Abstract: A shading corrector is provided for an image analyzer. The shading corrector is capable of storing an image presented to a raster scanning television camera included in the overall system. A memory is used to store camera video voltage variations which are representative of an object-free background field. When specimens are subsequently introduced into the field of view, the resulting video voltage may be compared in a voltage comparator to the stored background reference. A circuit is provided to correct the stored background and provision is made for using the background of a juxtaposed position in the event that the background used for the correction is covered by an object. The system is also provided with a light pen or equivalent device for identifying positions in the raster at which modifications are desired. Provision is then made for correcting images at these selected positions such as by adding to or subtracting from the images.

Abstract: An automatic counter which can scan either micro or macro sized objects in a field and provide both a visual display of the scanned objects as well as a digital count or measurement of the objects. A video camera is focused onto the sample and produces a video output signal which is processed and ultimately displayed on a video display together with an appropriate flag signal on each object identified. An aperture generator generates an electronic aperture signal whereby a particular area can be selected as to both size and shape and the selected area is displayed on the monitor screen of the video display. A compensation circuit provides additional counts to compensate for those cases where the entire area of a sample is not counted. An absolute area circuit provides a silhouette around each identified object and can provide an absolute measurement of the area within the silhouettes as well as a measurement of the total area of the selected aperture.