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Recent years have witnessed a dynamic development of web place locators and web mapping services. Google Maps is currently the most popular and most advanced web mapping service. The paper presents the analysis and description of the ability of the Google Maps programming interface to visualize digital orthophotomaps and describes an application named Orthophoto, which processes digital orthophotomaps, and the development of a web site that allows such maps to be visualized in the Google Maps service. The operation of the Orthophoto application and the web page was tested on both color and black-and-white digital orthophotomaps covering four communes in the Pisz district. The orthophothomaps were prepared with georeferences in the 1:5000 scale and fitted into the geodesic coordinate systems of 1965 and 2000. The Orthophoto application was developed in the object-oriented programming language Java, in environment NetBeans IDE 6.0. The software processes orthophotomap into a pyramid of images with 9 levels, divided into basic elements, the so called tiles (resolution 256 × 256 pixels) with zoom 10÷18, written in the PNG format in separate graphic files. The name of each tile contains the scale and position of an element on a map. The Orthophoto software provides formulas for transformation of geodetic coordinates from systems 1965 and 2000 into geodetic coordinates B, L on the ellipsoid GRS-80. The web application, developed in HTML language with elements of JavaScript language, enables viewing of the processed orthophotomap in the form of tiles against the background of data collected from the Google Maps service. It ensures continuity and smoothness of the visualization. The application benefits from the functionality of the Google Maps programming interface – active controls enable navigating through a map and changing the zoom. The advantage of the application derives from the ability of digital processing and visualization in the Google Maps service of any image data available to an individual user, including orthoimages, large-scale digital orthophotomaps, etc.
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