1. A method implemented on a device comprising: a. processing an input image using a block variance-based detection module; b. if the input image includes a stand-out object, conducting a block variance-based object of interest isolation; and c. otherwise, implementing a transition map-based detection comprising: i. generating a transition map based on a block difference between each block with neighboring blocks; ii. determining if an object portrait is detected based on the transition map; iii. if the object portrait is detected, then conducting the transition map-based object of interest isolation; and iv. if the object portrait is not detected, then the input image does not contain an object of interest.