RESUMO
In this paper, we propose a H.264/AVC based compression technique adapted to coronary angiograms. H.264/AVC coder has proven to use the most advanced and accurate motion compensation process, but, at the cost of high computational complexity. On the other hand, analysis of coronary X-ray images reveals large areas containing no diagnostically important information. Our contribution is to exploit the energy characteristics in slice equal size regions to determine the regions with relevant information content, to be encoded using the H.264 coding paradigm. The others regions, are compressed using fixed block motion compensation and conventional hard-decision quantization. Experiments have shown that at the same bitrate, this procedure reduces the H.264 coder computing time of about 25% while attaining the same visual quality. A subjective assessment, based on the consensus approach leads to a compression ratio of 30:1 which insures both a diagnostic adequacy and a sufficient compression in regards to storage and transmission requirements.
Assuntos
Angiografia Coronária , Compressão de Dados/métodos , Sistemas de Informação em Radiologia , Gravação em Vídeo , Consulta RemotaRESUMO
In this paper, we introduce a novel approach to compress jointly a Multi-Channel Electrocardiogram (MCE) and an ultrasound image. We will show that this technique allows better performances, in terms of compression ratio (CR) compared to coding separately both modalities. In this approach, scaled ECG samples are inserted within the high frequencies of the ultrasound image after its decomposition on wavelet basis. The new standard JPEG2000 is then applied on the packed data for both coding and decoding purpose. Finally, the reconstruction quality is evaluated using the PSNR (Peak Signal Noise Ratio) and the PRD (Percent Root Mean Square Difference), respectively for both the ultrasound image and the ECG signals.