An edge-enhancement device for subjecting input image data to edge enhancement so as to generate output image data has an edge-component generator, a weighting processor, and an addition processor. The input image data is obtained from a frame image having a plurality of pixels, and the input image data contains luminance data. The edge-component generator generates an edge component of the input image data. The weighting processor applies a weight according to the value of the luminance data of each pixel to a calculated edge component of each pixel so as to generate a weighted edge component for each pixel. The addition processor adds the weighted edge component of each pixel to the input image data of the pixel so as to generate the output image data.