Abstract: This invention provides a method for obtaining a video signal corresponding to selected parts of an image by separating from the video signal relating to the whole image that portion relating to the selected parts. The method includes a comparison of a boundary signal derived from the separated video signal with that relating to the whole image and adjustment of the separation to correct for inaccuracies in the separated signal in respect of the boundaries of the selected parts. The invention also provides apparatus for deriving the boundary signal and displaying the two signals for visual comparison.

Abstract: A device is described for obtaining counting and calculating stereological data. The device includes a number of separate counters each of which can be used to accumulate the numerical value of a point count or intersect count made using a test system typically in the form of a matrix of perpendicular lines superimposed over a display of the field to be analysed.The apparatus provides for enlarged real images of the specimen which may be on film or a microscope slide, to be formed on a frosted glass screen on which a test pattern is visible.First computing means is provided for computing from information relating to the test system the numerical values of constants required by a second computing means to convert the numerical values of point or interest counts into numerical values of different parameters of the specimen.

Abstract: Improvements and modifications are described to an image analyzing system in which an image of a field under analysis is displayed on a television monitor screen and features can be edited by adding or subtracting feature content to or from the display (and corresponding signal content to or from the signal which is to be processed for analysis) using a light pen.One improvement provides for straight line interpolation between points in the display selected by the light pen during successive frame scans, so that a continuous trace and therefore corresponding signal is produced in the display corresponding to the path traced out by the light pen.Another provides for an alarm signal to be generated if the storage facility used for storing the locus of the trace to allow its reconstruction during successive frame scans, becomes more than a given percentage occupied.

Abstract: An improvement in methods of image analysis is described whereby the time required for analyzing certain types of images can be substantially reduced. The invention utilizes the light integration characteristic of a television camera to combine a succession of images applied thereto into a single composite image. A video signal of the composite image is then obtained by scanning in the usual way. Analysis of the video signal is performed in a known manner after threshold detection.The invention is of application to the analysis of microscopic specimens which are generally black or dark grey and which include a few widely spaced white or light grey features, on which the analysis is to be performed.One embodiment utilizes a single scanner and switching devices for alternately producing scanning and not scanning.

Abstract: An image analysis system is described in which the video signal information is processed so that only the measurements on any one feature are delivered to the output during any one frame scan.In a modification, the function of the computing circuit performing the measurements on the signals arising from scanning the features is changed from frame scan to frame scan until a complete programme of different parameter measurements has been performed on the signals relating to one feature (one parameter being dealt with during each frame scan). The analysis is then transferred to the next feature in the field as outlined above and the same programme of measurements is carried out on the next feature.

Abstract: A method and apparatus is described for performing controlled erosion of electrical signals relating to detected features in an image which is scanned. The erosion is performed by counting (in an up or down counter) n timing pulses in each sequence corresponding to a detected signal pulse before an overflow signal indicating that n timing pulses have been received is generated. The overflow signal is used to release subsequent timing pulses which are then analysed by counting. The timing pulses so released correspond to the portion of a detected feature left after erosion from the leading edge.The method is applied parallel, perpendicular and at non-orthogonal angles to the line scan direction.The apparatus required can be minimised by applying down-counting techniques and storing a signal to indicate complete erosion in one direction instead of recirculating large quantities of information from line to line.