Design Of Picture Viewer Software In GPS Navigation Device Based On S3C2440

Nowadays, most digital products have picture viewer. The picture viewer designed in this thesis is an indispensable part of GPS navigation device based on S3C2440.The picture viewer consists of three modules, which are display module, function module and loading picture list module. Display module concludes displaying 24 bits bitmap and displaying JPEG picture. Function module is made of playing picture automatically, revolving picture, magnifying picture, minifying picture, loading picture, unloading picture, looking at previous picture, looking at next picture and quitting software. As for revolving picture, other designers usually copy pixels between two device contexts. So revolving picture is very slow. To solve this problem, the thesis adopts a mechanism of assigning the memory previously. Its basic idea is to store the picture in the memory assigned previously after the picture is revolved, then to display it. Loading picture list module is run by loading function. Every item in picture list consists of picture name and picture path.In this thesis, we firstly introduce the project background of this design. Secondly, we give the hardware platform of picture viewer. Thirdly, we analyze the .bmp format, the .jpg format, and corresponding decoding method. Then, we expound how to realize the basic function in every module of picture viewer. Lastly, we point out the shortage of our picture viewer, and the direction of improving.