In a process of geometrically deforming an original picture by changing the picture element pitches, weight coefficients g calculated for the picture elements according to preselected magnification variation factors are read out of a first memory whenever original picture data F are read successively, the contents Fg of a second memory are read out according to addresses defined by the data g and F, and the addition result of the data Fg is divided by the addition result of the data g, thereby to obtain a geometrically deformed picture from the original picture.
A set of two processors operates on image pixel data using polynomial interpolation to generate pixel data for a spatially varied image. Image data is first stored in a buffer memory, and constants used in the polynomial interpolation are stored in a constants memory. One processor operates on the data from the buffer memory using constants from the constants memory, and the interpolated data is then stored in a display memory. The second processor controls the interpolation process by addressing the memories for the retrieval and storage of data.
A method of enlarging or reducing the size of a halftone one bit per pixel raster image without changing the screen pitch is disclosed. First, there is a determination of whether the current byte is on an image edge using any edge detection means. If the current byte is on an edge, the nearest neighbor algorithm is applied to the original image on a bit by bit basis to prevent edge jaggedness. If the current byte is not on an edge, the nearest neighbor algorithm is applied on a byte by byte basis to prevent Moire patterns in the solid areas of the image.
In an image transformation method in an image display apparatus for displaying a digital image derived by transforming an original digital image, each of intensities of second picture elements including at least three points on the original digital image surrounding a first point on the original digital image, corresponding to coordinates of a first picture element on a transformed digital image is weighted by a value related to a length of at least one of two sides of a polygon which apexes are the second picture element opposing to its own second picture element and the first point, the two sides surrounding the first point, and the intensity of the first picture element is determined based on the calculated intensities of the second picture elements.
Apparatus and method for converting image data of an image matrix to an image matrix having a different number of matrix points. Each new image pel has a gray scale determined by considering its position with respect to the nearest neighbors of an original image pel. A look up table is provided having a plurality of planes, each plane including a plurality of storage elements arranged in columns and rows. The storage elements contain the gray scale level of a new image pel. The look up table plane represents the gray scale levels for a plurality of positions within the neighborhood. The planes are addressed by the gray scale levels of the pels comprising the neighborhood, and the storage elements within a plane are addressed by the position of the new pel with respect to the neighbors.
An apparatus for reproducing an image with a desired magnification other than that expressed in an integer comprises a key switch for inputting the desired magnification. When reproducing the image with the selected magnification, it is necessary to interpolate pixel dots by increasing or decreasing the number of pixel dots for each predetermined region. The pixel dots are output in accordance with interpolation tables. The image reproducing apparatus further comprises an interpolation table preparing device for preparing a plurality of interpolation tables having different positions for interpolating the pixel dots in each predetermined region in accordance with the desired magnification, and a switching device for switching among the plurality of interpolation tables at random for each scan line. Since the plurality of interpolation tables are switched for each scan line, no regular patterns appear on the reproduced images.
