how to crop a particular location of a image?

I have drawn a star on a image and i want to crop that star region alone. How to do it?

[Andrei Bobrov]

use function crop from Image Processing Toolbox

[KIRAN kumar]

select the area first by selecting the star by defining it then perform corp.u can use image segmentation process for this

Answer 1

[Image Analyst]

Use max() and min() to find the extremes of the coordinates you drew. Then you can create a box and use imcrop(). You know that cropping gives you a matrix which is a rectangular shape, right?

Answer 2

[Walter Roberson]

poly2mask() and use the resulting mask to extract pixels from the image. You will probably also want to calculate the bounding box of the mask and create a rectangular area that size to store the extracted pixels in (as it is not possible to have a matrix which is an irregular shape.)

[Image Analyst]

Just noticed this was 4 months old. I have no idea how both of us could have missed it back then.

[Walter Roberson]

I saw it back then but I was busy and I figured someone else would answer.

[Sivakumaran Chandrasekaran]

Even though it is late, I thank you both Image Analyst and Walter.