1. An image scaling method for producing a digital target image by scaling a digital source image in an embedded system, the method comprising the steps of: a) determining respective sizes of minimum processing units of a source image and a target image so that the source image and the target image are divided into a same number of minimum processing units in respective lateral and longitudinal directions according to a scaling ratio of the source image size to the target image size; b) obtaining integer weight values, each weight value corresponding to each of points uniformly divided between two adjacent pixels, being a value in a range of 0˜2 n wherein n is a natural number, and a sum of the weight values between two adjacent pixels is 2 n ; and c) producing the target image by obtaining target pixel values of each of the minimum processing units of the target image corresponding to the minimum processing units of the source image by using a source pixel value reflected on a corresponding target pixel value, with the weight value corresponding to a distance with the source pixel.