1. Apparatus for producing a halftone image reproduction of a continuous tone original image comprising: means scanning said original image along a series of scan lines to provide reflected light from continuous sets of concentric sharp and unsharp areas of said image, means responsive to said reflected light from said concentric areas to produce continuous sets of corresponding sharp and unsharp analog signals proportional to the light reflective density of said concentric areas, analog to digital conversion means receiving said sharp and unsharp analog signals, means providing a first set of incremental control parameter signals in accordance with a predetermined one of a series of reproduction ratios which vary from an enlargement to a reduction of said original image to define scan sample points on said series of scan lines, means responsive to said first set of incremental control parameter signals for controlling said analog to digital conversion means to produce successive sets of digital sharp and unsharp gray level data signals at said scan sample points proportional to the light reflective density of successive sets of concentric sharp and unsharp areas of said image at said scan sample points with the sharp area at each scan sample point corresponding to the general area of a predetermined portion of a halftone cell, means providing a second set of incremental control parameter signals in accordance with said predetermined one of said reproduction ratios to define the distance between succeeding scan lines, means responsive to said second set of incremental control parameter signals for positioning said scanning means to succeeding scan lines, means combining said successive sets of digital sharp and unsharp gray level data signals in a predetermined manner to produce a succession of digital resultant gray level data signals, means converting said succession of digital resultant gray level data signals to a succession of digital halftone data signals, and means responsive to said succession of digital halftone data signals for producing a halftone image reproduction corresponding to said continuous tone original image.