1. A method of capturing an image displayed on an external display device and detected by an electronic device, the method comprising: generating image data associated with the detected image using the electronic device; detecting, by the electronic device, a first group of boundary markers displayed by the external display device, the first group of boundary markers being periodically displayed to be undetectable by a human eye that is viewing the external display device; in response to detecting the first group of boundary markers, determining image regions associated with the generated image data including a first image region circumscribed by the first group of boundary markers and a second image region being distinct from the first image region; and modifying, regional image data associated with at least one of the first image region or the second image region to contrast with regional image data of another determined image region.