1. An image enhancement apparatus, comprising: a global contrast curve generator generating a global contrast curve for an input image according to a global histogram of the input image; a local contrast curve generator generating a local contrast curve for each image partition within the input image according to the global contrast curve and further a feature of the image partition; and an image generator generating an output image by enhancing a contrast of each image partition according to the local contrast curve for the image partition and the input image, and merging the enhanced image partitions.