Abstract: An apparatus for receiving input data values representing an array of picture elements of a source image containing one or more bar code regions, whereby the input data values are converted to bi-level values representing black or white states which are stored in an image memory, while in addition the bi-level values are processed to obtain data representing an image in which a "skeleton" central portion of the bar code region appears as an all-black region, while background black regions are eliminated. A central position and the slope of a central axis of the bar code region are computed based on that "skeleton" region, and data values in the image memory which conform to the central axis are then read out, to read the bar code data.

Abstract: An image signal processing apparatus for converting input signal values representing density levels of successive picture elements of an image to corresponding bi-level signal values, whereby a conversion error for an object picture element is apportioned among a set of unprocessed adjacent picture elements, to update respective values of accumulated error. Each input signal value is compensated, prior to conversion, by a value derived from the total accumulated errors of the object picture element and these adjacent picture elements, while the conversion error is derived by subtracting from the bi-level output value a value obtained by compensating the input signal by the accumulated error for the object picture element.

Abstract: An image signal processing circuit for converting step-gradation density values (I.sub.xy) of successive picture elements to bi-level values (P.sub.xy) for display by a bi-level display device, in which a bi-level error (E.sub.xy) between a bi-level value determined for a picture element and an appropriate density value for the element is apportioned among a set of peripherally adjacent picture elements (A to D) by computing a corresponding set of error apportionment values (G.sub.A to G.sub.D), and in which a difference between the sum total of these apportionment values and the bi-level error is derived, and error apportionment is modified such as to eliminate the effects of this difference. Improved reproduction is thereby attained of image regions which are of uniformly high density or low density.

Abstract: An image signal processing circuit for converting a continuous tone image signal to a bi-level image signal, for producing a spatial gray scale image on a bi-level display device such as a gas plasma display panel. Respective values of apportionment factors (K.sub.A to K.sub.D) used for apportioning a bi-level conversion error of each picture element of the image among a plurality of picuture elements (A to D) positioned peripehrally adjacent thereto are periodically altered, in a periodic or random succession of values, to thereby effectively eliminate the generation of a texture pattern in display regions corresponding to areas of uniform density in the original image.

Abstract: The invention relates to a method for processing an image signal such that areas of original image data are sequentially scanned with a scanning window having a size corresponding to M picture elements in units of a predetermined number of picture elements so as to perform halftone display in accordance with black-and-white binary distribution with respect to the signal levels of the picture elements within the scanning window every time the scanning window is moved. The picture elements within the scanning window are assigned an order of preference in accordance with their image signal levels. A sum of the image signal levels of the picture elements within the scanning window is calculated, and A and N of the equations S=C.times.N+A are calculated, where C is a predetermined image signal level (e.g., black level and maximum level), N is an integer, and A is the image signal level falling within the range O.ltoreq.A<C.

Abstract: An image processor for reproducing a continuous tone image such as a photograph in a black-and-white binary dot image (halftone image) has a linear correction section for converting a sampled digital image signal in a predetermined manner controlled by black and white densities of an original, thereby performing linear conversion between the continuous tone image and the halftone image. The image processor also has another correction section for performing profile emphasis to obtain a clear halftone image.

Abstract: The invention relates to a method for processing an image signal such that areas of original image data are sequentially scanned with a scanning window having a size corresponding to M picture elements in units of a predetermined number of picture elements so as to perform halftone display in accordance with black-and-white binary distribution with respect to the signal levels of the picture elements within the scanning window every time the scanning window is moved. The picture elements within the scanning window are assigned an order of preference in accordance with their image signal levels. A sum of the image signal levels of the picture elements within the scanning window is calculated, and A and N of the equation S=C.times.N+A are calculated, where C is a predetermined image signal level (e.g., black level and maximum level), N is an integer, and A is the image signal level falling within the range 0.ltoreq.A<C.

Abstract: A method for processing a video signal comprises defining a successively shifted scan window with respect to the signal level of each picture element from which said video signal has been derived, totalizing the quantum numbers of the picture elements in the scan window corresponding to the original screen dot, and reconstructing black picture elements corresponding to the total value of the quantum numbers faithfully to the area of the original dot, and an apparatus for carrying out the method.

Abstract: In a variable density scanner a light beam of a fixed spot size is scanned on an original along each of a plurality of parallel line paths at a constant speed to generate a video signal and successively shifted to the next line path. The video signal is sampled to generate a video sample. Each of the line paths is divided into a plurality of line segments so that each segment derives a plurality of video samples and the line paths are formed into a plurality of groups of adjacent line paths so that the video samples are derived from a plurality of patterns of rows and columns. The total value of the video samples of each pattern is arithmetically divided by their number in response to the control signal to derive an average value.