【正文】 can be searchable, while text information inside the raster file bees integrated into the image and is no longer recognized as text. SVG is also particularly suitable for displaying intelligent maps, because geometric objects such as points, lines, and polygons are recognized as such and are identifiable. Raster images on the other hand contain information about every pixel, and points, lines and polygons that are no longer recognizable. Therefore, the user can directly work with spatial features on an SVG but not on a raster graphic image (Peng and Zhang, 2021). SVG is also based on XML and therefore conforms to other XMLbased standards and technologies, such as XML Namespace, XLink, and XPointer. XLink and XPointer allow for linking from within SVG files to other files on the Web, like a GML data element, HTML pages or other SVG files (Boye, 1999). . Extensible stylesheet language transformation—XSLT XSLT is a language that enables the user to convert XML documents into other XML documents or into almost any form an application or a user needs. XSLT provides an easy, W3C sanctioned, way to convert XML documents that conform to a schema into documents that conform to another, enabling the sharing of information between different systems. From another perspective XSLT is a programming language that describes the way and the methods to be followed for the transformation of a wellformed tree structure of an XML document to another. XSLT is not the only way to achieve these goals。 Raster image encoding。 The potential of XML encoding in geomatics converting raster images to XML and SVG Byron Antoniou, Lysandros Tsoulos Abstract The evolution of open standards and especially those pertaining to the family of XML technologies, have a considerable impact on the way the Geomatics munity addresses the acquisition, storage, analysis and display of spatial data. The most recent version of the GML specification enables the merging of vector and raster data into a single ‘‘open’’ format. The notion of ‘‘coverage’’ as described in GML can be the equivalent of a raster multiband dataset. In addition, vector data storage is also described in detail through the GML Schemas and XML itself can store the values of a raster dataset, as values of a multitable dataset. Under these circumstances an issue that must be addressed is the transformation of raster data into XML format and their subsequent visualization through SVG. The objective of this paper is to give an overview of the steps that can be followed in order to embody open standards and XML technologies in the raster domain. The last part of the work refers to a case study that suggests a step by step methodology to acplish classification, an important function in Cartography and Remote Sensing, using the XMLencoded images. 169。 2021 Elsevier Ltd. All rights reserved. Keywords: Open standards。 Classification The advent of XMLbased technologies has gone beyond the expectations of the most optimistic users. Revolutionary ideas are emerging for the storage, exchange and display of data and new formats are created for almost all kinds of data, applications and knowledge domains. A considerable number of specifications have been issued by international anizations aiming at the provision of an efficient ‘‘open’’ environment to the user munity. Watching this frenzy trend of transforming everything into XMLbased structures, one thing seems really out of the way: raster images. Languages like HTML and SVG do not have such a structural feature in their environment. Instead, both of them provide means (., img or image elements) for the incorporation of raster images in textbased files, usually with an inline reference. The existing specifications instead of dealing with the problem bypass it and users treat raster formats more or less like a requisite tool for their work. The truth is that there is nothing mon between XMLbased structures and raster images. Raster image encoding is neither text based nor human readable and it cannot be parsed, checked for validity or well formedness. Moreover, the raster image content has almost no flexibility (apart from resizing) in an XMLbased environment, since pixel values are well locked inside the raster formats (Antoniou and Tsoulos, 2021). Converting a raster formatted image into XML enables the user to utilize the information residing in the image and select, read and manipulate the parts of the XML file or the file as a whole in a number of ways in accordance with the application at hand. This is the starting point for classification, statistical processing, filtering or the development of other applications with the use of XML technology. Operations like the storage and exchange of images acquire a new meaning in the framework of an interoperable environment like WebGIS. Converting an image from raster to SVG is even more exciting. An SVGencoded image file enjoys all the abovementioned advantages。 there are alternative ways to transform XML documents but XSLT has prevailed. The fact that XSLT is a W3C standard implies that XSLT plies with the specifications published by the W3C or those that will be announced in the future (Clark, 1999). Furthermore, the nonproprietary status of the specification and the platform independency, guarantee the prospects and the integrity of the specification. In addition, the fact that the XSLT document transformation instructions are stored as an XML document is an advantage since there is no need for using another syntax. The abovementioned characteristics justify the popularity of XSLT when it es to XML transformation (DuCharme, 2021). . Data model encoding The accurate representation of the plexity of the real world has bee