Abstract: A projection system and an image processing method thereof are provided. The system includes a projector module, a photography module and a processing module. The projector module projects a first image frame to an object surface. The photography module photographs the object surface to derive a second image frame including the first image frame and an indication point, wherein the indication point is formed by light projected on the object surface by an external device. The processing module analyzes the second image frame to derive coordinate of the indication point in the second image frame, derives coordinate of at least a feature point of the first image frame in the second image frame according to a linear-approximation method, and transforms the coordinates of the indication point in the second image frame to the coordinates in the first image frame by using two-dimensional coordinate transformation equations.

Abstract: The invention is directed to a method of storing videos for a portable device having a buffer memory space and a storage device The method comprises recording a plurality of video frames and storing the video frames into the buffer memory space of the portable device and detecting an event. According to the event, a portion of the video frames recorded from a first predetermined time before the event is detected until the event is detected is restored into the storage device as a plurality of pre-event video frames and, meanwhile, a plurality of post-event video frames is continuously recorded for a second predetermined time after the event is detected and the post-event video frames are stored into the storage device, wherein the storage device is coupled to the portable device.

Abstract: A projection system and an image processing method thereof are provided. The system includes a projector module, a photography module and a processing module. The projector module projects a first image frame to an object surface. The photography module photographs the object surface to derive a second image frame including the first image frame and an indication point, wherein the indication point is formed by light projected on the object surface by an external device. The processing module analyzes the second image frame to derive coordinate of the indication point in the second image frame, derives coordinate of at least a feature point of the first image frame in the second image frame according to a linear-approximation method, and transforms the coordinates of the indication point in the second image frame to the coordinates in the first image frame by using two-dimensional coordinate transformation equations.

Abstract: A switch includes a switch main body for use together with alternating current power source, and a circuit board; the main body includes a housing, a control member pivoted to one end of the housing, and several terminals secured on the other end of the housing; the control has a holding room therein, and a through hole communicating with the holding room; the circuit board is secured in the holding room of the control, and electrically connected to the terminals of the switch main body, and has a light emitting diode, which is held in the through hole of the control and used for helping people see the switch in the dark, and which is connected with a resistor with large resistance.