can someone help me edit the code below so that the output image can display the value of rotation angle of the object with axis guide

Question

Nurul Farhana Mohd Fadzli 2022-5-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1722655-can-someone-help-me-edit-the-code-below-so-that-the-output-image-can-display-the-value-of-rotation-a

评论： DGM 2023-1-6

采纳的回答： Image Analyst

在 MATLAB Online 中打开

It is just the example image that i want, the axis with the angle:

this is my input image:

% Perform edge detection with interpolation during non maximum suppression
function CannyEdgeDetector()
    close all;  % Close figures
    saveImage = true;
    sigma = 1; % Gaussian filter sigma
    highThresholdRatio = 0.275; % High threshold ratio
    lowThresholdRatio = 0.25; % Low threshold ratio OF THE high threshold
    
    % Change the current folder to the folder of this m-file.
    % Courtesy of Brett Shoelson
    if(~isdeployed)
      cd(fileparts(which(mfilename)));
    end
    
    im = imread('C:\Users\User\Pictures\bt.jpeg');
    figure; imshow(im);
    title('Original Image');
    %if saveImage
        %imwrite(im, 'C:\Users\User\Pictures\O3.jpeg');
    %end
    
    % Smooth with Gaussian 5x5 filter to reduce noise
    im = rgb2gray(im);
    figure; imshow(im);
    title('B/W Image');
    %if saveImage
        %imwrite(im, 'Output_Photos\2_bw.jpg');
    %end
    
    im = double(imgaussfilt(im,sigma));
    figure; imshow(NormalizeMatrix(im));
    title('Gaussian Filter');
    %if saveImage
        %imwrite(NormalizeMatrix(im), 'Output_Photos\3_gaussian.jpg');
    %end
    
    % Find the intensity gradient of the image
    Gx = SobelFilter(im, 'x');
    Gy = SobelFilter(im, 'y');
    Gx = imgaussfilt(Gx,sigma);
    Gy = imgaussfilt(Gy,sigma);
    figure; imshow(abs(normalize(Gx)));
    title('Gx Sobel Filter');
    %if saveImage
        %imwrite(abs(NormalizeMatrix(Gx)), 'Output_Photos\4_gx_sobel.jpg');
    %end
    figure; imshow(abs(NormalizeMatrix(Gy)));
    title('Gy Sobel Filter');
    %if saveImage
        %imwrite(abs(NormalizeMatrix(Gy)), 'Output_Photos\5_gy_sobel.jpg');
    %end
    
    % Find the magnitude of the gradient
    Gmag = sqrt(Gx.^2 + Gy.^2);
    angle = atan2(Gy,Gx)*180/pi;
    figure; imshow(NormalizeMatrix(Gmag));
    title('Gmag');
    %if saveImage
        %imwrite(NormalizeMatrix(Gmag), 'Output_Photos\6_gmag.jpg');
    %end
         
    % Perform non-maximum suppression using interpolation
    [h,w] = size(im);
    X=[-1,0,+1 ;-1,0,+1 ;-1,0,+1];
	Y=[-1,-1,-1 ;0,0,0 ;+1,+1,+1];
    output = zeros(h,w);
    x = [0 1];
    for i=2:h-1 % row
        for j=2:w-1 % col
            if (angle(i,j)>=0 && angle(i,j)<=45) || ...
                    (angle(i,j)<-135 && angle(i,j)>=-180)
                yBot = [Gmag(i,j+1) Gmag(i+1,j+1)];
                yTop = [Gmag(i,j-1) Gmag(i-1,j-1)];
                x_est = abs(Gy(i,j)/Gmag(i,j)); % y
                if (Gmag(i,j) >= ((yBot(2)-yBot(1))*x_est+yBot(1)) && ...
                    Gmag(i,j) >= ((yTop(2)-yTop(1))*x_est+yTop(1))) % interpolation
                    output(i,j)= Gmag(i,j);
                else
                    output(i,j)=0;
                end
            elseif (angle(i,j)>45 && angle(i,j)<=90) || ...
                    (angle(i,j)<-90 && angle(i,j)>=-135)
                yBot = [Gmag(i+1,j) Gmag(i+1,j+1)];
                yTop = [Gmag(i-1,j) Gmag(i-1,j-1)];
                x_est = abs(Gx(i,j)/Gmag(i,j));
                if (Gmag(i,j) >= ((yBot(2)-yBot(1))*x_est+yBot(1)) && ...
                    Gmag(i,j) >= ((yTop(2)-yTop(1))*x_est+yTop(1)))
                    output(i,j)= Gmag(i,j);
                else
                    output(i,j)=0;
                end
            elseif (angle(i,j)>90 && angle(i,j)<=135) || ...
                    (angle(i,j)<-45 && angle(i,j)>=-90)
                yBot = [Gmag(i+1,j) Gmag(i+1,j-1)];
                yTop = [Gmag(i-1,j) Gmag(i-1,j+1)];
                x_est = abs(Gx(i,j)/Gmag(i,j));
                if (Gmag(i,j) >= ((yBot(2)-yBot(1))*x_est+yBot(1)) && ...
                    Gmag(i,j) >= ((yTop(2)-yTop(1))*x_est+yTop(1)))
                    output(i,j)= Gmag(i,j);
                else
                    output(i,j)=0;
                end
            elseif (angle(i,j)>135 && angle(i,j)<=180) || ...
                    (angle(i,j)<0 && angle(i,j)>=-45)
                yBot = [Gmag(i,j-1) Gmag(i+1,j-1)];
                yTop = [Gmag(i,j+1) Gmag(i-1,j+1)];
                x_est = abs(Gx(i,j)/Gmag(i,j));
                if (Gmag(i,j) >= ((yBot(2)-yBot(1))*x_est+yBot(1)) && ...
                    Gmag(i,j) >= ((yTop(2)-yTop(1))*x_est+yTop(1)))
                    output(i,j)= Gmag(i,j);
                else
                    output(i,j)=0;
                end
            end           
        end
    end
    
    Gmag = NormalizeMatrix(output);
    figure; imshow(Gmag);
    title('Non Maximum Suppression');
    %if saveImage
        %imwrite(Gmag, 'Output_Photos\7_non_maximum_suppression.jpg');
    %end
    
    % Perform double thresholding
    highThreshold = max(max(Gmag))*highThresholdRatio;
    lowThreshold = highThreshold*lowThresholdRatio;
    strongEdgesRow = zeros(1,h*w); % Keep track of the strong edge row index
    strongEdgesCol = zeros(1,h*w); % Keep track of the strong edge col index
    weakEdgesRow = zeros(1,h*w);  % Keep track of the weak edge row index
    weakEdgesCol = zeros(1,h*w);  % Keep track of the weak edge col index
    strongIndex = 1;
    weakIndex = 1;
    for i=2:h-1 % row
        for j=2:w-1 % col
            if Gmag(i,j) > highThreshold    % Strong edge
                Gmag(i,j) = 1;
                strongEdgesRow(strongIndex) = i;
                strongEdgesCol(strongIndex) = j;
                strongIndex = strongIndex + 1;
            elseif Gmag(i,j) < lowThreshold % No edge
                Gmag(i,j) = 0;
            else                            % Weak edge
                weakEdgesRow(weakIndex) = i;
                weakEdgesCol(weakIndex) = j;
                weakIndex = weakIndex + 1;
            end
        end
    end
    figure; imshow(Gmag);
    title('Double Threshold'); 
    %if saveImage
        %imwrite(Gmag, 'Output_Photos\8_double_threshold.jpg');
    %end
    
    % Perform edge tracking by hysteresis
    set(0,'RecursionLimit',10000)
    for i=1:strongIndex-1
        % Find the weak edges that are connected to strong edges and set 
        % them to 1
        Gmag = FindConnectedWeakEdges(Gmag, strongEdgesRow(i),...
            strongEdgesCol(i));
    end
    figure; imshow(Gmag);
    title('Edge Tracking Before Clean Up'); 
    %if saveImage
        %imwrite(Gmag, 'Output_Photos\9_edge_tracking.jpg');
    %end
    
    % Remove the remaining weak edges that are not actually edges
    % and is noise instead
    for i=1:weakIndex-1
        if Gmag(weakEdgesRow(i),weakEdgesCol(i)) ~= 1
            Gmag(weakEdgesRow(i),weakEdgesCol(i)) = 0;
        end
    end
    figure; imshow(Gmag);
    title('Edge Tracking After Clean Up'); 
    %if saveImage
        %imwrite(Gmag, 'Output_Photos\10_final.jpg');
    %end
    
%     % MATLAB canny comparison
%     im = imread('Test_Photos/test1.jpg');
%     im = rgb2gray(im);
%     im = edge(im, 'canny');
%     figure; imshow(im);
%     title('MATLAB');
end
% Normalize matrix
function[A] = NormalizeMatrix(A)
    A = A/max(A(:));
end
% Perform sobel filter
function[A] = SobelFilter(A, filterDirection)
    switch filterDirection
        case 'x' 
            Gx = [-1 0 +1; -2 0 +2; -1 0 +1];
            A = imfilter(A, double(Gx), 'conv', 'replicate');
        case 'y'
            Gy = [-1 -2 -1; 0 0 0; +1 +2 +1];
            A = imfilter(A, double(Gy), 'conv', 'replicate');
        otherwise
            error('Bad filter direction - try inputs ''x'' or ''y''');
    end
end
% Find weak edges that are connected to strong edges and set them to 1
function[Gmag] = FindConnectedWeakEdges(Gmag, row, col)
    for i = -3:1:3
        for j = -3:1:3
            if (row+i > 0) && (col+j > 0) && (row+i < size(Gmag,1)) && ...
                    (col+j < size(Gmag,2)) % Make sure we are not out of bounds
                if (Gmag(row+i,col+j) > 0) && (Gmag(row+i,col+j) < 1)
                    Gmag(row+i,col+j) = 1;
                    Gmag = FindConnectedWeakEdges(Gmag, row+i, col+j);
                end
            end
        end
    end
end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2022-5-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1722655-can-someone-help-me-edit-the-code-below-so-that-the-output-image-can-display-the-value-of-rotation-a#answer_968580

I'd use bwferet and get the min angle. Let me know if you can't figure it out.

16 个评论
显示 14更早的评论隐藏 14更早的评论

Nurul Farhana Mohd Fadzli 2023-1-6

Did you know how to find angle without calling function? using formula maybe?

DGM 2023-1-6

If you open up bwferet(), you can basically see all the math involved in finding the feret properties. You might be able to make some simplifications if you could rely on your objects always being rectangles, or at least always being nominally convex.

请先登录，再进行评论。