Abstract: An apparatus for and a method of judging a dotted image area using a small-capacity memory. Image data corresponding to one line out of image data representing an original image are stored in a line memory. On the line corresponding to the image data stored in the line memory, a target pixel is successively set along the main scanning direction. Image data corresponding to the target pixel is compared with image data corresponding to pixels around the target pixel. It is judged whether or not the target pixel is a peculiar point pixel on the basis of the result of the comparison. Further, the distance between peculiar point pixels is operated. The operated distance between the peculiar point pixels is referred to a predetermined judgment basis, to judge whether or not a judging area including the finite number of pixels is a dotted image area.

Abstract: The tonal resolution of an image scanner is improved by adjusting the dynamic range of an analog-to-digital converter of the scanner. A preview scan of the image is made. The image data from the preview scan is then analyzed to determine a maximum intensity and a minimum intensity. The value of the maximum intensity is used to set a white intercept of the image scanner such that a maximum digital value of the analog-to-digital converter corresponds to the maximum intensity present in the image data from the preview scan. The minimum intensity is used to set a black intercept of the image scanner such that the minimum intensity in the image data from the preview scan corresponds to the minimum digital number output by the analog-to-digital converter. Tonal resolution of the image scanner is optimized then by performing a final scan of the image with the analog-to-digital converter programmed to reflect the new white intercept and black intercept values.

Abstract: An image processing method that employs a threshold matrix to binarize image signals obtained by reading an image recorded on a film such as microfilm. A middle tone image brightness range, which corresponds to a middle or half tone image, is discriminated by referring a brightness histogram for image signals. The upper- and lower-most brightness values of the middle tone image brightness range are used to convert the elements of a threshold matrix in accordance with a predetermined conversion expression, and the converted threshold matrix used for binarization processing. Even if a film density variation occurs or if there is a background density change, binary conversion (a dithering process) can be performed, without deterioration of image quality, within a middle tone density area of, for example, a photograph.

Abstract: A process and device for analyzing image data and performing automatic optimization of a black and white image created by a scanner. The process and device performs dynamic thresholding by approximating the information level and the background level at every pixel in the image, the threshold being calculated as a function of the background and information levels at that point, and a characterization process step comparing the pixel intensity at that point with the threshold, so that if the pixel is darker, it is considered to be black, or if it is lighter, it is considered to be white.

Abstract: A system for detecting the precise location of a reflective element in a video field wherein the determined location is subsequently utilized to generate a graphic to be added to a foreground video scene utilizing compositing techniques. A signal is generated specifying a precise point in the foreground video scene identifying a position of a reflective element. The signal is derived from a peak detector which generates a pulse whenever the signal input to the pulse detector is at a maximum level for the current video field being scanned so long as the scan is not in the blanking area. The pulse is used by a vertical line counter and a horizontal pixel counter which specify the line and pixel on a horizontal scan line within a video field representing the position of the highest peak generated within that field. Graphics can be repositioned or lines or other graphic elements can be generated which track the movement of the reflective element.

Abstract: In a method of measuring noise in image signals, a number of noise estimates (SAD) is calculated (1). Subsequently, it is determined (3-9) which noise estimation interval [A, B] out of a plurality of predetermined noise estimation intervals [A, B] contains at least a predetermined number of noise estimates (SAD) and has at the same time the lowest upper interval boundary. The output noise measurement value depends on the determined noise estimation interval.

Abstract: A coring circuit for an input signal in the form of a differential input current having two components in phase opposition. A first pair of cascode transistors biased by a first reference voltage applies a first fraction of each of the components of the differential current to respectively first and second resistors. A second pair of cascode transistors biased by the first reference voltage provides a second fraction of each of the components of the differential current to a differential current output of the coring circuit and respectively to first and second branches of a differential stage that also receives voltages across the first and second resistors. Two coring current sources respectively connect first and second outputs of the differential stage to a supply voltage and are connected to each other through a third resistor.

Abstract: An improved error diffusion method for incorporating into a halftoning algorithm for processing gray scale images to counterpart binary images. The improved error diffusion method adopts a tone scale function to process the input gray scale image before proceeding with the halftoning (error diffusion) processing in order to improve the image darkening problem caused by the conventional error diffusion method and a noise correction process to eliminate the background noises resulted from the accumulated error of the conventional error diffusion method. The proceeding of the tone scaling process and the halftoning process are parallel with the correction process so that errors generated in either one will not affect the other.

Abstract: An image binarizing apparatus, which comprises an image sensor for inputting a character image or a line image, an A/D converter for digitizing the output of the image sensor, a frame memory for temporary storage of the digital image, a window circuit for generating address information for dividing the stored image into a predetermined number of partial images, a brightness extractor for obtaining the highest brightness, lowest brightness and average brightness for the pixels for each block, a neural network which provides the optimum threshold value based on pre-learned data when receiving the highest brightness, lowest brightness and average brightness, a binarizer for binarizing each pixel of a partial image block from the frame memory based on the optimum threshold value ("white pixel" when the value of the brightness of the pixel is larger than the output value of the neural network, and "black pixel" when the value of the brightness of the pixel is smaller than the output value of the neural network), a

Abstract: A technique, specifically apparatus and an accompanying method, for accurately thresholding an image based on local image properties, specifically luminance variations, and particularly such a technique that uses multi-windowing for providing enhanced immunity to image noise and lessened boundary artifacts. Specifically, a localized intensity gradient, G(i,j), is determined for a pre-defined window (300) centered about each image pixel (i, j ) . Localized minimum and maximum pixel intensity measures, L.sub.min and L.sub.max, respectively, are also determined for another, though larger, window (330) centered about pixel (i,j). Also, a localized area gradient measure, GS(i,j), is determined as a sum of individual intensity gradients for a matrix of pixel positions (370) centered about pixel position (i,j). Each image pixel (i,j) is then classified as being an object pixel, i.e., black, or a background pixel, i.e., white, based upon its area gradient, GS (i,j), and associated L.sub.min and L.sub.max measures.

Abstract: A method of picture image processing, and system for carrying out same, involves generation of a composite mapping function, for transforming gray scale values to different values in order to enhance contrast. A reduced range histogram is generated, involving removing a percentage of the total histogram counts from bottom and top sub-ranges and also removing spikes. The reduced histogram is then density averaged in order to obtain a first map function. A second map function is generated for interfacing with the characteristics of the printer to be used, and a composite mapping transform is generated by combining the two generated functions. After the composite mapping function is generated, each gray value of the image data set is transformed in accordance with the composite function, for use in printing, thereby providing an enhanced contrast image.