Object-based coding is a promising technique for next-generation coding. Arbitrarily shaped texture coding is the key technique for object-based coding. This paper proposes a new technique, called "region support DCT", for arbitrarily shaped texture coding. The method is based on conventional 2D DCT, and has a special feature that the decoding process is achieved by a conventional DCT process. The proposed technique outperforms other techniques and involves low complexity in the decoder.