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curve fitting and image segmentation

조회 수: 39(최근 30일)
Apoorva Maiya
Apoorva Maiya 2020년 3월 29일
댓글: Cansu Kelebek 2021년 9월 19일 8:29
Hi all, I have a grayscale image-'FLIR0888.jpg' (attatched within) I have segmented this image into right and left breasts by fitting a polynomial curve and finding the intersection point of the two fitted curves. Now, below is the image of right breast and the curve fitted is shown in blue. How do i segment the grayscale image along this blue curve? I want the part of the image below this blue curve to be gone. How do I approach this? I have attatched the code and the original image below, thanks in advance.
clc;
clear;
close all;
a=rgb2gray(imread('FLIR0888.jpg'));
ed=edge(a,'canny',0.2,0.5);
bw1=bwareaopen(ed,10);
bw=imdilate(bw1,true(3));
se = strel('disk',4);
I=imclose(bw,se);
BW=imclearborder(I);
[B,L]= bwboundaries(BW,'noholes');
[~,I] = sort(cellfun(@length,B),'descend');
BB= B(I);
x1 = BB{1}(:, 2);y1 = BB{1}(:, 1);
x2 = BB{2}(:, 2);y2 = BB{2}(:, 1);
P1=polyfit(y1,x1,3);
P2=polyfit(y2,x2,3);
yy = linspace( 1, size(L,1));
p1=polyval( P1, yy );
p2=polyval( P2, yy);
x_intersect = fzero(@(x) polyval(P1-P2,x),3);
y_intersect = polyval(P1,x_intersect);
segimgR=a(:,1:y_intersect);
[m,n]=size(segimgR);
segimgl=a(:,y_intersect:end);
segimgL=imresize(segimgl,[m,n]);
figure()
subplot(2,2,1);imshow(a);title('original image');
subplot(2,2,2);imshow(a, 'border', 'tight' );
hold on
plot(p1,yy);
plot(p2,yy);
hold off
subplot(2,2,3);imshow(segimgR);
subplot(2,2,4);imshow(segimgL);
figure()
subplot(1,2,1);imshow(segimgR);
hold on
plot(p1,yy);
hold off

채택된 답변

Thiago Henrique Gomes Lobato
Thiago Henrique Gomes Lobato 2020년 3월 29일
In this case, for each column you have there's a different line point, so you have to check for each one individually and do the threshold accordingly. Here is a implementation that does this, if you ever want another direction it is equivalent:
% Loop for all pixels in one direction
MaskUP = zeros(size(L));
AllDirectionIndex = 1:size(L,2);
DivisionPoints=polyval( P1, 1:size(L,1) );
for idx=1:size(L,1)
AboveIndex = AllDirectionIndex<DivisionPoints(idx);
MaskUP(idx,AboveIndex) = 1;
end
figure,imshow( uint8(MaskUP.*double(a) ))
  댓글 수: 2
Cansu Kelebek
Cansu Kelebek 2021년 9월 18일 14:19
Hi, Could you please help me to separate the left and right half of breast? There is code below which I tried to seperate both left and right of breast. @Apoorva Maiya@Thiago Henrique Gomes Lobato
clc; clear; close all;
a=rgb2gray(imread('DINAMIC-FRONTAL1.jpg'));
en= imsharpen(a,'Radius',2,'Amount',1);
B = imgaussfilt(en,1.4);
ed=edge(B,'canny',0.3,0.5);
figure();imshow(ed);title('canny edge');
bw1=bwareaopen(ed,10);
se = strel('disk',4);
bw=imdilate(bw1,se);
figure();imshow(bw);
[y x] = find( bw );
right = find(min(a));
as=findpeaks(y);
xr = x(right);
yr = y(right);
xl = x(as);
yl = y(as);
pr = polyfit( yr, xr, 2); %// fit 2rd deg poly
pl = polyfit( yl, xl, 2 );
yy = linspace( 1, size(bw,1), 50 );
figure; imshow(a, 'border', 'tight' );
hold all
plot( polyval( pr, yy ), yy, '.-', 'LineWidth', 1 );
plot( polyval( pl, yy ), yy, '.-', 'LineWidth', 1 );

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추가 답변(1개)

Image Analyst
Image Analyst 2021년 9월 18일 15:06
@Cansu Kelebek, try this to find the dividing line between the 2 breasts:
% Demo by Image Analyst
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 short g;
format compact;
fontSize = 20;
grayImage = rgb2gray(imread('DINAMIC-FRONTAL.jpeg'));
en= imsharpen(grayImage,'Radius',2,'Amount',1);
B = imgaussfilt(en,1.4);
ed=edge(B,'canny',0.3,0.5);
subplot(2, 2, 1);
imshow(ed);
title('Initial Canny Edge', 'FontSize', fontSize);
bw1=bwareaopen(ed,10);
se = strel('disk', 4);
bw=imdilate(bw1,se);
subplot(2, 2, 2);
imshow(bw);
title('Canny Edge Dilated', 'FontSize', fontSize);
% Non-working code from poster commented out.
% [y x] = find( bw );
% right = find(min(a));
% as=findpeaks(y);
% xr = x(right);
% yr = y(right);
% xl = x(as);
% yl = y(as);
% pr = polyfit( yr, xr, 2); %// fit 2rd deg poly
% pl = polyfit( yl, xl, 2 );
% yy = linspace( 1, size(bw,1), 50 );
% subplot(2, 2, 3);
% imshow(a, 'border', 'tight' );
% hold all
% plot( polyval( pr, yy ), yy, '.-', 'LineWidth', 1 );
% plot( polyval( pl, yy ), yy, '.-', 'LineWidth', 1 );
% Take the 2 largest blobs.
bw = bwareafilt(bw, 2);
subplot(2, 2, 3);
imshow(bw);
title('2 Largest Blobs', 'FontSize', fontSize);
% Find the bounding boxes
props = regionprops(bw, 'BoundingBox');
bb = vertcat(props.BoundingBox);
xLeft = bb(:, 1);
widths = bb(:, 3);
% Find the right edge of the left blob.
x1 = xLeft(1) + widths(1);
% Find the midpoint between the left edge of the right blob and the right edge of the left blob.
xMiddle = (x1 + xLeft(2)) / 2;
% Put a red line between them
xline(xMiddle, 'Color', 'r', 'LineWidth', 3);
subplot(2, 2, 4);
imshow(grayImage);
title('2 Largest Blobs', 'FontSize', fontSize);
% Put a red line between them
xline(xMiddle, 'Color', 'r', 'LineWidth', 3);
title('Original with Dividing Line', 'FontSize', fontSize);
  댓글 수: 11
Cansu Kelebek
Cansu Kelebek 2021년 9월 19일 8:29
Nope it’s just a small part of my thesis. But I couldn’t pass this part.

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