GB1400806A - Image reproduction systems - Google Patents

Abstract

1400806 Facsimile apparatus CROSFIELD ELECTRONICS Ltd 19 Nov 1973 [4 Dec 1972] 55902/72 Heading H4F In the facsimile reproduction of a monochrome or coloured original, localized modification, i.e. retouching, of density values (corresponding for example to flesh tones) which occur only within selected (flesh) areas of the original is effected by tracing the boundary of each area of the original within which modification is to take place to derive boundary-defining signals which are stored and used during subsequent scanning of the original to cause the facsimile output signal or set of facsimile colour output signals to be modified only when the corresponding scanned element is within a traced boundary. Modification of the signals within a traced boundary may also be effected when they define a predetermined hue or range of hues, a flesh tone correction of the type described in Specification 1,294,191 being used (Fig. 4, not shown). The boundary-defining signals may be generated by manually rotating a cylinder carrying the original and manually displacing a reference device along a lead screw parallel to the cylinder axis to thereby cause the reference device to trace the boundary of each area, photo-electric pulse generators being coupled to cylinder and reference device so that, by counting the resulting pulses, Y and X co-ordinate signals for the boundary of each area are obtained. These signals are stored and when the coordinate signals corresponding to the position of the analysing head of the facsimile scanner lies between these stored co-ordinate signals the video output signals from the analysing head are fed via a special tone correction unit instead of a standard tone correction unit to the exposing head of the facsimile apparatus. The correction units may comprise matrix stores loaded in a preliminary operation with corrected colour information as described in Specification 1,369,702. The tone correction arrangement may include an interpolator of the type described in Specification 1,369,702, the colour component signals being digitized (Fig. 3, not shown).