RSVG:Displaying Big Size Vector Map on Mobile Devices

Abstract

In resource-constrained environment such as low-end-mobile, the challenges faced are mainly the memory and the processing capacities limitations, and the bandwidth rate. Many works tried to overcome them; yet, the need of intelligent applications is required to enhance the devices speed in many ways. For the display systems of the handheld devices, besides the listed constraints one needs to take in consideration the screen size. Displaying Geographical Information (GIS) data such as Maps on these devices is very demanding in terms of processing and memory and requires a reliable strong bandwidth. On one hand, for convenience reason, mobile devices are commonly used for displaying GIS data. On the other hand, maps have become more complex so that it is challenging to load an entire map on de client and render at once. To this end, this thesis presents a model for displaying big size vector maps on handheld devices. We propose in the server side, an Rsvg concept through a data structure for maps organization. In the client side, we present an event-driven Level Of Details (LOD) for the defined data structure and a reduction of the waiting time while a zooming event required downloading from the server. This model is then applied in the evaluation of the Scalable Vector Graphics (SVG) of the World Wide Web Consortium (W3C). While rendering big files in the traditional SVG display is impossible in mobile client, Rsvg experiments demonstrated better results through the progressive transmission, based on the breadth first tree traversal algorithm.