Abstract

A method and apparatus are disclosed for reproducing an original gray scale image that may be divided into an array of discrete picture elements. The method comprises the steps of scanning each of the picture elements in the array on the original image to determine its gray level and location in the array and generating sequential signals that contain data indicative of the gray level and location in the array of each of the scanned picture elements. The gray level of the entire array is calculated from the data on each of its individual picture elements in accordance with a gray scale function. On a reproduction medium in an array of reproduction locations corresponding to the picture element array, locations are sequentially darkened in order of decreasing gray level, beginning at the location that corresponds to the scanned picture element having the darkest gray level, until the gray level of the reproduction array substantially equals the calculated gray level of the scanned picture element array. Therefore, the gray level distribution of the picture element array is substantially duplicated on the reproduction array to provide maximum resolution within the capability of the scanning and darkening systems. In addition, this method reduces the amount of data processed in order to reproduce maximum image resolution. The apparatus for performing this method comprises various components for performing each of its steps.

Other References

• S K. Gupta, "Production of Pseudo-Half-Tone Images," I.B.M. Technical Disclosure Bulletin, vol. 19, No. 1, pp. 290-291, 6-76