A sample key signal frame (602) and/or a sample image frame (601) may be stored showing a finely detailed element (101) at a first resolution (e.g. a zoomed-in image). A current image signal (71) includes the same finely-detailed element (101) at a second, lower, resolution (e.g. a wide-angle image). The sample (601, 602) is scaled and/or transformed to match a target area (10,14) within the current image (71), and may be used to perform an image enhancement process which enhances the detailed element (101) within an enhanced modified image frame (74). Thus, a more photo-realistic image is achieved.