Patent ID: 6999107

Claim:
A method of scaling an image signal, comprising: storing the image signal in an image signal memory; receiving a source scaling factor having a numerator and a denominator, the numerator and the denominator being positive integers; calculating upper and lower approximate simplified scaling factors, the upper approximate simplified scaling factor being a fraction, greater than the source scaling factor, having a numerator less than the numerator of the source scaling factor and a denominator less than the denominator of the source scaling factor, the lower approximate simplified scaling factor being a fraction, less than the source scaling factor, having a numerator less than the numerator of the source scaling factor and a denominator less than the denominator of the source scaling factor; calculating repetition counts indicating how often the upper and lower approximate simplified scaling factors are to be used; generating, from the upper and lower approximate simplified scaling factors, address information for reading reference pixels from the image signal stored in the image signal memory, a selection signal selecting the upper approximate simplified scaling factor or the lower approximate simplified scaling factor, and phase information indicating where pixels are to be interpolated in relation to the reference pixels; generating interpolation coefficients according to the upper and lower approximate simplified scaling factors and the phase information; reading the reference pixels from the source image signal memory according to the address information; and performing interpolation on the reference pixels, using the interpolation coefficients corresponding to the approximate simplified scaling factor selected by the selection signal, and outputting interpolated pixels.