显示 7更早的评论隐藏 7更早的评论