An image enhancement apparatus is provided. The image enhancement apparatus includes a global tone mapping curve generator, a local tone mapping curve generator, a reference gamma voltage generator and an image generator. The global tone mapping curve generator generates a global tone mapping curve for an input image according to global characteristic(s) of the input image. The local tone mapping curve generator generates a local tone mapping curve for each image partition within the input image according to the global tone mapping curve and further a feature of the image partition. The reference gamma voltage generator generates a plurality of reference gamma voltages for each image partition according to the corresponding local tone mapping curve for the image partition. The image generator generates an output image according to the reference gamma voltages of the image partitions and the input image.