An image processing apparatus includes an image decoding unit and an image adjusting unit. The image decoding unit decodes a data stream to generate a first image comprising a first pixel. The image adjusting unit comprises a pixel edge determining module and a chrominance adjusting module. The pixel edge determining module determines an edge luminance parameter according to an initial luminance value of the first pixel and a plurality of initial luminance values of pixels neighboring the first pixel, and determines an edge chrominance parameter according to an initial chrominance value of the first pixel and a plurality of initial chrominance values of pixels neighboring the first pixel. The first chrominance adjusting module determines a first weight according to the edge luminance parameter and the edge chrominance parameter, and generates a first adjusted chrominance value by weighted calculating a first predetermined chrominance value and the initial chrominance value of the first pixel.