Pub Date : 2021-11-10DOI: 10.1080/15230406.2021.1991478
Xiao-Jiao Huo, Chen Zhou, Yunyun Xu, Manchun Li
ABSTRACT Polygon-to-raster conversion inevitably introduces a loss in spatial properties of polygons, such as area or topology, which should be preserved. Existing methods preserve only one property, resulting in greater losses in other properties. In this study, we propose a new methodology to balance the preservation of area, shape, and topological properties during conversion. By reassigning cells of the rasterized outcome, the method first compensates for the loss in shape properties. Topological changes are then corrected by comparing the topological relations of raster regions and their corresponding polygons. Finally, the areas between pairs of neighboring regions are coordinated to maintain area properties. The main contribution of this study relies on the fact that the presented method considers the interactions of different properties, rather than separately preserving each of them. We employed a land-use dataset containing 14,000 polygons for our experiments. When the cell size increased from 5 to 25 m, the presented method resolved 48.4% of overall rasterization errors on average, which was much higher than those of the area-, shape-, and topology-preserving methods (i.e. 2.6%, 26.7%, and 34./0%, respectively). However, the presented method increased the computational time by 579%, 264%, and 52%, respectively, as compared with these three methods.
{"title":"A methodology for balancing the preservation of area, shape, and topological properties in polygon-to-raster conversion","authors":"Xiao-Jiao Huo, Chen Zhou, Yunyun Xu, Manchun Li","doi":"10.1080/15230406.2021.1991478","DOIUrl":"https://doi.org/10.1080/15230406.2021.1991478","url":null,"abstract":"ABSTRACT Polygon-to-raster conversion inevitably introduces a loss in spatial properties of polygons, such as area or topology, which should be preserved. Existing methods preserve only one property, resulting in greater losses in other properties. In this study, we propose a new methodology to balance the preservation of area, shape, and topological properties during conversion. By reassigning cells of the rasterized outcome, the method first compensates for the loss in shape properties. Topological changes are then corrected by comparing the topological relations of raster regions and their corresponding polygons. Finally, the areas between pairs of neighboring regions are coordinated to maintain area properties. The main contribution of this study relies on the fact that the presented method considers the interactions of different properties, rather than separately preserving each of them. We employed a land-use dataset containing 14,000 polygons for our experiments. When the cell size increased from 5 to 25 m, the presented method resolved 48.4% of overall rasterization errors on average, which was much higher than those of the area-, shape-, and topology-preserving methods (i.e. 2.6%, 26.7%, and 34./0%, respectively). However, the presented method increased the computational time by 579%, 264%, and 52%, respectively, as compared with these three methods.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"49 1","pages":"115 - 133"},"PeriodicalIF":2.5,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44146267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-10DOI: 10.1080/15230406.2021.1982009
Mingguang Wu, Yanjie Sun, Yaqian Li
ABSTRACT Because crafting attractive and effective colors from scratch is a high-effort and time-consuming process in map and visualization design, transferring color from an inspiration source to maps and visualizations is a promising technique for both novices and experts. To date, existing image-to-image color transfer methods suffer from ambiguities and inconsistencies; no computational approach is available to transfer color from arbitrary images to vector maps. To fill this gap, we propose a computational method that transfers color from arbitrary images to a vector map. First, we classify reference images into regions with measures of saliency. Second, we quantify the communicative quality and esthetics of colors in maps; we then transform the problem of color transfer into a dual-objective, multiple-constraint optimization problem. We also present a solution method that can create a series of optimal color suggestions and generate a communicative quality-esthetic compromise solution. We compare our method with an image-to-image method based on two sample maps and six reference images. The results indicate that our method is adaptive to mapping scales, themes, and regions. The evaluation also provides preliminary evidence that our method can achieve better communicative quality and harmony.
{"title":"Adaptive transfer of color from images to maps and visualizations","authors":"Mingguang Wu, Yanjie Sun, Yaqian Li","doi":"10.1080/15230406.2021.1982009","DOIUrl":"https://doi.org/10.1080/15230406.2021.1982009","url":null,"abstract":"ABSTRACT Because crafting attractive and effective colors from scratch is a high-effort and time-consuming process in map and visualization design, transferring color from an inspiration source to maps and visualizations is a promising technique for both novices and experts. To date, existing image-to-image color transfer methods suffer from ambiguities and inconsistencies; no computational approach is available to transfer color from arbitrary images to vector maps. To fill this gap, we propose a computational method that transfers color from arbitrary images to a vector map. First, we classify reference images into regions with measures of saliency. Second, we quantify the communicative quality and esthetics of colors in maps; we then transform the problem of color transfer into a dual-objective, multiple-constraint optimization problem. We also present a solution method that can create a series of optimal color suggestions and generate a communicative quality-esthetic compromise solution. We compare our method with an image-to-image method based on two sample maps and six reference images. The results indicate that our method is adaptive to mapping scales, themes, and regions. The evaluation also provides preliminary evidence that our method can achieve better communicative quality and harmony.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"49 1","pages":"289 - 312"},"PeriodicalIF":2.5,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45006531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-02DOI: 10.1080/15230406.2021.1965915
Qingsong Liu, Mengmeng Liu, X. Ye
ABSTRACT The Segregation Index quantifies the degree of segregation of social groups or classes. Because of the increasing use of fine-grained spatiotemporal activity and flow data, the conventional segregation measurements’ inclusiveness is challenged. We add population flow to the conventional place-based spatial exposure index to identify spatiotemporal segregation changes. Specifically, we considered the population-flow network, hierarchical structure, and time. In Chicago’s demonstration case study, we first used the time-dependent Twitter Origin-Destination flow matrices and their hierarchical structure information to estimate interactions between areal units at the neighborhood level. Then we computed the new population composition of units based on their interactions with other units and estimated the proposed spatiotemporal exposure index for different times. Finally, we systematically compared their differences with the conventional indices at global and local scales to see how population-flow patterns affect the exposure index. The results show that the population-flow patterns reflect valuable information in neighborhood interactions in temporal and spatial dimensions, but it is missing information in the conventional segregation computations. Furthermore, we emphasize that the hierarchical structures of flow patterns and the choice of appropriate parameters are also important factors for a rational segregation evaluation.
{"title":"An extended spatiotemporal exposure index for urban racial segregation","authors":"Qingsong Liu, Mengmeng Liu, X. Ye","doi":"10.1080/15230406.2021.1965915","DOIUrl":"https://doi.org/10.1080/15230406.2021.1965915","url":null,"abstract":"ABSTRACT The Segregation Index quantifies the degree of segregation of social groups or classes. Because of the increasing use of fine-grained spatiotemporal activity and flow data, the conventional segregation measurements’ inclusiveness is challenged. We add population flow to the conventional place-based spatial exposure index to identify spatiotemporal segregation changes. Specifically, we considered the population-flow network, hierarchical structure, and time. In Chicago’s demonstration case study, we first used the time-dependent Twitter Origin-Destination flow matrices and their hierarchical structure information to estimate interactions between areal units at the neighborhood level. Then we computed the new population composition of units based on their interactions with other units and estimated the proposed spatiotemporal exposure index for different times. Finally, we systematically compared their differences with the conventional indices at global and local scales to see how population-flow patterns affect the exposure index. The results show that the population-flow patterns reflect valuable information in neighborhood interactions in temporal and spatial dimensions, but it is missing information in the conventional segregation computations. Furthermore, we emphasize that the hierarchical structures of flow patterns and the choice of appropriate parameters are also important factors for a rational segregation evaluation.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"48 1","pages":"530 - 545"},"PeriodicalIF":2.5,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46344262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-02DOI: 10.1080/15230406.2021.1952109
L. VILCHES-BLÁZQUEZ, José Ángel Ramos
ABSTRACT Manifold providers from a wide range of initiatives (private organizations, volunteered efforts, social media, etc.) offer enormous data amounts with geospatial characteristics. These efforts of many data providers entail multiple data scenarios and imply many viewpoints about the same feature, involving different representations, accuracy, models, vocabularies, etc. Various techniques or processes are employed to deal with these heterogeneity problems related to diverse data sources within the conflation research area. However, semantic conflation has not been addressed widely in the literature, unlike geometrical conflation. Hence, it is unclear what issues semantic conflation tries to solve and what activities, methods, metrics, and techniques have been used in existing GIScience investigations. In this article, we carry out a systematic review of approaches that focus on semantic aspects for geospatial data conflation. Besides, we analyze a wide selection of contributions following different criteria to depict a detailed semantic conflation status in GIScience. Our contributions are: (i) an overview of semantic conflation application domains, (ii) a characterization of semantic issues within these domains, (iii) the recognition of gaps and weaknesses of collected researches, and (iv) several open challenges and opportunities for next steps in this GIScience research area.
{"title":"Semantic conflation in GIScience: a systematic review","authors":"L. VILCHES-BLÁZQUEZ, José Ángel Ramos","doi":"10.1080/15230406.2021.1952109","DOIUrl":"https://doi.org/10.1080/15230406.2021.1952109","url":null,"abstract":"ABSTRACT Manifold providers from a wide range of initiatives (private organizations, volunteered efforts, social media, etc.) offer enormous data amounts with geospatial characteristics. These efforts of many data providers entail multiple data scenarios and imply many viewpoints about the same feature, involving different representations, accuracy, models, vocabularies, etc. Various techniques or processes are employed to deal with these heterogeneity problems related to diverse data sources within the conflation research area. However, semantic conflation has not been addressed widely in the literature, unlike geometrical conflation. Hence, it is unclear what issues semantic conflation tries to solve and what activities, methods, metrics, and techniques have been used in existing GIScience investigations. In this article, we carry out a systematic review of approaches that focus on semantic aspects for geospatial data conflation. Besides, we analyze a wide selection of contributions following different criteria to depict a detailed semantic conflation status in GIScience. Our contributions are: (i) an overview of semantic conflation application domains, (ii) a characterization of semantic issues within these domains, (iii) the recognition of gaps and weaknesses of collected researches, and (iv) several open challenges and opportunities for next steps in this GIScience research area.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"48 1","pages":"512 - 529"},"PeriodicalIF":2.5,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46802045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-28DOI: 10.1080/15230406.2021.1983731
Haosheng Huang, Thomas Mathis, R. Weibel
ABSTRACT State-of-the-art mobile pedestrian navigation systems often employ GPS or other positioning methods for continuous tracking of users, and thus provide them with in-situ turn-by-turn route guidance along a desired route. However, studies have shown that user experience and acquisition of spatial knowledge decrease due to the “blind” following of such turn-by-turn navigation systems. This paper proposes a novel interface concept for mobile pedestrian navigation systems that provide navigation guidance without restricting the users to a predefined route. Specifically, the proposed novel user interface was based on the concept of the Potential Route Area (PRA), which defines a dynamic area consisting of all potential routes not longer than a certain detour the user is willing to accept. Within that area, the user can freely choose his/her own route and alter it anytime, and can still arrive at the destination within the desired detour tolerance. As a proof of concept, the proposed PRA-based system was then tested against a conventional turn-by-turn navigation system, represented by Google Maps, in a real-world navigation experiment, which revealed that the acquisition of spatial knowledge and user experience were substantially improved when using the PRA-based system. This can be explained by the fact that the PRA-based system provides its users with more freedom in choosing their own route.
{"title":"Choose your own route – supporting pedestrian navigation without restricting the user to a predefined route","authors":"Haosheng Huang, Thomas Mathis, R. Weibel","doi":"10.1080/15230406.2021.1983731","DOIUrl":"https://doi.org/10.1080/15230406.2021.1983731","url":null,"abstract":"ABSTRACT State-of-the-art mobile pedestrian navigation systems often employ GPS or other positioning methods for continuous tracking of users, and thus provide them with in-situ turn-by-turn route guidance along a desired route. However, studies have shown that user experience and acquisition of spatial knowledge decrease due to the “blind” following of such turn-by-turn navigation systems. This paper proposes a novel interface concept for mobile pedestrian navigation systems that provide navigation guidance without restricting the users to a predefined route. Specifically, the proposed novel user interface was based on the concept of the Potential Route Area (PRA), which defines a dynamic area consisting of all potential routes not longer than a certain detour the user is willing to accept. Within that area, the user can freely choose his/her own route and alter it anytime, and can still arrive at the destination within the desired detour tolerance. As a proof of concept, the proposed PRA-based system was then tested against a conventional turn-by-turn navigation system, represented by Google Maps, in a real-world navigation experiment, which revealed that the acquisition of spatial knowledge and user experience were substantially improved when using the PRA-based system. This can be explained by the fact that the PRA-based system provides its users with more freedom in choosing their own route.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"49 1","pages":"95 - 114"},"PeriodicalIF":2.5,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44355827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-06DOI: 10.1080/15230406.2021.1980435
Hua Liao, Weihua Dong, Zhicheng Zhan
ABSTRACT Individuals with different characteristics exhibit different eye movement patterns in map reading and wayfinding tasks. In this study, we aim to explore whether and to what extent map users’ eye movements can be used to detect who created them. Specifically, we focus on the use of gaze data for inferring users’ identities when users are performing map-based spatial tasks. We collected 32 participants’ eye movement data as they utilized maps to complete a series of self-localization and spatial orientation tasks. We extracted five sets of eye movement features and trained a random forest classifier. We used a leave-one-task-out approach to cross-validate the classifier and achieved the best identification rate of 89%, with a 2.7% equal error rate. This result is among the best performances reported in eye movement user identification studies. We evaluated the feature importance and found that basic statistical features (e.g. pupil size, saccade latency and fixation dispersion) yielded better performance than other feature sets (e.g. spatial fixation densities, saccade directions and saccade encodings). The results open the potential to develop personalized and adaptive gaze-based map interactions but also raise concerns about user privacy protection in data sharing and gaze-based geoapplications.
{"title":"Identifying map users with eye movement data from map-based spatial tasks: user privacy concerns","authors":"Hua Liao, Weihua Dong, Zhicheng Zhan","doi":"10.1080/15230406.2021.1980435","DOIUrl":"https://doi.org/10.1080/15230406.2021.1980435","url":null,"abstract":"ABSTRACT Individuals with different characteristics exhibit different eye movement patterns in map reading and wayfinding tasks. In this study, we aim to explore whether and to what extent map users’ eye movements can be used to detect who created them. Specifically, we focus on the use of gaze data for inferring users’ identities when users are performing map-based spatial tasks. We collected 32 participants’ eye movement data as they utilized maps to complete a series of self-localization and spatial orientation tasks. We extracted five sets of eye movement features and trained a random forest classifier. We used a leave-one-task-out approach to cross-validate the classifier and achieved the best identification rate of 89%, with a 2.7% equal error rate. This result is among the best performances reported in eye movement user identification studies. We evaluated the feature importance and found that basic statistical features (e.g. pupil size, saccade latency and fixation dispersion) yielded better performance than other feature sets (e.g. spatial fixation densities, saccade directions and saccade encodings). The results open the potential to develop personalized and adaptive gaze-based map interactions but also raise concerns about user privacy protection in data sharing and gaze-based geoapplications.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"49 1","pages":"50 - 69"},"PeriodicalIF":2.5,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48649096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-29DOI: 10.1080/15230406.2021.1975571
Brenton R. S. Recht
ABSTRACT We present a variation on the Chamberlin trimetric map projection. This new projection, which we call the matrix trimetric projection, consists of a linear transformation of the squares of the distances between a given point and three control points. The formula of the forward projection is simpler than the Chamberlin projection, and admits an inverse formula which requires numerical iteration of only one parameter. We make comparisons between the two projections using a representative list of control points. The Chamberlin trimetric projection outperforms the matrix trimetric projection on measures of angle deformation and area deformation, but the opposite is true for a measure of distance deformation, and the difference between the results of the projections is small over all measures. The forward Matrix trimetric projection can be calculated in half the time of the Chamberlin trimetric projection. We conclude that the matrix trimetric projection is a viable alternative to the Chamberlin trimetric projection, especially if an inverse is required or speed is important.
{"title":"A variation on the Chamberlin trimetric map projection","authors":"Brenton R. S. Recht","doi":"10.1080/15230406.2021.1975571","DOIUrl":"https://doi.org/10.1080/15230406.2021.1975571","url":null,"abstract":"ABSTRACT We present a variation on the Chamberlin trimetric map projection. This new projection, which we call the matrix trimetric projection, consists of a linear transformation of the squares of the distances between a given point and three control points. The formula of the forward projection is simpler than the Chamberlin projection, and admits an inverse formula which requires numerical iteration of only one parameter. We make comparisons between the two projections using a representative list of control points. The Chamberlin trimetric projection outperforms the matrix trimetric projection on measures of angle deformation and area deformation, but the opposite is true for a measure of distance deformation, and the difference between the results of the projections is small over all measures. The forward Matrix trimetric projection can be calculated in half the time of the Chamberlin trimetric projection. We conclude that the matrix trimetric projection is a viable alternative to the Chamberlin trimetric projection, especially if an inverse is required or speed is important.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"49 1","pages":"85 - 94"},"PeriodicalIF":2.5,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46505471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-03DOI: 10.1080/15230406.2021.1942218
V. Vlad, M. Toti, S. Dumitru, C. Simota, M. Dumitru
ABSTRACT The legends of natural resource taxonomy-based maps (e.g. soil, geological, geomorphological, vegetation, and land cover/land use) need many different distinguishable colors. The existing methods of color selection for map legends are based on the designer subjectivity, ensuring schemes having few colors. An analysis of the modeling and management of colors in digital applications has led to define an algorithm to calculate an objective colorimetric measure of color difference – “DE*ab ” – based on the perceptually uniform color model CIELAB. The proposed method consists of a set of specific rules for developing hierarchically structured color schemes and a specific procedure for ensuring selection of a large number of reliably distinguishable colors, based on a color difference threshold. The accuracy of color reproduction in printing processes is also taken into account. The method has been applied to develop a standard of colors for soil maps. It contains 63 colors and has been used for developing a soil map having 41 standard colors. A user test of the method results proved that thresholds of 10 DE*ab units and 15 DE*ab units ensure obtaining acceptably distinguishable colors for displaying/printing maps by using high-quality, respectively, current devices. Three datasets that support the research are given.
{"title":"Developing reliably distinguishable color schemes for legends of natural resource taxonomy-based maps","authors":"V. Vlad, M. Toti, S. Dumitru, C. Simota, M. Dumitru","doi":"10.1080/15230406.2021.1942218","DOIUrl":"https://doi.org/10.1080/15230406.2021.1942218","url":null,"abstract":"ABSTRACT The legends of natural resource taxonomy-based maps (e.g. soil, geological, geomorphological, vegetation, and land cover/land use) need many different distinguishable colors. The existing methods of color selection for map legends are based on the designer subjectivity, ensuring schemes having few colors. An analysis of the modeling and management of colors in digital applications has led to define an algorithm to calculate an objective colorimetric measure of color difference – “DE*ab ” – based on the perceptually uniform color model CIELAB. The proposed method consists of a set of specific rules for developing hierarchically structured color schemes and a specific procedure for ensuring selection of a large number of reliably distinguishable colors, based on a color difference threshold. The accuracy of color reproduction in printing processes is also taken into account. The method has been applied to develop a standard of colors for soil maps. It contains 63 colors and has been used for developing a soil map having 41 standard colors. A user test of the method results proved that thresholds of 10 DE*ab units and 15 DE*ab units ensure obtaining acceptably distinguishable colors for displaying/printing maps by using high-quality, respectively, current devices. Three datasets that support the research are given.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"48 1","pages":"393 - 416"},"PeriodicalIF":2.5,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48868364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-03DOI: 10.1080/15230406.2021.1936184
Taisheng Chen, Menglin Chen, A. Zhu, Weixing Jiang
ABSTRACT Color quality evaluation is key to judging map quality, which can improve data visualization and communication. However, most existing methods for evaluating map colors are tedious and subjective manual methods. In this paper, we study sequential color schemes, a widely used map color type and propose a learning-based approach for evaluating the color quality. The approach consists of two steps. First, we extract and characterize the cartographic factors for determining the quality of sequential color schemes, such as color order, color match, color harmony, color discrimination and color uniformity. Second, we present a model to predict the color quality based on AdaBoost, a type of ensemble learning algorithm with excellent classification performance and use these factors as input data. We conduct a case study based on 781 samples and train the AdaBoost-based model to predict the quality of sequential color schemes. To evaluate the model’s performance, we calculated the area under the receiver operating characteristic (ROC) curve (AUC). The AUC values are 0.983 and 0.977 on the training data and testing data, respectively. These results indicate that the proposed approach can be used to automatically evaluate the quality of sequential color schemes for maps, which helps mapmakers select good colors.
{"title":"A learning-based approach to automatically evaluate the quality of sequential color schemes for maps","authors":"Taisheng Chen, Menglin Chen, A. Zhu, Weixing Jiang","doi":"10.1080/15230406.2021.1936184","DOIUrl":"https://doi.org/10.1080/15230406.2021.1936184","url":null,"abstract":"ABSTRACT Color quality evaluation is key to judging map quality, which can improve data visualization and communication. However, most existing methods for evaluating map colors are tedious and subjective manual methods. In this paper, we study sequential color schemes, a widely used map color type and propose a learning-based approach for evaluating the color quality. The approach consists of two steps. First, we extract and characterize the cartographic factors for determining the quality of sequential color schemes, such as color order, color match, color harmony, color discrimination and color uniformity. Second, we present a model to predict the color quality based on AdaBoost, a type of ensemble learning algorithm with excellent classification performance and use these factors as input data. We conduct a case study based on 781 samples and train the AdaBoost-based model to predict the quality of sequential color schemes. To evaluate the model’s performance, we calculated the area under the receiver operating characteristic (ROC) curve (AUC). The AUC values are 0.983 and 0.977 on the training data and testing data, respectively. These results indicate that the proposed approach can be used to automatically evaluate the quality of sequential color schemes for maps, which helps mapmakers select good colors.","PeriodicalId":47562,"journal":{"name":"Cartography and Geographic Information Science","volume":"48 1","pages":"377 - 392"},"PeriodicalIF":2.5,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15230406.2021.1936184","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42862081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/15230406.2021.1966648
Mingke Li, H. McGrath, E. Stefanakis
ABSTRACT The Canadian Digital Elevation Model (CDEM) and the High-Resolution Digital Elevation Model (HRDEM) released by Natural Resources Canada are primary terrain data sources in Canada. Due to their different coverage, datums, resolutions, and accuracies, a standardized framework for national elevation data across various scales is required. This study provides new insights into the adoption of Discrete Global Grid Systems (DGGS) to facilitate the integration of multi-source terrain data at various granularities. In particular, the Icosahedral Snyder Equal Area Aperture 3 Hexagonal Grid (ISEA3H) was employed, and quantization, integration, and aggregation were conducted on this framework. To demonstrate the modeling process, an experiment was undertaken for two areas in Ontario, taking advantage of parallel computing which was beneficial from the discreteness of DGGS cells. The accuracy of the modeled elevations was estimated by referring to the ground-surveyed values and was included in the spatially referenced metadata as an indicator of data quality. This research can serve as a guide for future development of a national elevation service, providing consistent, multi-resolution elevations and avoiding complex, duplicated pre-processing at the user’s end. Future investigation into an operational integration platform to support real-world decision-making, as well as the DGGS-powered geospatial datacube, is recommended.
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