Abstract: In the image processing apparatus a matrix selector selects a position matrix for determining the gradation direction. The gradation direction is the direction of a contrast of a gradation at a position of a target pixel and a dispersion matrix for determining a spatial frequency at the position of the target pixel. Further, a pixel interpolator divides the target pixel into still smaller pixels. A table selector selects a conversion table for determining a gradation level of the smaller pixels based on the gradation level of the target pixel, the position matrix and the dispersion matrix.

Abstract: An image processing apparatus for improving the performance of reproducing an image edge and obtaining a preferable image output including an edge judging unit for judging the presence or absence of both left and right edge pixels of an input image. The apparatus further includes plural halftone processing units and a selection unit for selecting one of the plural halftone processing units based on a result of the judgment result of the presence or absence of either of the left or right edge pixel.

Abstract: An apparatus for circulating documents among a number of computer terminals in an office. The apparatus includes a device for reading images which are then stored. The image may then be read out from the storage. A controller controls the storage of the image and the reading of the image from storage. The apparatus also includes a device for forming a network system with a number of terminals so that the various terminals can read images from storage. The apparatus will automatically delete data from the storage under various conditions.

Abstract: In a color thermal transfer recorder, L is set to a distance from a printing position to first and second sensors for detecting each of marks, q is set to a pitch between the marks, N is set to an integer equal to 2 or more, S is set to an arbitrary value from zero to the pitch q, and .delta. is set to an arbitrary value from 0 to 4 mm. The values L, q, N, S and .delta. are set such that the following formula L=N.times.q+S+.delta. is satisfied. The values L, q, N, S and .delta. may be set such that the following formula L=N.times.q+S-.delta. is satisfied. In this recorder, various kinds of marks are formed on an ink sheet and are detected by the first and second sensors so that a conveying operation of the ink sheet is controlled. In accordance with this structure of the recorder, the distance from the printing position to the first and second sensors is increased so that a degree of freedom in design of the recorder is increased.