Implementation of a new contrast enhancement method for video images

Based on the Histogram Equalization (HE) method, the study has proposed a new contrast enhancement technique named Adaptively Increasing the Value of Histogram Based on Histogram Equalization (AIVHE). AIVHE offers a gradually increment to modify the original probability density function (PDF) of the image. The input image can produce the effect of contrast enhancement effectively by automatic adaptive incrimination. In the meantime, the method can obtain more gray level distribution of dark and bright regions as well as increase gray levels effectively. This article modifies the method of AIVHE from the view of hardware design. The modification can not only keep the enhancement effect of AIVHE, but also simplify the implementation to achieve the demand of high quality display for video images. This study also verified the design and valuated the performance of the modified method by means of a TFT-LCD development platform. The implementation showed that the modified method can work by 44.045MHz which is 3.28 times faster than the demand of SDTV NTSC 720*480i specification, the speed is 1.66 times faster than the demand of EDTV NTSC 720*480p specification.