Abstract: The present invention is methods, apparatuses and systems for dynamic switching of image processing techniques. Image processing techniques include resolution enhancement for improving the quality of text and line art, halftone image enhancement for improving the quality of gray value or halftone images and toner conservation for reducing toner consumption. Toner conservation may be used simultaneously with other image enhancement processing techniques according to the present invention.

Abstract: A pulse width modulator includes a clock operative to count successive discrete time intervals having a period equal to a desired full pulse width, and configured to generate a clock signal. The pulse width modulator also includes an adjustable delay line comprising a plurality of delay line elements, each delay line element operative to generate a clock signal at a specific location, which when combined with a transitional instruction, will produce a modulated output that has a plurality of transitions within the clock period. The pulse width modulator further includes processing circuitry configured to receive the clock signal and a pulse code input and operative to select one of the delay line elements to generate a clock signal at a specific location to produce a single modulated output that transitions at a desired modulated frequency. A method is also provided.

Abstract: An electrophotographic imaging device uses a transition placement device to position transitions in a stream of video data. A rasterizer included in the electrophotographic imaging device generates pixel data bytes based upon data received from a computer defining an image. A converter generates codes specifying positions of transitions within a pixel time period corresponding to a pixel data byte. The transition placement device includes a phase measuring device to measure a timing offset between an active edge of a beam detect signal and a rising edge of a reference clock. A transition adjustment device adjusts the positions of the transitions specified by the codes relative to the rising edge of the reference clock using the timing offset. Transition generation logic generates the transitions for the stream of video data using the adjusted transition positions received from the transition adjustment device.

Abstract: An embodiment of an edge placement device is supplied with transition data to generate transitions during a pixel time period corresponding to the transition data. The transition data is supplied by pulse code logic that converts pixel data to the transition data. The embodiment of an edge placement device includes first edge placement logic coupled to taps from a first clock delay chain and second edge placement logic coupled to taps of a second clock phase delay chain. Also included is a phase splitter that generate a first and a second clock phase coupled, respectively, to the first and the second clock delay chain from a clock corresponding to a pixel time period. The first and the second clock phase have rising edges on alternate cycles of the clock. The first and the second edge placement logic each include a plurality of D flip flops.

Abstract: Text and line art image data is distinguished from halftone image data for selectively enhanced rendering thereof. Specifically, a method of rendering a raster pixel image from a stored bitmap includes (i) determining whether an orphan pixel is detected within a bounded sampling window of the bitmap, and, (ii) processing at least one selected pixel of the bitmap within the sampling window relative to the determining of whether an orphan pixel is detected. In general, an orphan pixel is defined as an isolated white or black pixel in a halftone image. In one embodiment, an orphan pixel is recognized as having a predefined pixel value and as having no other pixels with that value adjacent thereto within the sampling window. In the event an orphan pixel is detected within the window, then the bitmap within the window is determined to be halftone image data and the selected pixel is processed accordingly.

Abstract: An apparatus derives data to enable a fill action during operation of a print device along a scan line. The apparatus includes a processor which determines, for each of a sequence of contours of a glyph, point of intersection values between a scan line and the contours. The sequential point of intersection values indicate OFF-to-ON and ON-to-OFF transitions required of the print device. Sequential OFF-to-ON and ON-to-OFF transitions comprise a transition pair. The apparatus includes a memory comprising 2N storage positions for storage of N transition pairs. Comparator circuitry is coupled in parallel to the 2N storage positions. A controller operates the comparator circuitry to determine an order of all OFF-to-ON point of intersection values and an order of all ON-to-OFF point of intersection values in the 2N storage positions.