With broadband networks, audio/video coding, and processing techniques and user devices swiftly advancing, multimedia streaming over networks is now a reality. Distributed interactive multimedia applications ? one of the fastest growing market sectors demanding innovations ? are covered in this special issue on multimedia processing (MP).

This special issue focuses on ambitious and intriguing papers from experts on a wide variety of multimedia areas. These articles address innovations and offer effective solutions to MP problems.

Y. Fushio et al. propose a shadow generation system based on shape recognition, while M. Suzuki et al. develop musical expression generation reflecting the userfs impression in kansei space and fuzzy rules. K. Ishizuka et al. evaluate an operetta songs generation system based on the impressions given by story scenes, which are strongly related to the integrative research projects of kansei engineering, music, text, and visual perception.

T. Toyota et al. develop a web news visualization system based on an efficient self-organizing map using a restricted region search and dimensionality reduction. S. Kawauchi et al. propose a knowledge expansion support system using related search keyword generation based on Wikipedia categories and point-wise mutual information, involving that are aggressive looking progressive research projects covering huge text information. T. Tanabata et al. present an interactive data mining tool for microarray data analysis using formal concept analysis, which adds a new dimension to the bio-informatics field.

T. Kawamura et al. analyze keywords input to a book search engine. T. Sugimoto et al. propose a recommendation system involving the use of comprehensive trend indications based on weighted complete graphs, which are related to topical discussions in the information retrieval and recommendation field.

Readers are sure to find new and valuable information and ideas in their own fields in these excellent articles.