MATLAB Answers

Why can't a circle be detected in such an obvious image?

조회 수: 2(최근 30일)
cui 2021년 5월 20일
답변: Image Analyst 2021년 5월 21일
Why can't a circle be detected in such an obvious image?
img = imread('circle.png');
[centers1,radii1] = imfindcircles(img,100,...
No matter how you adjust the value of 'sensitivity' or the radius or 'ObjectPolarity', the circle is not detected, why?
os: win10
matlab R2021a

채택된 답변

Image Analyst
Image Analyst 2021년 5월 21일
Try increasing the sensitivity to 0.95
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;
folder = pwd;
baseFileName = 'circle1.png';
grayImage = imread(baseFileName);
% 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(grayImage)
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 = min(grayImage, [], 3);
% Display the image.
imshow(grayImage, []);
axis('on', 'image');
title('Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
hFig = gcf;
hFig.WindowState = 'maximized'; % May not work in earlier versions of MATLAB.
[centers1, radii1] = imfindcircles(grayImage,[75, 125],'Sensitivity',0.95,'ObjectPolarity','bright')
viscircles(centers1, radii1, 'LineWidth', 4);

추가 답변(1개)

Stephan 2021년 5월 20일
편집: Stephan 2021년 5월 20일
Use a range for radius input argument such as:
[centers1,radii1] = imfindcircles(img,[50 200],'Sensitivity',0.85,'ObjectPolarity','bright')
  댓글 수: 1
cui 2021년 5월 21일
Hi, your solution is not working and still not detecting any results!
you can try code

댓글을 달려면 로그인하십시오.

Community Treasure Hunt

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

Start Hunting!

Translated by