Abstract: Embodiments of the present invention are directed to a microcontroller system incorporating a DMA system and to a method of accessing a memory by a plurality of processing units. In embodiments of the present invention, the microcontroller system includes a plurality of processing units, a DMA module, and an interface to an external memory system. The DMA module controls access to the external memory system by the processing units on a time shared basis by allocating time slots to each of the plurality of processing units. The processing units can access the external memory system during their assigned time slots. Data transfers to and from the memory are accomplished in packets having a fixed maximum size.

Abstract: A printing system and method performs lossy compression on a bitonal image when the printing system runs out of available memory for processing a page. The lossy compression is performed by dividing the image into subregions and by then determining a contone value for each subregion. Next, each contone value is converted to a bitonal value (i.e. either a "1" or a "0") to achieve lossy compression. In converting the contone values to bitonal values, the system determines the error associated with each conversion and diffuses the error to adjacent subregions using a random perturbation technique to determine the proportion of the error to diffuse to each subregion. When compressing color images, contone values are determined for each color plane. A relative color ordering of each contone value is also stored and used in converting the contone values to bitonal values in order to solve phasing and color alignment problems which would otherwise arise.

Abstract: A multi-interpreter printer recognizes out-of-band characters by measuring pauses in applied data streams and examining as candidate out-of-band characters data portions separated in time from other data by pauses exceeding predetermined durations. Pauses before-and after the candidate out-of-band characters may be examined, and different thresholds may be used for pre-character and post-character pauses.

Abstract: A system and process for digital printing processes commands to draw a trapezoidal image by initially rendering those commands into an intermediate representation based on pixel rows. Depending on the dimensions of the trapezoid or the regularity of the offset of the end pixels of each pixel row from the end pixels of an adjacent pixel row, data representing the trapezoid are sent to a display list as either individual pixel data, pixel row data, or a compact grouping of data derived from the intermediate representation.

Abstract: A system and process for digital printing divides an image area into segments, defines display lists for each segment, generates graphic primitives from page description language commands, stores the graphic primitives in the display lists, and adaptively compresses and converts the contents of display lists as memory requirements exceed available memory capacity. Display lists contain either uncompressed pixel representations, compressed pixel representations, graphic primitives, or combinations of the foregoing.