RasterView is a CUPS raster file viewer for CUPS 1.2 and higher. It basically allows you to look at the raster data produced by any of the standard CUPS RIP filters (imagetoraster and pstoraster are used on all platforms; cgimagetoraster and cgpdftoraster are used on Mac OS X). RasterView is useful to either test those filters without a printer, or look at the data that is being sent to your raster printer driver.