A New Still Image Coding Algorithm Based on Morphology
Yanchao Xing · 2002
Zerotree-Based wavelet coders, EZW and SPIHT, are two excellent coding algorithms currently, but the imperfect point is that they need more bits to express the parent-children relationship. The another coder based on the morphological representation of wavelet data (MRWD) is also successful, but the shortage is that it doesn't use the interband similarity of wavelet coefficients. In this paper, a new wavelet-based coder is developed by taking the advantages of the above coders and based on morphology. The main property of the new coder is that it uses following characteristics of wavelet coefficients: (1) within-subband clustering of significant coefficients; (2) cross-subband similarity; (3) decay of magnitude of wavelet coefficients across subband. The advantage of the new coder is to utilize the property of intraband clustering and interband similarity to predict the interband clusters based on morphological operator and then to overcome the shortages of the above three coders. Experimental results show that the performance of the new coder is superior to the above three coders. In specially, the new coder has the outstanding performance for the images including a large portion of texture. For example, for Barbara image 512×512, at 0.25b/p, the new coder outperforms EZW, SPIHT and MRWD by 1.68dB, 0.87dB, and 0.59dB.