Hi 준수
You can draw a perfect circle by creating a binary mask where the circle is represented by ones and the rest of the matrix is zeros. This binary mask can be used in PIVlab or other image processing applications to observe specific regions, such as a droplet flow on a flat surface.
To create a circle mask, you can use the following code snippet:
% Define the dimensions of the image (mask)
imageWidth = 512; % Width of the image in pixels
imageHeight = 512; % Height of the image in pixels
% Define the properties of the circle
centerX = imageWidth / 2; % X coordinate of the circle's center
centerY = imageHeight / 2; % Y coordinate of the circle's center
radius = 50; % Radius of the circle in pixels
% Create a grid of coordinates corresponding to the image dimensions
[xGrid, yGrid] = meshgrid(1:imageWidth, 1:imageHeight);
% Calculate the binary mask where the circle pixels are 1 and others are 0
circleMask = (xGrid - centerX).^2 + (yGrid - centerY).^2 <= radius^2;
% Display the binary mask as an image
imshow(circleMask);
% If you need to save the mask to a file, you can use the following code:
% imwrite(circleMask, 'circleMask.png');
You can also use "viscircles" function to create circles with specified centers and radii. Refer to the below official MathWorks documentation to know more about "viscircles" function:
Hope this helps!
