plot pixel values in circular image
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Hi all
I have multiple lines each size is 512x1. I want to plot them with a degree increment to make a circular shape image. But don't know how to plot them. Can anyone help me?

Answers (1)
Image Analyst
on 14 May 2018
Use sind() and cosd() to create the x and y endpoints of the line, x1,x2,y1,y2. Then call
line([x1,x2], [y1,y2], 'Color', 'k', 'LineWidth', 2)
Sounds like homework, so give it a try yourself. Have a for loop over all angles. Here's a start:
for angle = 1 : 20 : 360
x1 = lineLength * cosd(angle......
line([x1,x2], [y1,y2], 'Color', 'k', 'LineWidth', 2)
hold on;
end
10 Comments
Alina tom
on 15 May 2018
Image Analyst
on 15 May 2018
If it's not your homework, you can use this:
lineLength = 512;
for angle = 0 : 22.5 : 360
fprintf('Drawing line at angle %.1f degrees.\n', angle);
x1 = lineLength * cosd(angle);
y1 = lineLength * sind(angle);
x2 = -x1;
y2 = -y1;
line([x1,x2], [y1,y2], 'Color', 'k', 'LineWidth', 3)
hold on;
end
grid on;

It draws the lines in a graph. It does not use the original image. I didn't see that as being necessary. Nor does it create an image. You can use getframe() if you want to get it as an image.
Alina tom
on 16 May 2018
Ameer Hamza
on 16 May 2018
What does " each size is 512x1" means? Is the image just 1 pixel wide? Also, the code in answer produces a similar image as you showed in your question. If there is a different pattern, then share an example image of what you want finally. An example output greatly helps in suggesting a correct solution.
Alina tom
on 16 May 2018
Image Analyst
on 16 May 2018
I have no idea. That's not even remotely close to the spokes and lines images you posted before. I'm not sure what to do with this blob outline image. You'll need to expand/clarify your need a lot more for us to help you.
Alina tom
on 16 May 2018
Alina tom
on 16 May 2018
Image Analyst
on 16 May 2018
See if my copy and paste demo works for you. You can cut out a line, rotate it, and paste it onto a canvass image, if that's what you want to do.
Alina tom
on 17 May 2018
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