1. A mobile handheld device having a scenario simulation system, the mobile handheld device having communication functionality such that the mobile handheld device is operative to make a call, the mobile handheld device comprising: an outline detection device configured to analyze and separate a plurality of images retrieved from an image input device of the mobile handheld device into a plurality of foreground and background images; a foreground storage medium configured to store the foreground images; a background storage medium configured to store the background images; a foreground selector configured to select a foreground image from the foreground storage medium; a background selector configured to select a background image from the background storage medium; an image mixer configured to mix the foreground image with the background image as an output image; and an image output module configured to transmit, while a call of the mobile handheld device is in progress, the output image to a remote multimedia device for replacing a real image on the remote multimedia device; wherein the outline detection device comprising a feature extracting unit, an outline modeling unit, a texture constraining unit which is further collocated to constrain textures that are hard to be removed by the outline modeling unit, and a criterion detecting and connecting unit.