Abstract: The invention discloses a numerical simulation method for the overflowing of river channel structures based on finite volume method. The method firstly acquires plane geometric data, river section data and structure geometric sizes of the river channel. The river channel is discretized by using the one-dimensional finite volume element, and the primitive variable values are stored in the center of the element, wherein the position of the river channel structures is taken as the element special interface. The amount of water passing through the structure interface in each time step is calculated according to the structure overflowing formula. This amount of water is respectively deducted from and increased to the upstream element and the downstream element adjacent to the interface by applying the source item method. The primitive variable values at the special interface are reconstructed by adopting the non-reflection boundary conditions in order to ensure the continuity of calculation.

Abstract: A screen area capturing an image including the screen area; obtaining candidate boundaries of the screen area; converting the candidate boundaries into straight lines; carrying out binary image processing with regard to the captured image; obtaining boundary pixels of a maximum target area, and letting the boundary pixels serve as an outline of the maximum target area; selecting straight lines on the outline from the converted straight lines; dividing the selected straight lines into four classes; and obtaining final straight lines by carrying out straight line fitting with regard to straight lines in the respective classes so as to obtain four boundaries of the screen area.

Abstract: Disclosed are a method and a system for detecting a screen area. The method comprises a step of capturing an image including the screen area; a step of obtaining candidate boundaries of the screen area; a step of converting the candidate boundaries into straight lines; a step of carrying out binary image processing with regard to the captured image; a step of obtaining boundary pixels of a maximum target area, and letting the boundary pixels serve as an outline of the maximum target area; a step of selecting straight lines on the outline from the converted straight lines; a step of dividing the selected straight lines into four classes; and a step of obtaining final straight lines by carrying out straight line fitting with regard to straight lines in the respective classes so as to obtain four boundaries of the screen area.