Side window display system on vehicle

A vehicle side window display system, comprising:

• a transparent display disposed on a side window of a vehicle;
• at least one external sensor detecting an external environment of the vehicle to provide external environment information;
• at least one internal sensor detecting an internal environment of the vehicle to provide internal environment information;
• a controller coupled to the transparent display, the at least one external sensor and the at least one internal sensor to select an operation mode based on the internal environment information, and control a transparency distribution and a brightness distribution of the transparent display based on the operation mode and the external environment information;
• wherein when the controller determines that the vehicle is in a parking state, the controller determines whether a passenger is to open a door and determines whether a car is coming from behind the vehicle, wherein the passenger is to open the door is determined by a door-opening intention score based on the passenger's gaze area, the passenger's face angle, a turning angle of the passenger's body, and a distance between the passenger's hand and a door handle.