An efficient directional image interpolation method
Xiqun Lu, P.S. Hong, Mark J. T. Smith · 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). · 2003
The paper introduces a new method for interpolation in which the angular orientation of image features is exploited to enhance subjective quality. This involves, as a first step, extracting the low frequency information and expanding its size in a parallel channel. The mid to high frequency information is decomposed directionally into angular subbands. The subbands are then interpolated to enhance edge definition and then recombined. Experimental results show that the subjective quality of the interpolation is improved relative to conventional methods. Moreover, the interpolation method, when combined with JPEG compression, enables significantly higher coding performance to be achieved at low bit-rates - bit-rates at which JPEG typically breaks down.