Contrast enhancement system and method for projector

A contrast enhancement system for a projector, the projector having a light source and providing a standard mode and an economic mode, the contrast enhancement system comprising:

• a detection module configured for detecting a gray level of a standby projection image of the projector;
• a determination module configured for comparing the detected gray level to a predetermined gray level, to determine whether the projector works in the standard mode or in the economic mode;
• a control module configured for directing the projector to work in the economic mode when the gray level is higher than the predetermined gray level, or directing the projector to work in the standard mode and to project a full light image when the gray level is lower than the predetermined gray level;
• a modulation module configured for increasing a gain of the non-white waveform of light from the light source by modulating the frequency of the light when the projector is working in the economic mode, to make the projector project a full dark image;
• a calculation module configured for calculating a first contrast value of the full light image, a second contrast value of the full dark image, and a total contrast of a plurality of projection images, wherein the total contrast is equal to the ratio of the first contrast value to the second contrast value;
• and
• an execution module configured for controlling the projector to project the projection images according to the calculated total contrast.