The invention relates to a system of capturing zoom-in images of an object. The system comprises a pan, tilt, zoom (PTZ) camera for capturing a video stream in view; an image-capture device for extracting and digitizing images from the video stream; an object detector for detecting objects in the images from the image-capture device, determining the locations and sizes of the objects and sending the locations and the sizes of the objects to a selector; the selector for determining one of the objects and sending the location and size of the one of the objects to a assessor; the assessor for determining the trajectories required to both align the one of the objects to the center of the image based on the current location of the one of the objects relative to the center and to maximize the size and resolution of the one of the objects according to the current size of the one of the objects, and for sending the trajectories to a translator; the translator for converting the trajectories into a signal stream with a command format that a camera controller can understand and for sending the converted trajectories to the camera controller; and the camera controller for moving and zooming the PTZ camera according to the signal stream, thereby the PTZ camera moves to center on the one of the objects and captures zoomed-in images of the one of the objects from the video stream.