Location of object leaving a specific point

Hi. For example i set the peripheral of a circle my set point. Does anyone knows how can i get the locations of the some balls when are leaving this circle? Any help will be appreciated. Thanks a lot

[José-Luis]

Some background information might be useful to help us understand what it it you want. What is the "peripheral of a circle"? Its perimeter? In that case just compute the distance to the center and check that it's smaller than its radius.

[ZENONAS ZENIOU]

Yeah you are right i need to explain more. For example some balls will be passed through a a circle shape. Basically i need to find the location of the ball and where they left the circle shape. I don't know if you understand more with this.

[José-Luis]

Sorry, I don't understand. "Where they left" seems to imply movement. Are you talking about a video?

Usually, it is better to provide a snippet of code reproducing your problem. Makes it easier for us to help you.

[ZENONAS ZENIOU]

i didn't prepare the code so far because its difficult for me as i am new in matlab. Yes its a video and the balls will moving through this circle shape. And i need to find the location of these as they leaving (exiting) this circle.

[José-Luis]

Sorry, not my area of expertise. Maybe some other contributor will bite.

Answer 1

[Image Analyst]

Use hypot() or sqrt() to determine the distance of the centroid of your blob from the center of your circle. When that distance is more than the radius of the circle, it is not "inside" the circle.

You might like to see several things in the FAQ on circles: http://matlab.wikia.com/wiki/FAQ#How_do_I_create_a_circle.3F