An image analyser for use in a line-by-line scanning system in which a field of an article is scanned to produce a video signal representative instantaneously of a point within that field. The analyser has n delay means connected in series where n is an integer divisible by 2, the video signal being applied to the input of the first delay means. The input of the first delay means and the output of each delay means other than the nth/2 delay means in the series, are connected to the inputs of an adder. The output of the nth/2 delay means in the series is connected to the input of a signal multiplier circuit. The outputs of the adder and of the multiplier are connected to a subtracting circuit which produces an output representative of the output of the multiplier minus the output of the adder.
A system for the automatic observation and quantification of phenomena capable of being detected by fluorescence and appearing in a localized zone (8), the system comprising a source of radiation (2), optionally associated with an excitation filter (5) to send on the localized zone (8) an excitation radiation capable of producing the fluorescence, optical observation means (7) of the localized zone (8) and at least one filter (12) intended to block the excitation radiation and arranged in the path of the luminous radiation of fluorescence emanating from the localized zone (8). In accordance with the invention, the localized zone (8) is observed by a picture-taking tube (17) and through colored filters or windows on a disc (18) intercepting beam 11. The sucessive colored images are memorized and then read simultaneously.
An electronic image processing system, using image dissection by solid state devices or by scanning and sampling, applies a signal representing a succession of signal values on an array of picture elements to complementary high and low pass electronic filters to produce an output signal in which a desired image feature is enhanced and noise is suppressed. The high pass filter, e.g. FIG. 1, comprises at least one matched pair of signal weighting gradient detectors, e.g. FIGS. 3 and 5, arranged back-to-back to detect a brightness transition 10, as shown in FIGS. 4 and 6, and having their outputs cored independently. Each pair will be sensitive to gradients in a particular direction in the array, e.g. horizontal, vertical or diagonal. The system is applicable to two-dimensional spatial arrays, three dimensional spatial arrays, and also to the temporal dimension, e.g. succession of moving pictures.
