> Hi all, > >Good day all. I am currently working on my final year project on >optical music recognition which involves decoding a musical score >into output of notes to be played in MIDI form. > >The first step I have researched towards decoding the image is to >first remove the staves lines of a digital musical image. I used >hough transform to detect the lines basically and then, with the >starting and ending points of the various lines detected, I assigned >a value of '255'(equivalent to assigning white colour to them) to >these lines, thus they are deleted. > >However, I have one serious problem, it works on a particular music >image, but it does not work correctly in detecting lines for other >musical images. Please help. I need some help in detecting the stave >lines correctly in every musical image. Thanks a million in advance. > >P/s: I have cut and paste my code below for your kind reference. >Thanks. > >Best Regards, >Johnny > >I = imread('epleasure_scanned.gif'); >rotI = imrotate(I,0,'crop'); >T=[0.0005 0.001]; >BW = edge(I,'canny',T,0.5); >[H,T,R] = hough(BW); >figure(1); >imshow(H,[],'XData',T,'YData',R,'InitialMagnification','fit'); >xlabel('\theta'), ylabel('\rho'); >axis on, axis normal, hold on; >P = houghpeaks(H,11,'threshold',ceil(0.1*max(H(:)))); >x = T(P(:,2)); y = R(P(:,1)); >plot(x,y,'s','color','white'); >% Find lines and plot them >lines = houghlines(BW,T,R,P,'FillGap',150,'MinLength',80); > > >figure(2); imshow(rotI), hold on >max_len = 0; >for k = 1:length(lines) >xy = [lines(k).point1; lines(k).point2]; > >I((xy(1,2)-1) : (xy(1,2)+1), xy(1,1): (xy(2,1)+1)) = 255; >plot(xy(:,1),xy(:,2),'LineWidth',1,'Color','green'); > >% Plot beginnings and ends of lines >plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow'); >plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red'); > >% Determine the endpoints of the longest line segment >len = norm(lines(k).point1 - lines(k).point2); >if ( len > max_len) >max_len = len; >xy_long = xy; >end >end > >% highlight the longest line segment >plot(xy_long(:,1),xy_long(:,2),'LineWidth',2,'Color','cyan'); >figure(3); >imshow(I) >figure(4); >imshow(BW); > > Hi sweesun2002, did you manage to solve problem ? I'm interested in results of your project.I'm doing similar thing, but i'm not doing well. Start a New Thread

Hi all,

Good day all. I am currently working on my final year project on
optical music recognition which involves decoding a musical score
into output of notes to be played in MIDI form.

The first step I have researched towards decoding the image is to
first remove the staves lines of a digital musical image. I used
hough transform to detect the lines basically and then, with the
starting and ending points of the various lines detected, I assigned
a value of '255'(equivalent to assigning white colour to them) to
these lines, thus they are deleted.

However, I have one serious problem, it works on a particular music
image, but it does not work correctly in detecting lines for other
musical images. Please help. I need some help in detecting the stave
lines correctly in every musical image. Thanks a million in advance.

P/s: I have cut and paste my code below for your kind reference.
Thanks.

Best Regards,
Johnny

I = imread('epleasure_scanned.gif');
rotI = imrotate(I,0,'crop');
T=[0.0005 0.001];
BW = edge(I,'canny',T,0.5);
[H,T,R] = hough(BW);
figure(1);
imshow(H,[],'XData',T,'YData',R,'InitialMagnification','fit');
xlabel('\theta'), ylabel('\rho');
axis on, axis normal, hold on;
P = houghpeaks(H,11,'threshold',ceil(0.1*max(H(:))));
x = T(P(:,2)); y = R(P(:,1));
plot(x,y,'s','color','white');
% Find lines and plot them
lines = houghlines(BW,T,R,P,'FillGap',150,'MinLength',80); figure(2); imshow(rotI), hold on
max_len = 0;
for k = 1:length(lines)
xy = [lines(k).point1; lines(k).point2];

I((xy(1,2)-1) : (xy(1,2)+1), xy(1,1): (xy(2,1)+1)) = 255;
plot(xy(:,1),xy(:,2),'LineWidth',1,'Color','green');

% Plot beginnings and ends of lines
plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red');

% Determine the endpoints of the longest line segment
len = norm(lines(k).point1 - lines(k).point2);
if ( len > max_len)
max_len = len;
xy_long = xy;
end
end

% highlight the longest line segment
plot(xy_long(:,1),xy_long(:,2),'LineWidth',2,'Color','cyan');
figure(3);
imshow(I)
figure(4);
imshow(BW);



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