MATLAB Answers

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?


use function crop from Image Processing Toolbox

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

2 Answers

Answer by Image Analyst
on 18 Jan 2013
 Accepted answer

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 by Walter Roberson
on 18 Jan 2013

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.)


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

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

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

Join the 15-year community celebration.

Play games and win prizes!

Learn more
Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

MATLAB Academy

New to MATLAB?

Learn MATLAB today!