Abstract :
A Letter by Agbinya (see ibid., vol.28, p.1927, 1992) misused the method of interpolation using the type I discrete cosine transform (DCT-I), and did not give a correct interpolation scheme using the conventional discrete cosine transform (DCT). The correct procedure of interpolation using the DCT-I is clarified, and an appropriate approach of interpolation using the DCT is given in this Letter.
