Abstract A method which reveals the visual masking in the human visual system (HVS) is useful in perceptual data coding. In this paper, we propose a color DCT-based method to estimate color spatio-temporal just noticeable distortion (JND) for video coding. The spatio-temporal JND profiles are assessed by incorporating a new temporal masking adjustment into the mathematical model of estimating the DCT-based spatial... A method which reveals the visual masking in the human visual system (HVS) is useful in perceptual data coding. In this paper, we propose a color DCT-based method to estimate color spatio-temporal just noticeable distortion (JND) for video coding. The spatio-temporal JND profiles are assessed by incorporating a new temporal masking adjustment into the mathematical model of estimating the DCT-based spatial JND profiles for luminance component and chrominance components of color images. In this paper, the new block-based temporal masking adjustment mainly considering the variation of local temporal statistics in luminance component between successive video frames is proposed. The spatiotemporal JND profiles are used to tune the H.264 video codec for higher performance. The simulation results demonstrate the performance of the perceptual video coding in terms of bit rates and visual quality. The bit rates required by the perceptually tuned video codec are lower than that required by the un-tuned video codec at nearly the same visual quality. Read More Read Less

Abstract Emerging High efficiency video coding (HEVC) is expected to be widely adopted in network applications for high definition devices and mobile terminals. Thus, construction of HEVC’s encryption schemes that maintain format compliance and bit rate of encrypted bit stream becomes an active security’s researches area. This paper presents a novel selective encryption technique for HEVC videos, based on enciphering the bins... Emerging High efficiency video coding (HEVC) is expected to be widely adopted in network applications for high definition devices and mobile terminals. Thus, construction of HEVC’s encryption schemes that maintain format compliance and bit rate of encrypted bit stream becomes an active security’s researches area. This paper presents a novel selective encryption technique for HEVC videos, based on enciphering the bins of selected Golomb–Rice code’s suffixes with the Advanced Encryption Standard (AES) in a CBC operating mode. The scheme preserves format compliance and size of the encrypted HEVC bit stream, and provides high visual degradation with optimized encryption space defined by selected Golomb–Rice suffixes. Experimental results show reliability and robustness of the proposed technique. Read More Read Less

Abstract Building maintenance is the responsibility of its owner which must use, whenever appropriate, a technician to perform the inspection. A good maintenance depends on the analysis of the anomalies detected during the inspection of the site. Building Information Models (BIM) have revealed themselves as a good tool when it comes to supporting maintenance actions, due to their ability to store enough... Building maintenance is the responsibility of its owner which must use, whenever appropriate, a technician to perform the inspection. A good maintenance depends on the analysis of the anomalies detected during the inspection of the site. Building Information Models (BIM) have revealed themselves as a good tool when it comes to supporting maintenance actions, due to their ability to store enough information in one digital model. The aim of the proposed work was to implement the benefits provided by BIM on a software tool used as support to maintenance of buildings. During an inspection activity for maintenance purposes, the implemented application, containing a rigorous database, allows the user to identify each anomaly present in building components, directly onto the BIM model, automatically associating them with probable causes, repair methods and a photograph of the anomaly uploaded at the site. Therefore, gains in productivity and a decrease in the error probability can be achieved. The inspection data is stored in the BIM model, making it suitable for consultation when planning maintenance. Additionally, it was case study the interoperability between BIM modelling and visualizing software, regarding the preservation of information, especially in the standard format Industry Foundation Classes (IFC). This work contributed to demonstrate, not only that there are still problems concerning the interoperability between BIM software, but also the advantages of employing BIM for building maintenance purposes. Read More Read Less