Hi! I have recently installed ms4w 2.2.6 beta which include MS 5.0 RC2. The reason for this was to test the new AGG rendering engine when using Mapserver as a WMS server, with only high resolution (RGB) rasters as the data source. Most WMS servers around (both free and commercial) uses nearest neighbor interpolation on the resulting image that is transfered to the client. In situations where the source data is only hires rasters or imagery (as in my case), the quality of the output would be much better if you could apply an bilinear interpolation to the produced image (see the attached images for an example). Because in most cases the pixels in the source data and the pixels on the screen do not match up, even if I have produces pyramids on the source data (using gdal gdaladdo with the average option sett). The only WMS servers that has the ability to interpolate the resulting image with bilinear interpolation (that I have discovered) is the ESRI ArcIMS ArcMap image service and the ESRI ArcGIS Server.
I kind of hoped that the new AGG rendering back-end would give an option to set the interpolation method used in the output, but I see no difference when using AGG instead of GD. (IMAGEMODE is 24bit (RGB) PNG in both cases). Am I missing something here, or do not AGG increase the image quality if the resulting image if the data source is only rasters? Does anyone have any experience concerning this issue, and maybe could give me some advice? ArcGIS Server http://www.nabble.com/file/p12754990/ArcGIS_Server.png Mapserver 5.0 rc2 with AGG rendering http://www.nabble.com/file/p12754990/MapServer_5rc2_AGG.png Regards, Pål Kristensen Norwegian Mapping and Cadastre Authority -- View this message in context: http://www.nabble.com/Interpolate-image-tf4473610.html#a12754990 Sent from the Mapserver - User mailing list archive at Nabble.com.
