Abstract: An apparatus for editing color image capable, by having a desired color in an original designated and an editing mode selected, of image editing for an image in the designated color in such an editing mode as trimming, masking, erasing, and conversion to another color. A desired color in an original image is designated by a designated color input portion and thereby designated color data for separated colors are obtained. Thereafter, the original image is scanned and image data for separated colors are obtained. The thus input image data are electrically edited in the selected edit mode based on the designated color data and the edited image data are output to an image forming unit and thereby an edited color image is obtained.

Abstract: A method of forming a plurality of printing screens, each having a selected frequency and angle, from a single masterdot of mxm elements where each element specifies a weight accorded a printing signal.

Abstract: An image input apparatus for an image scanning reading apparatus comprises a cylindrical holder for holding a plurality of originals and reference portions for calibration serving as references in reading original, a scanning head for scanning the original holder, and a memory for storing positions of the reference portions for calibration. The position of the reference portion for calibration is stored prior to the reading of the original, and when the scanning is started, the scanning head is moved to the stored position, the reference data for calibration is read by the scanning head at that position, and the corresponding original is read based on the data.

Abstract: The invention provides for deciding whether a recording dot is to be printed for the reproduction of scan dots. The scan dots being considered are compiled in an input switching network into groups, for which an arithmetic processor determines the tonal value sum. The arithmetic processor emits a signal, if the tonal value sum exceeds a certain figure. The recording dot to be printed is determined by the presence of the signal in an output switching network. This process is performed successively for increasingly larger areas of the original, that is, for increasingly larger quantities of scan dots.

Abstract: A video memory system is disclosed in which the memory module used to store video data also generates a selection signal that indicates whether the module is a monochrome or color memory module. Memory control logic generates a pixel clock which governs the rate at which pixels of data are output to a monitor, and a load clock which determines the rate at which data is read from the memory module. The load clock is generated at a first rate when the selection signal denotes a monochrome memory module, and at a second, faster rate when the selection signal denotes a color memory module. A shift register receives video data from the video memory module at the rate of the load clock, and outputs that data at the pixel clock rate. The shift register outputs a plurality of bits of the video data in parallel to a video signal generator, which converts the received data into a video signal.