基于曲线演化的水平集算法近来已被广泛应用于图像分割中,针对其计算速度慢的问题,提出一种新的基于改进窄带法的图像分割方法INBM(Improved Narrow Band Method)。INBM首先将均匀采样的图像映射到对数极坐标系中,由视网膜空间分辨率机...基于曲线演化的水平集算法近来已被广泛应用于图像分割中,针对其计算速度慢的问题,提出一种新的基于改进窄带法的图像分割方法INBM(Improved Narrow Band Method)。INBM首先将均匀采样的图像映射到对数极坐标系中,由视网膜空间分辨率机制可知,注视点都在图像兴趣区,由此形成初始轮廓,然后用改进的窄带水平集(Level Set)方法演化曲线得到最终分割结果。改进窄带法是通过降低窄带区域内的水平集函数求解个数,来减少计算时间。实验结果表明,该方法大大提高了图像分割的速度。展开更多
Major peninsular rivers debouching into the Bay of Bengal through 2729 km long east coast of India, carry enormous inland flow and sediment from their alluvial basins. Present climate changes, storm irregularities and...Major peninsular rivers debouching into the Bay of Bengal through 2729 km long east coast of India, carry enormous inland flow and sediment from their alluvial basins. Present climate changes, storm irregularities and tsunamis have changed the hydrology of the coastal rivers. The hydrologic interventions for human need have reduced the sediment flow of the rivers resulting in sinking the deltas. Twelve important river basins in the east coast of India were identified. Linear and nonlinear regression equations were developed by stochastic approach of their annual flow (1986-2011) and yearly sediment influx (1993-2012) for the 12 rivers at their delta head. As results, the annual flow of the rivers from Subarnarekha to Godavari followed rational curves except the Brahmani River and Gaussian models for rivers from the Godavari to south except the river Vaigai. Similarly, the curve fitting models of time series for sediment had shown a change in curve pattern, the river Godavari being the line of demarcation. Gumbel II and Log Pearson type III methods were used to predict the flow and the sediment at various probabilities. Sediment prediction by Gumbel method had shown lower values than Log Pearson Type III methods for planning and design of hydraulic structures. The disparities in geologic formation of the central India and Deccan Plateau can be emphasized based on the statistical interpretations.展开更多
文摘基于曲线演化的水平集算法近来已被广泛应用于图像分割中,针对其计算速度慢的问题,提出一种新的基于改进窄带法的图像分割方法INBM(Improved Narrow Band Method)。INBM首先将均匀采样的图像映射到对数极坐标系中,由视网膜空间分辨率机制可知,注视点都在图像兴趣区,由此形成初始轮廓,然后用改进的窄带水平集(Level Set)方法演化曲线得到最终分割结果。改进窄带法是通过降低窄带区域内的水平集函数求解个数,来减少计算时间。实验结果表明,该方法大大提高了图像分割的速度。
文摘Major peninsular rivers debouching into the Bay of Bengal through 2729 km long east coast of India, carry enormous inland flow and sediment from their alluvial basins. Present climate changes, storm irregularities and tsunamis have changed the hydrology of the coastal rivers. The hydrologic interventions for human need have reduced the sediment flow of the rivers resulting in sinking the deltas. Twelve important river basins in the east coast of India were identified. Linear and nonlinear regression equations were developed by stochastic approach of their annual flow (1986-2011) and yearly sediment influx (1993-2012) for the 12 rivers at their delta head. As results, the annual flow of the rivers from Subarnarekha to Godavari followed rational curves except the Brahmani River and Gaussian models for rivers from the Godavari to south except the river Vaigai. Similarly, the curve fitting models of time series for sediment had shown a change in curve pattern, the river Godavari being the line of demarcation. Gumbel II and Log Pearson type III methods were used to predict the flow and the sediment at various probabilities. Sediment prediction by Gumbel method had shown lower values than Log Pearson Type III methods for planning and design of hydraulic structures. The disparities in geologic formation of the central India and Deccan Plateau can be emphasized based on the statistical interpretations.