Device for electrical variable magnification of document image

Claim 1

A system for altering the size of an image by a desired magnification after optical scanning thereof in dependence upon a selected magnification value by providing a plurality of output scan values different in number from the number of sampled scan signals produced during optical scanning, said output scan values being representative of the density of the image at pixel locations arranged in rows and columns across the image, said system comprising: scanning means for providing a series of sequences of sampled scan signals, each such sequence of sampled scan signals being representative of the image densities at associated pixel locations in a row of pixel locations across said image, successive sequences of sampled scan signals corresponding to successive rows of pixel locations with signals correspondingly positioned in said sequences relating to pixel locations in the same column, converter means for converting said series of sequences of sampled scan signals to a corresponding series of sequences of digital scan values, control circuit means, responsive to said magnification value, for providing a plurality of interpolation control values in synchronism with said successive sequences of digital scan values, said interpolation control values indicating the spatial relationship of output scan values with respect to pairs of sequences of digital scan values, and interpolation means responsive to said pairs of sequences of digital scan values and to said interpolation control values, for interpolating between pairs of sequences of said digital scan values to provide said output scan values; said control circuit means comprising integrator means responsive to said magnification value for integrating said magnification value and providing a first portion of the integral thereof as said interpolation control values.

Claim 2

A system for altering the size of an image by a desired magnification after optical scanning thereof in dependence upon a selected magnification value by providing a plurality of output scan values different in number from the number of sampled scan signals produced during optical scanning, said output scan values being representative of the density of the image at pixel locations arranged in rows and columns across the image, said system comprising: scanning means for providing a series of sequences of sampled scan signals, each such sequence of sampled scan signals being representative of the image densities at associated pixel locations in a row of pixel locations across said image, successive sequences of sampled scan signals corresponding to successive rows of pixel locations with signals correspondingly positioned in said sequences relating to pixel locations in the same column, converter means for converting said series of sequences of sampled scan signals to a corresponding series of sequences of digital scan values, control circuit means, responsive to said magnification value, for providing a plurality of interpolation control values in synchronism with said successive sequences of digital scan values, said interpolation control values indicating the spatial relationship of output scan values with respect to pairs of sequences of digital scan values, and interpolation means responsive to said pairs of sequences of digital scan values and to said interpolation control values, for interpolating between pairs of sequences of said digital scan values to provide said output scan values; said control circuit means comprising integrator means responsive to said magnification value for integrating said magnification value and providing a first portion of the integral thereof as said interpolation control values.