Enlargement and reduction of image/video via discrete cosine transform pair, part 1: novel three-dimensional discrete cosine transform and enlargement

摘要

We propose novel matrix-form representations of the conventional forward three-dimensional (3-D) discrete cosine transform (DCT) and the inverse 3-D DCT. The pair of the computationally efficient 3-D DCTs causes the formulation to be more concise with a systematic structure, which has a high potential for the development of other applications via the 3-D DCT pair. Applications for enlargement of image/video implemented by the DCT pair are also presented. These new algorithms effectively eliminate ripple and blocky effects and maintain the original characteristic. Moreover, due to the essentially even-function property of the DCT, the proposed enlargement of an image demonstrates the desired symmetric property. As a result, they can also find numerous applications in image processing and video coding. Simulation results show that proposed mechanisms enable good performance for scaling algorithms of sequences, images, and videos, as expected.