# Detect the shape in MATLAB

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Med Future on 15 Mar 2022
Commented: Image Analyst on 25 Mar 2022
Hello, I hope you are doing well.
I have the image of 1000x1000.I have attached the image below I want to detect the number of lines in the image and pixel value of each line. How can i do it in MATLAB
as you can see in image, there is four lines, is Hough transform work on this or any image processing.
For example line is at 720, then it show pixel value 720
##### 2 CommentsShowHide 1 older comment
Med Future on 16 Mar 2022
Yes line are Parallel. Then how can i detect?

Image Analyst on 15 Mar 2022
% Make the image binary, if it's not already.
binaryImage = grayImage > 128;
% Count the lines.
[LabeledImage, numLines] = bwlabel(binaryImage);
Image Analyst on 25 Mar 2022
I've given it to you both ways. First I found line segments, with the starting and ending points, then you said you wanted "only unique lines" so if two blobs were on the same line/row, I used unique() to get only unique lines. So if two blobs were on the same row, I'd draw only one line across the whole row. So now you have it both ways. Does that not solve the problem?

### More Answers (1)

yanqi liu on 16 Mar 2022
bw = im2bw(img);
% 霍夫分析
[H,T,R] = hough(bw);
P = houghpeaks(H,5,'threshold',ceil(0.3*max(H(:))));
lines = houghlines(bw,T,R,P,'FillGap',5,'MinLength',7);
max_len = 0;
line_r = [];
figure; imshow(img, []); hold on;
for k = 1:length(lines)
xy = [lines(k).point1; lines(k).point2];
plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','cyan');
p = [];
xy = round(xy);
for j = min(xy(:,1)) : max(xy(:,1))
p = [p img(xy(1,2), j)];
end
text(xy(1,1),xy(1,2)-15, sprintf('pixel value = %.2f', mean(p)), 'color', 'r');
end
Image Analyst on 19 Mar 2022
Sorry - I put it in the wrong place. it was meant to be a reply to your comment to me

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