A scaling device for video displays includes a limited number of line buffers and produces stable output frames by using a stable clock source to produce the output image clock. The scaling device further includes an error counter for determining an error between an ideal output line length and an actual line length and an error accumulator for keeping a running total of all output line length errors. The error accumulator can signal when the total line error for a given frame is greater than one, indicating that an additional output point should be added to the blanking area of that output line.