Patent ID: 6914611

Claim:
An apparatus for identifying four coordinates of a window displayed on a monitor, said apparatus comprising: a generator configured to generate gradient values indicative of changes in pixel data of at least one image displayed on said monitor for pixels that are adjacent in horizontal and in vertical directions; a memory being configured to store said gradient values; and a detector configured to detect a first unique configuration in said gradient values to identify three coordinates of one edge of said window; said detector being configured to check in a direction perpendicular to said one edge to detect a second unique configuration in said gradient values to determine a fourth coordinate of said window, wherein said first unique configuration includes a first line of consecutive first level of gradients, and a second line gradients including at least one first gradient having said first level at a perpendicular location from a first end of said consecutive gradients and at least one second gradient having said one level at a diagonal location from a second end of said consecutive gradients.