Text skew detection and correction in image

Question

Yahya 2022-11-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1856603-text-skew-detection-and-correction-in-image

评论： Image Analyst 2022-11-22

clc;clear all; close all;
a=imread('eq2.jpg');
figure;
imshow(a)
if size(a,3)==3
    a=rgb2gray(a);
end
b=im2bw(a);
ar=imrotate_white(b,30);
figure
imshow(ar);
br=~(ar);
figure
imshow(br)
[r c]=size(b);
X=[];
for i=1:r
    for j=1:c
        if br(i,j)==1;
            X=[X; i j];
        end
    end
end
size(X);
[coeff, score, latent]=pca(X);
figure;
biplot(coeff(:,1:2),'Scores',score(:,1:2),'VarLabels',{'v_1','v_2'});
r=sqrt((coeff(1,1))^2+(coeff(1,2))^2);
th=real(double(vpa(acos(coeff(1,1)/r)*180/pi)))
syms x
th=real(double(vpa(solve(x==th-90))))
rotatedImage=imrotate(br,-th);
figure
imshow(rotatedImage)
function rotated_image = imrotate_white(image, rot_angle_degree)
    RA = imref2d(size(image));    
    tform = affine2d([cosd(rot_angle_degree)    -sind(rot_angle_degree)     0; ...
                      sind(rot_angle_degree)     cosd(rot_angle_degree)     0; ...
                      0                          0                          1]);
      Rout = images.spatialref.internal.applyGeometricTransformToSpatialRef(RA,tform);
      Rout.ImageSize = RA.ImageSize;
      xTrans = mean(Rout.XWorldLimits) - mean(RA.XWorldLimits);
      yTrans = mean(Rout.YWorldLimits) - mean(RA.YWorldLimits);
      Rout.XWorldLimits = RA.XWorldLimits+xTrans;
      Rout.YWorldLimits = RA.YWorldLimits+yTrans;
      rotated_image = imwarp(image, tform, 'OutputView', Rout, 'interp', 'cubic', 'fillvalues', 255);
end