Special issue on design and programming of signal processors for multimedia communication:Special issue on design and programming of signal processors for multimedia communication

The technical challenges in the design and programming of signal processors for multimedia communication are discussed. The development of terminal equipment to meet such demand presents a significant technical challenge, considering that it is highly desirable that the equipment be cost effective, power efficient, versatile, and extensible for future upgrades. The main challenges in the design and programming of signal processors for multimedia communication are, general-purpose signal processor design, application-specific signal processor design, operating systems and programming support and application programming. The size of FFT is programmable so that it can be used for various OFDM-based communication systems, such as digital audio broadcasting (DAB), digital video broadcasting-terrestrial (DVB-T) and digital video broadcasting-handheld (DVB-H). The clustered architecture design and distributed ping-pong register files in the PAC DSP raise new challenges of code generation.

Watermarking for Multimedia Security using Complex Wavelets

This paper investigates the application of complex wavelet transforms to the field of digital data hiding. Complex wavelets offer improved directional selectivity and shift invariance over their discretely sampled counterparts allowing for better adaptation of watermark distortions to the host media. Two methods of deriving visual models for the watermarking system are adapted to the complex wavelet transforms and their performances are compared. To produce improved capacity a spread transform embedding algorithm is devised, this combines the robustness of spread spectrum methods with the high capacity of quantization based methods. Using established information theoretic methods, limits of watermark capacity are derived that demonstrate the superiority of complex wavelets over discretely sampled wavelets. Finally results for the algorithm against commonly used attacks demonstrate its robustness and the improved performance offered by complex wavelet transforms.

Using location-aware technology for learning Geography in a real digital space outside the classroom

The use of new mobile technologies is still in its infancy in many secondary schools and there is limited evidence of the educational and pedagogical benefits on pupils’ learning in the formal school context. This qualitative study focuses on the use of handheld devices to teach a topic in geography to an examination class. Action research combined with pupil observations and focus group interviews are used to capture the pupils’ experiences of using mediascapes. Activity Theory is used as a lens to structure the analysis of the data and to report on the cognitive and affective impact of m-learning on pupils’ academic performance in the topic. Increased attainment and the development of wider skills for lifelong learning were identified in the study. The adaptability of the majority of pupils to the technology resulted in increased levels of willingness to learn in this novel context.

Promoting multicultural education in the primary classroom:Broadband videoconferencing facilities and digital video

The aim of this study was to explore the impact of interaction (through gathering local field data and engaging in remote reciprocal presentations) on aspects of multicultural awareness. Sixty-six 11-12-year-old Scottish primary school pupils collected data in the field from their local community through questionnaires, interviews, direct observation, digital images and video. From this they distilled a multimedia presentation, delivered by videoconference to a partner school in the USA, who reciprocated. There was some evidence of pre-post project gains in the complexity of the children's perceptions of their community environment, the ethnicity of their community, their own ethnicity, and news images. The children's use of language to define ethnicity also became more complex and their attitudes toward ethnic minorities became more inclusive. The implications for practice, policy and future research were explored. © 2004 Elsevier Ltd. All rights reserved.

Teachers’ Perspectives on Moving Image as a digital literacy tool in Creative Classrooms

Eight Creative Classroom (CCR) elements are used as a framework for analysing teachers’ current attitudes towards the use of moving images as a tool for teaching digital literacy to pupils aged 11-18 years in the context of ‘Creative Classrooms’. This paper reports on the challenges being faced by innovative teachers willing to adopt moving image (as a new ICT) into their teaching, and highlights the gaps currently present in the systemic support structures in schools which need to be addressed for innovative pedagogical practices to occur in these Creative Classrooms. By ensuring educators learn from their experiences of poor ICT uptake in the past and utilise these lessons for future innovations in classrooms, it is hoped that the transition to moving image, and its associated digital literacy skills, will be smooth and beneficial to the learners.