Abstract: An image processing apparatus and method include a plurality of different background suppression data acquisition modes selectable by a user in order to obtain background suppression data from a document being reproduced. The obtained background suppression data is used by an image processing unit to suppress the background region of the document being reproduced. The user is able to select one of the plurality of background suppression data acquisition modes depending upon the user's desire for high speed document reproduction versus the required quality of background suppression. In this manner, the user is able to determine whether document reproduction speed or background suppression quality is to be emphasized.

Abstract: A system and method for selective scaling of an image by selective implementation of a window averaging processing technique or an interpolation processing technique. For enlargement scaling, the interpolation processor is implemented. For reduction scaling, the window averaging processor is implemented. For anamorphic scaling, the window averaging processor may be selected and implemented for reduction processing pursuant to a two-pass processing technique wherein the interpolator processing will be implemented thereafter.

Abstract: The background grey-level of a document is determined based on the gain of the document. A histogram is generated and compressed. The standard deviation of the distribution curve of the compressed histogram is determined. A gain factor is determined using the mean and standard deviation. Using the background grey-level, the dynamic range of the document is adjusted.

Abstract: A method and apparatus for digital image reduction using an improved “extendible” perspective projection technique which allows for flexible control of the averaging cell or window size separately from the reduction ratio to improve moir{acute over (e)} suppression or sharpness as desired in the resulting reduced-size image. The extendible perspective projection technique can also be implemented together with ordinary perspective projection or together with a combined one-dimensional filter and linear interpolation technique to produce a reduced-size image of a quality comparable to those produced by the prior technique of using a two-dimensional pre-filter prior to interpolation at a much lesser cost due to the reduced number of required scanline buffers.

Abstract: A method and apparatus are provided for classifying image data. A peak/valley detection device may count peaks and valleys within a window. A local roughness of the image data may be determined and the data may be classified based on the peak/valley count and the local roughness.

Abstract: A system and process prints a high resolution image on a high addressable image output terminal by converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction. The converted image is then processed and binarized prior to being printed on a high addressable printer. The system or process utilizes a conversion circuit which includes a two-bit per pixel packing circuit, a scanline buffer circuit, a logic circuit, and a look-up table. The conversion circuit initially converts the image into an image having a lower resolution in the fast-scan direction and a higher pixel depth resolution. Thereafter, the image is further converted to an image having a lower resolution in the slow-scan direction and a higher pixel depth resolution. This conversion of a high resolution image to a lower resolution is carried without any substantial lost to the image content data.

Abstract: An error diffusion process adds an error value to an input grey image value to produce a modified input grey image value before comparing the modified input grey image value with a predetermined threshold value. A rendering value and error is generated based on the comparison. An error equal to the modified input grey value is generated when the modified input grey value is less than the predetermined threshold value, and an error equal to the modified input grey value minus an effective spot area value is generated when the modified input grey value is equal to or greater than the predetermined threshold value. The effective spot area value is retrieved from a look-up table having a plurality of effective spot area values based on the input grey image value.

Abstract: The present invention is a method and apparatus for tuning the appearance and controlling dot growth of bitmap images rendered on a printing system. The invention operates to recognize those pixels with a bitmap image that are appropriate for alteration and, in response to downloadable output values, adjusts the identified pixels so as to ensure a desired output.

Abstract: An apparatus for processing an input image, represented by an input bit stream including a plurality of first bit sets, is provided. The apparatus includes a device for processing the input bit stream in such a manner that each of the first bit sets is represented by a second bit set with each of the second bit sets having less bits than each of the first bit sets and a selected number of bits in the input bit stream, corresponding to image-related information, being discarded as a result of the encoding. The apparatus is provided with an electronic volatile memory for storing a resulting encoded bit stream and a bit stream analyzer for analyzing the stored encoded bit stream to generate positional signals. The apparatus is further provided with a reconstruction circuit for reconstructing the stored encoded bit stream, by reference to the positional signals.

Abstract: A system and process prints a high resolution image on a high addressable image output terminal by converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction. The converted image is then processed and binarized prior to being printed on a high addressable printer. The system or process utilizes a conversion circuit which includes a two-bit per pixel packing circuit, a scanline buffer circuit, a logic circuit, and a look-up table. The conversion circuit initially converts the image into an image having a lower resolution in the fast-scan direction and a higher pixel depth resolution. Thereafter, the image is further converted to an image having a lower resolution in the slow-scan direction and a higher pixel depth resolution. This conversion of a high resolution image to a lower resolution is carried without any substantial lost to the image content data.

Abstract: To make the architecture of an image processing module of a monochrome printing machine convertible to a full color printing machine, bypass circuits are included in the luminance processing circuit of the monochrome printing system. These bypass circuits are inserted between a conventional shading circuit and conventional two-dimensional filter and auto-segmentation circuit of the luminance image processing system and between a conventional brightness adjustment circuit and a conventional one-dimensional image processor/screening circuit of the luminance image processing system. This inclusion of bypass circuits enables a chroma processing circuit to be installed in parallel with the luminance processing to make the monochrome system convertible to a full color system. The converted full color system utilizes the luminance processing system of the monochrome system to realize fully color processed signals ready for transmission to a printing subsystem.

Abstract: The present invention relates to subsampling processors and a three color sensor array that may be employed to supply subsampled chrominance data to a printing machine, a computer memory device or other device. In one embodiment of the present invention, a three color array of the present invention scans features of an object using an array of one or more subsampling sensor sets spanning a fast scan direction width of n times m (preferrably 2) pixels, with each set having aligned in a slow scan direction column m pixel-sized green sensors aligned in a fast scan direction line for determining pixel-by-pixel green color and luminance, a red sensor extending m pixels wide in said fast scan direction and m pixels long in said slow scan direction for detecting red color and a blue sensor extending m pixels wide in said fast scan direction and m pixels long in said slow scan direction for detecting blue color.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.