What does projector keystone correction mean? Does it affect the image quality?

1. What is keystone correction

In the daily use of the projector, the position of the projector should be at right angles to the projection screen as much as possible to ensure that the projection screen is square. If the perpendicularity of the two cannot be guaranteed, the screen will produce a trapezoid. Then it is necessary to correct the picture at this time to ensure that the picture becomes a standard rectangle, which is keystone correction.

2. The principle of trapezoidal correction

First of all, we need to know that there are usually two methods of keystone correction: optical keystone correction and digital keystone correction.

Optical Keystone Correction: It refers to the purpose of adjusting the trapezoid by adjusting the physical position of the lens, also called shifting, which is the same as the shifting lens of the camera.

Digital keystone correction: the principle is to geometrically transform the original image by an interpolation algorithm for the trapezoidal distortion to be generated by the projection optical path of the projector, and generate a reverse compensation trapezoidal image to compensate for the trapezoidal distortion of the image generated by the projection optical path, so that the projected image Renders a regular rectangle.