Abstract: The translation of an optical image into video signals by a video sensor illuminated by the optical image is adjusted by illuminating the sensor at a first level of light intensity sufficient to provide the video signals at maximum amplitude while adjusting the amplitude of the video signals to a first level, and then illuminating the sensor at a second reduced level of light intensity while adjusting the black level of the video signals so that the black level is at least equal to the amplitude of the signals produced by the sensor in the absence of illumination.

Abstract: A color converting device for converting R, G and B image signals representing red, green and blue colors, respectively, into a three color or four color printing data indicative of three colors of yellow, magenta and cyan or four colors of yellow, magenta, cyan and black, which device comprises a divider for dividing the image signals into achromatic and chromatic color components for each picture element; a first converter for converting the chromatic color components so divided into a first color conversion data Y1, N1 and C1 representative of the yellow, magenta and cyan colors, respectively; a second converter for converting the achromatic color component into a second color conversion data Y2, M2 and C2, or into a third color conversion data K; an adder for summing the first and second color conversion data Y1, M1, C1, Y2, M2 and C2 together to provide the three color printing data, or an output circuit for outputting both the first color conversion data Y1, M1 and C1 and a third color conversion data K