An image scaling method and apparatus converting an input image into an aimed image with suitable resolution for application, in the case that the input image and the aimed image are different in resolution, using continuous domain filtering and interpolation method. The invention utilizes domain filter of regular square type and generates filter coefficient based on area occupancy ratio of filter window according to the area of corresponding pixel extending the applied filter window and then obtains scaled image through the method of computing weighted average value, which is determined through multiplication of the generated filter coefficient and value of each pixel. By using image scaling method of the invention, there is an advantage of much lower cost in hardware implementation of an image scaler in comparison with conventional image scaling methods.