Methods and systems are disclosed for segmenting an image. First and second frames of image data are generated at different times. A first portion of the first frame is compared to image data of the second frame, and a second portion of the second frame is selected based on the comparison. A displacement vector between the first portion and the second portion is calculated, where the displacement vector represents relative movement over time between the image data represented by the first portion and the image data represented by the second portion. An image is output with an indicator, and the location of the indicator on the image is determined by using the calculated displacement vector. The indicator can serve to distinguish between items in an imaging view.