Abstract: An original to be reproduced is scanned line-by-line, and a scanning signal is generated for each linear, scanned region. The scanning signals represent the densities of the respective regions. A portion of each scanning signal is filtered to remove the higher frequencies. The filtered signal is differentiated to yield first density gradients, and the extreme positive and negative values of the first density gradients are determined for each region. Another portion of each scanning signal is differentiated without first removing the higher frequencies thereby yielding second density gradients. The extreme positive and negative values of the second density gradients are likewise determined for each region. A ratio of the extreme positive second density gradient to the extreme positive first density gradient is formed for each region, as is a ratio of the magnitude of the extreme negative second density gradient to the magnitude of the extreme negative first density gradient.

Abstract: A device for use in connection with an electronically controlled photographic printer is described which singles out from an advancing band of original copies those which are unsuitable for reproduction. The device includes a splice sensor for indicating the end or the beginning of an order, a sensor of individual pictures in each order, and a quality (sharpness) sensor. A resettable counter is connected to the splice sensor and to the picture scanner to produce an output pulse after a predetermined number of pictures or after the beginning or end of the order. The output pulse is applied to a selection logic circuit which has adjustable sensitivity levels. The selection logic circuit is controlled by the quality sensor to produce a "print" or "non-print" output pulse applied to the printer-controlling electronics.