Color Calibration for a Surrounding True-Color LED Display System by PWM Controls

With rapidly advancing computer technology, the demand for color images is growing with time for both quantity and quality, especially for various display panels. The purpose of this paper is to develop color calibration methods with hardware and software compensations for a surrounding true-color LED display system to enhance the performance of the true-color image display. To have an even LED lighting-time control and a linear relationship between RGB input value and output luminance, pulsewidth modulation driving schemes are employed in driving LED display. The color calibration techniques also include gamma correction for gradation of the luminance, compensation for the RGB input values on the basis of LED white point, and weighting filter to eliminate the interference from the adjacent LEDs. The experimental results indicate that the color-calibrated LED display system offers a very wide color gamut, and gives a great enhancement in color saturation and brilliance. For the color-calibrated LED display system, the display quality is obviously improved, and it exhibits a colorful and saturated color display.