ImageTrim

ImageTrim[image,roi] gives the smallest subimage of image that includes the specified region of interest roi.

ImageTrim[image,roi,r] adds a margin of size r back to the resulting image.

ImageTrim[image,{roi1,roi2,…},…] extracts multiple subimages specified by roii from image.

ImageTrim[video,…] extracts the subimages from video.

Please visit the official Wolfram Language Reference for more details and examples on core symbols.