Changes of Image Server from #3 to #4

11: 1 Specification

12: 1.1 Behaviour

13: 1.1.1 Request

14: A picture is requested with an picture name and a bounding box. The bounding box specifies the maximal size of the image. The Image Server has a configured raster in which it provides pictures. Lets assume the raster is set to 50 pixel. The picture size is scaled down to fit in the bounding box and then the width is rounded down multiple of 50. (The height is obviously scaled down as well) The needed version of the picture is looked up in the cache and is generated if needed. The file name contains the dimensions and the request is answered using redirection to that file. That allows browser side caching even for slightly different bounding boxes.

15: 1.1 Interface