An apparatus is described which is responsive to a sequence of received data-compacted pixels representative of a coarse two-dimensional image of a remote scene for reconstituting picture point intensity signals representative of the smoothly shading in of the coarse image. In a preferred embodiment the apparatus comprises: first means for utilizing the first one of the sequence of received data-compacted pixels to develop the initial intensity of the first one of a plurality of horizontal lines in a reconstructed image of the remote scene; second means for selectively generating horizontal and vertical gradient information as a function of the received pixels; third means selectively responsive to the initial intensity of any given horizontal line in the reconstituted image and to the associated vertical gradient information for developing by a first interpolation the initial intensity for the following horizontal line; and fourth means selectively responsive to the initial intensity of any given horizontal line and to the horizontal gradient information associated with that given horizontal line for computing a sequence of picture point intensities between each adjacent pair of received pixels in that horizontal line by a second interpolation.
It is possible to clearly extract objects such as characters and line figures by eliminating the effect of shading from an input image containing self-shaded objects and/or vaguely contoured objects together with distinctly contoured object and thereby to extract all objects clearly and completely. A sample point setting portion sets sample points, a sample point shade calculating portion determines an optical density of shading at each sample point according to an optical density distribution of pixels in a reference block including the sample point at the center thereof. A shade calculating portion determines shade densities at the other points than the sample points and generates shade image, a shade removing portion generates a shade-removed image by removing the shading effect from the input image by using the shade image. A quantizing portion binarizes the shade-removed image and an image output portion outputs the obtained binary image.
Method of and apparatus for converting a first two-dimensional image on first column direction and row direction scales to a second two-dimensional image on second column direction and row direction scales at a high speed, in which use is made of the periodicity of the positional relation between the image elements of the first image arranged in matrix and having various data values and the image elements of the second image arranged in matrix and having various data values to determine, for each one of the second image elements, four second image elements lying on the intersections between two adjacent rows and two adjacent columns in the first image element matrix which rows and columns surround the second image element and constitute a reference from for the second image element, and in which the data value for each second image element is calculated on the basis of the data values of the four first image elements associated with the first image element and the vertical and horizontal coordinates within the reference frame. Both of the above-mentioned periodicity and the coordinates are defined in terms of the ratios between the first and second scales for the first and second two-dimensional images, i.e., magnifications.
An imaging system that acquires and stores every other line to be used in a display image and interpolates the stored lines to obtain the lines between the stored lines for display purposes.
A shading circuit has a unit for calculating coordinates and intensities of points inside a polygon based on X, Y, and Z coordinates and intensities of vertexes of each of polygons constituting a solid model. This unit includes a preprocessing section for obtaining the depth change .DELTA.Z/.DELTA.X of Z coordinate for each unit change in X coordinate and the change .DELTA.I/.DELTA.X of intensity for each unit change in X coordinate, based on X, Y, and Z coordinates and intensities of three vertexes of each of triangular polygons constituting a solid model, and a digital differential analyzer until for obtaining Z coordinates and intensities of points inside each polygon commonly using .DELTA.Z/.DELTA.X and .DELTA.I/.DELTA.X when the X and Y coordinates of the points are determined.
A digital subsystem for improving the resolution of a TV digital signal by inserting additional digital samples into the digital TV signal in response to the correspondence of the digital signal and predefined patterns. The digital subsystem is a logic circuit which is responsive to received digital samples to group these digital samples into sets of samples. The digital circuit then calculates the slope between pairs of digital samples of each set and utilizes the calculated slopes to determine the correspondence to the predefined patterns. The determined predefined pattern designates the digital sample to be inserted into each set. The inserted digital sample is either equal to one of the digital samples or the average between two of the digital samples of each set. The calculation of the slopes results in a logical "0" for a constant slope and a logical "1" for a negative or a positive slope. An Exclusive OR gate is utilized to make the determination of whether to use a value equal to one of the digital samples of the set or the average of the value of two of the digital samples. A slope is considered constant if the difference between the pair of digital samples is less than a value calculated from range information of the set of samples.
