This paper discusses a robust technique using entropy-based detection for delineating edges in ocean colour images. The detection process relies on Jhensen-Shannon divergence based image segmentation, which has been f...This paper discusses a robust technique using entropy-based detection for delineating edges in ocean colour images. The detection process relies on Jhensen-Shannon divergence based image segmentation, which has been found to be the most suitable for noisy ocean colour images. In the attempted technique, partial removal of the noise in the images is performed and the edges are detected using entropic method. In our approach, Jhensen-Shannon divergence for the images is calculated, and the divergence image is arrived at after applying an appropriate threshold and filter to estimate the gradients. An attempted case study on retrieving chlorophyll front edges using this technique indicates that entropic method is far superior to conventional edge-enhancement tools, in terms of its insensitivity to impulsive noises and, capability in detecting meso- and micro-scale changes. This procedure would largely decrease the ambiguities associated with the ocean colour edges and hence has promising application potential in targeting fishing zones, sediment dispersion modeling and climate related studies.展开更多
The vital role of anthocyanins in <i>Hibiscus sabdariffa</i> L. is now known to most consumers. The richness of anthocyanins in antioxidants, vitamin C, minerals, etc., provides <i>Hibiscus</i>...The vital role of anthocyanins in <i>Hibiscus sabdariffa</i> L. is now known to most consumers. The richness of anthocyanins in antioxidants, vitamin C, minerals, etc., provides <i>Hibiscus</i> juice with proven nutritional qualities. The health requirements of recent years have made food products with added preservatives or processed at high temperatures less popular, thus explaining the new <span>orientations towards innovative and interdisciplinary technologies. Antho</span>cyanins from <i>Hibiscus sabdariffa</i> L. are, however, sensitive to degradation factors such as temperature, light, enzymes and also oxygen. The instability of <span>anthocyanins has long been a subject of research using classic techniques</span> such as heat treatment, the results of which are often limited by the rapid degradation and above all the destruction of the nutritional and organoleptic qualities of the product. Oxygen dissolved in juices is so far treated by bubbling with an inert gas or by adding other molecules such as preservatives which can cause a lot of health damage. The electrochemical approach is a <span>new stabilisation technique that reduces the dissolved oxygen in the juice</span>, cold and without the addition of other molecules. The electrolysis of <i>Hibiscus</i> juice was carried out by noble electrodes (Platinum and Stainless Steel) with a well-<span>characterised Time/Potential or Time/Intensity couple. The electroreduced</span> samples and the control were then stored at 4°C, 25°C and 37°C for more than 6 months. Monitoring of anthocyanins in the first month, of the samples and the control, showed a significant difference of 10% between the electroreduced extract and the untreated control at 37°C, which had previously been problematic for the heat treatment and even for the other membrane techniques. Oxygen reduction on the platinum electrode/ECS allowed the retention of more than 10% of anthocyanins after 4 weeks of storage at 25°C and 37°C. At 4°C, a significant difference of 5% between the electro-reduced <i>Hibiscus</i> juice and the control was maintained until the fifth month of storage <span>with the 1/5 ratio (calyx/water). Non-significant losses in anthocyanin (10</span> mg/l), for the juice with reduced dissolved oxygen, were noted for the 1/5 and 1/15 ratios during the first month of storage at 4°C against 24 mg/l of significant losses for the 1/20 ratio. However, the untreated control showed significant losses for the ratios 1/20, 1/15 and 1/5. Oxygen dissolved in the juice therefore considerably degrades the anthocyanins of <i>Hibiscus sabdariffa</i> L<span style="font-size:10.0pt;font-family:;" "="">.</span><span style="font-size:10.0pt;font-family:;" "=""> from the first month of storage at 4°C.</span>展开更多
文摘This paper discusses a robust technique using entropy-based detection for delineating edges in ocean colour images. The detection process relies on Jhensen-Shannon divergence based image segmentation, which has been found to be the most suitable for noisy ocean colour images. In the attempted technique, partial removal of the noise in the images is performed and the edges are detected using entropic method. In our approach, Jhensen-Shannon divergence for the images is calculated, and the divergence image is arrived at after applying an appropriate threshold and filter to estimate the gradients. An attempted case study on retrieving chlorophyll front edges using this technique indicates that entropic method is far superior to conventional edge-enhancement tools, in terms of its insensitivity to impulsive noises and, capability in detecting meso- and micro-scale changes. This procedure would largely decrease the ambiguities associated with the ocean colour edges and hence has promising application potential in targeting fishing zones, sediment dispersion modeling and climate related studies.
文摘The vital role of anthocyanins in <i>Hibiscus sabdariffa</i> L. is now known to most consumers. The richness of anthocyanins in antioxidants, vitamin C, minerals, etc., provides <i>Hibiscus</i> juice with proven nutritional qualities. The health requirements of recent years have made food products with added preservatives or processed at high temperatures less popular, thus explaining the new <span>orientations towards innovative and interdisciplinary technologies. Antho</span>cyanins from <i>Hibiscus sabdariffa</i> L. are, however, sensitive to degradation factors such as temperature, light, enzymes and also oxygen. The instability of <span>anthocyanins has long been a subject of research using classic techniques</span> such as heat treatment, the results of which are often limited by the rapid degradation and above all the destruction of the nutritional and organoleptic qualities of the product. Oxygen dissolved in juices is so far treated by bubbling with an inert gas or by adding other molecules such as preservatives which can cause a lot of health damage. The electrochemical approach is a <span>new stabilisation technique that reduces the dissolved oxygen in the juice</span>, cold and without the addition of other molecules. The electrolysis of <i>Hibiscus</i> juice was carried out by noble electrodes (Platinum and Stainless Steel) with a well-<span>characterised Time/Potential or Time/Intensity couple. The electroreduced</span> samples and the control were then stored at 4°C, 25°C and 37°C for more than 6 months. Monitoring of anthocyanins in the first month, of the samples and the control, showed a significant difference of 10% between the electroreduced extract and the untreated control at 37°C, which had previously been problematic for the heat treatment and even for the other membrane techniques. Oxygen reduction on the platinum electrode/ECS allowed the retention of more than 10% of anthocyanins after 4 weeks of storage at 25°C and 37°C. At 4°C, a significant difference of 5% between the electro-reduced <i>Hibiscus</i> juice and the control was maintained until the fifth month of storage <span>with the 1/5 ratio (calyx/water). Non-significant losses in anthocyanin (10</span> mg/l), for the juice with reduced dissolved oxygen, were noted for the 1/5 and 1/15 ratios during the first month of storage at 4°C against 24 mg/l of significant losses for the 1/20 ratio. However, the untreated control showed significant losses for the ratios 1/20, 1/15 and 1/5. Oxygen dissolved in the juice therefore considerably degrades the anthocyanins of <i>Hibiscus sabdariffa</i> L<span style="font-size:10.0pt;font-family:;" "="">.</span><span style="font-size:10.0pt;font-family:;" "=""> from the first month of storage at 4°C.</span>
