1. A method to reduce image sticking in plasma display panels, said method comprising the steps of: converting a relationship between gray level and brightness of an input signal into a linear relation by a converter, making expected brightness based on gray level accurately predictable via a simple circuit; recording an image with a static image detector at time t using a frame buffer, and after a period of time Δt, comparing the image at time t with the image at time t+Δt, thereby identifying static or dynamic images in the pixel, wherein a compensation parameter for brightness regulation gains is a negative value if a static image is identified, and wherein the compensation parameter for brightness regulation gains is a positive value if a dynamic image is identified; and recording a gain of every pixel by a brightness regulator using an image gains memory buffer zone, said gain being regulated according to detection results of said static image detector, wherein a corresponding gain in the buffer zone is added to a corresponding brightness gain compensation coefficient c, when a static image is detected by said static image detector so as to minimize the gains, wherein the corresponding gain in the buffer zone is added to the corresponding brightness gain compensation coefficient c, when a dynamic image is detected by said static image detector so as to increase the gains, and wherein every pixel of an input image is multiplied by corresponding gains for output, thereby reducing brightness of the static image.