System and method of estimating the three-dimensional size of an object for packaging or storing the object

The invention discloses a system and method for estimating a three-dimensional (3D) packaging size of an object. The method has a self calibration function to correct the scale in the measurement environment so as to reduce errors caused by human operations. The system comprises an image capture unit for capturing images of the measurement environment and objects; a scale correction unit for performing the calibration using a reference object of a known size; and an object size estimation unit for detecting the position of an object to be estimated in the image data received from the image capture unit and estimating the 3D size of the object according to the calibrated scale.