Selective Image Segmentation Models Using Three Distance Functions

Image segmentation can be defined as partitioning an image that contains multiple segments of meaningful parts for further processing. Global segmentation is concerned with segmenting the whole object of an observed image. Meanwhile, the selective segmentation model is focused on segmenting a specific object required to be extracted. The Convex Distance Selective Segmentation (CDSS) model, which uses the Euclidean distance function as the fitting term, was proposed in 2015. However, the Euclidean distance function takes time to compute. This paper proposed the reformulation of the CDSS minimization problem by changing the fitting term with three popular distance functions, namely Chessboard, City Block, and Quasi-Euclidean. The proposed models were CDSSNEW1, CDSSNEW2, and CDSSNEW3, which applied the Chessboard, City Block, and Quasi-Euclidean distance functions, respectively. In this study, the Euler-Lagrange (EL) equations of the proposed models were derived and solved using the Additive Operator Splitting method. Then, MATLAB coding was developed to implement the proposed models. The accuracy of the segmented image was evaluated using the Jaccard and Dice Similarity Coefficients. The execution time was recorded to measure the efficiency of the models. Numerical results showed that the proposed CDSSNEW1 model based on the Chessboard distance function could segment specific objects successfully for all grayscale images with the fastest execution time as compared to other models.

Selective Image Segmentation Models Using Three Distance Functions

Image segmentation can be defined as partitioning an image that contains multiple segments of meaningful parts for further processing. Global segmentation is concerned with segmenting the whole object of an observed image. Meanwhile, the selective segmentation model is focused on segmenting a specific object required to be extracted. The Convex Distance Selective Segmentation (CDSS) model, which uses the Euclidean distance function as the fitting term, was proposed in 2015. However, the Euclidean distance function takes time to compute. This paper proposed the reformulation of the CDSS minimization problem by changing the fitting term with three popular distance functions, namely Chessboard, City Block, and Quasi-Euclidean. The proposed models were CDSSNEW1, CDSSNEW2, and CDSSNEW3, which applied the Chessboard, City Block, and Quasi-Euclidean distance functions, respectively. In this study, the Euler-Lagrange (EL) equations of the proposed models were derived and solved using the Additive Operator Splitting method. Then, MATLAB coding was developed to implement the proposed models. The accuracy of the segmented image was evaluated using the Jaccard and Dice Similarity Coefficients. The execution time was recorded to measure the efficiency of the models. Numerical results showed that the proposed CDSSNEW1 model based on the Chessboard distance function could segment specific objects successfully for all grayscale images with the fastest execution time as compared to other models.

From 2D and 3D documentation to 4D interpretation. Building archaeological conclusions and workflow strategies gained by remote study of Insula V 1, Pompeii

The text describes new methods elaborated for and used in the building archaeological assessment of a city block, studied first on site, then remotely by members of the Swedish Pompeii Project. Use of a digital platform, with collected wall observations and analysis, systematic photographic documentation of all standing structures, and 3D models, allowed discussion to proceed after the fieldwork came to an end. The models provided new possibilities and new angles of approach, e.g. examining walls at any given point, studying boundary walls as wall-strings in their full extent, allowing all kinds of sectioning at will, introducing bird’s-eye views as a new perspective in study, and measuring wherever needed. The joint results obtained are summed up in a four-phase development of the use of space: the earliest structures; the late Samnite building boom (2nd century BC); the colony (second half of 1st century BC); the imperial era (until AD 79). This narrative includes conclusions concerning building process and development of masonry techniques and on changes in way of life. Many results affect Pompeian archaeology in general. Results of particular importance concern the character of the early plot division and the understanding of the building process creating the double-atrium house of Caecilius Iucundus, including an anchorage in time for this creation in the Claudian period. The relatively small impact in terms of damage that may be ascribed the literary recorded earthquake of AD 62/63 is also worth noting. The text ends with a suggestion of a new workflow for insula studies.

How Do Two- and Three-Dimensional Urban Structures Impact Seasonal Land Surface Temperatures at Various Spatial Scales? A Case Study for the Northern Part of Brooklyn, New York, USA

Identifying the driving factors of urban land surface temperatures (U-LSTs) is critical in improving urban thermal environments and in supporting the sustainable development of cities. Previous studies have demonstrated that two- and three-dimensional (2D and 3D) urban structure parameters (USPs) largely influence seasonal U-LSTs. However, the effects of 2D and 3D USPs on seasonal U-LSTs at different spatial scales still await a general explanation. In this study, we used very-high-resolution remotely sensed data to investigate how 2D and 3D USPs impact seasonal U-LSTs at different spatial scales (including pixel and city block scales). In addition, the influences of various functional zones on U-LSTs were analyzed. The results show that, (1) generally, the links between USPs and U-LSTs at the city block scale were more obvious than those at the pixel scale, e.g., the Pearson correlation coefficient (r) between U-LST and the mean building height at the city block scale (summer: r = −0.156) was higher than that at the pixel scale (summer: r = −0.081). Tree percentage yielded a considerable cooling effect on summer U-LSTs on both the pixel (r = −0.199) and city block (r = −0.369) scales, and the effect was more obvious in regions with tall trees. (2) The independently total explained variances (R2) of 3D USPs on seasonal U-LSTs were considerably higher than those of 2D USPs in most urban functional zones (UFZs), suggesting the distinctive roles of 3D USPs in U-LST regulation at the local scale. Three-dimensional USPs (R2 value = 0.66) yielded more decisive influences on summer U-LSTs than 2D USPs did (R2 value = 0.48). (3) Manufacturing zones yielded the highest U-LST, followed by residential and commercial zones. Notably, it is found that the explained variances of the total study area for seasonal U-LSTs were significantly lower than those of each UFZ, suggesting the different roles of 2D and 3D USPs played in various UFZs and that it is critical to explain U-LST variations by using UFZs.

Homoclimate of Iceland’s meteorological stations for comparison with the homoclimate of some northern countries

In many fields including agroclimatology, pedology, plant introduction, environmental health and agricultural transfer, detection of areas of similar climate is of significant interest. Numerical methods including cluster analysis, similarity measures, and other techniques were used to compare climatic data from Islandian meteorological stations to classify them according to similar homoclimate. Using Euclidean distance and City-block (Manhattan) distance, data from Iceland, Finland, Sweden, Norway, and Alaska state of the USA were analyzed to reveal homoclime. One of the conclusions from the study is that Iceland has a similar climate to Alaska and Norway. Climate change is already affecting agriculture, with effects unevenly distributed across the world. These changes will undoubtedly lead to a reconsideration of the question of allocation of appropriate agricultural crops to given areas and evaluation of bioclimatic resources in territories with similar climate. Results from this study are related to the territory of Iceland, but the approach to classify meteorological stations according to similar homoclimate and reveal homoclime in selected territories is applicable everywhere in the world.