A raster generation system for a printing machine with an image-setting unit in which the system has at least one raster processor for generating raster data from raw image data, and a memory for storing the raster data. In order to have a raster generation system with a high operating speed in spite of the simple components that are used, the memory for storing the raster data is formed by a raster memory with random access, and the raster processor stores the raster data column by column in the raster memory.