如何使用最佳擬合點直線穿過條形碼的質心點Matlab

set(0,'DefaultFigureWindowStyle','docked'); 
close all;clear all;clc; 
Im = imread('29ekeap.jpg'); 
Im=rgb2gray(Im); 
%% 

%Make binary 
temp = zeros(size(Im)); 
temp(Im > mean(Im(:)))=1; 
Im = temp; 

%Visualize 
f1 = figure(1); 
imagesc(Im);colormap(gray); 

%Find connected components 
LabelIm = bwlabel(Im); 

RegionInfo = regionprops(LabelIm); 

%Remove background region 
RegionInfo(1) = []; 

%Get average area of regions 
AvgArea = mean([RegionInfo(1:end).Area]); 

%Vector to keep track of likely "bar elements" 
Bar = zeros(length(RegionInfo),1); 

%Iterate over regions, plot centroids if area is big enough 
for i=1:length(RegionInfo) 
    if RegionInfo(i).Area > AvgArea 
     hold on; 
     plot(RegionInfo(i).Centroid(1),RegionInfo(i).Centroid(2),'r*') 
     Bar(i) = 1; 
    end 
end 

%Extract x,y points for interpolation 
X = [RegionInfo(Bar==1).Centroid]; 
X = reshape(X,2,length(X)/2); 

x = X(1,:); 
y = X(2,:); 

%Plot line according to Andrey 
p = polyfit(x,y,1); 
xMin = min(x(:)); 
xMax = max(x(:)); 
xRange = xMin:0.01:xMax; 
yRange = p(1).*xRange + p(2); 
plot(xRange,yRange,'LineWidth',2,'Color',[0.9 0.2 0.2]);

結果是一個不錯的擬合線。你應該能夠通過使用'p'polynomal來擴展它的結尾，並且在你不需要再遇到'1'時進行評估。

結果：

enter image description here

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2012-01-18 18:34:59 Vidar

如果你已經找到了x，y的中心，你應該使用polyfit函數：然後，你會找到最佳線的多項式係數。爲了繪製段，你可以採取的最小和最大X

p = polyfit(x,y,1); 
xMin = min(x(:)); 
xMax = max(x(:)); 
xRange = xMin:0.01:xMax; 
yRange = p(1).*xRange + p(2); 
plot(xRange,yRange);

來源

2012-01-18 11:04:41

如果你的最終目標是產生垂直於條碼的條和大致經過酒吧的重心線，然後我有另一個選項，供您考慮...

一個簡單的解決方案是執行霍夫變換來檢測條碼中行的主要方向。一旦找到條形碼中的線條角度，您只需旋轉90度即可得到垂直線的斜率。然後條碼的質心可以用作這條線的截距。使用功能HOUGH，並從Image Processing Toolbox HOUGHPEAKS，這裏是從第1步開始你的影像裁剪後的版本代碼：

img = imread('bar_code.jpg'); %# Load the image 
img = im2bw(img);    %# Convert from RGB to BW 

[H, theta, rho] = hough(img); %# Perform the Hough transform 
peak = houghpeaks(H);   %# Find the peak pt in the Hough transform 
barAngle = theta(peak(2));  %# Find the angle of the bars 
slope = -tan(pi*(barAngle + 90)/180); %# Compute the perpendicular line slope 

[y, x] = find(img); %# Find the coordinates of all the white image points 
xMean = mean(x);  %# Find the x centroid of the bar code 
yMean = mean(y);  %# Find the y centroid of the bar code 

xLine = 1:size(img,2);     %# X points of perpendicular line 
yLine = slope.*(xLine - xMean) + yMean; %# Y points of perpendicular line 

imshow(img);    %# Plot bar code image 
hold on;     %# Add to the plot 
plot(xMean, yMean, 'r*'); %# Plot the bar code centroid 
plot(xLine, yLine, 'r'); %# Plot the perpendicular line

而這裏的結果圖像：

enter image description here

來源

2012-01-18 21:13:48 gnovice

如何使用最佳擬合點直線穿過條形碼的質心點Matlab

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