Abstract: A method of linearly filtering spatially two-dimensional signals. The signal to be filtered is applied to an electronic imaging system. For providing a scanning movement, the signal is deflected in the electronic imaging system and swept over at least one mask in which a desired corrective filter function is established in the form of a specific transmission characteristic. The light passed by the mask is detected by means of at least one photodetector placed behind the mask. The output signal of the photodetector is a representation of the filtered two-dimensional signal as a function of the time.

Abstract: A system is disclosed for forming a video representation of an X-ray shadow picture of a body. The system comprises an X-ray source, an X-ray screen, a video circuit with scanning means and display means, and a plate positioned between the X-ray source and the body. The plate has a transparency to X-radiation varying over its surface for spatially coding the X-rays. The system includes means in the video circuit for decoding the signal produced by the scanning means so that in the picture produced by the display means, the influence of the scattered radiation caused by the body is substantially eliminated.

Abstract: A system for electro-optically correlating two signals. A running representation of the amplitude variation of a first signal is observed through a mask representing the amplitude variation of a second signal. Means are provided for integrating the resultant light signal and for generating an electrical output signal representing the correlation function of the first and the second signal.

Abstract: Method and apparatus for detecting and recording breast cancer, in which the breast is exposed to X-rays, preferably in the so-called soft range, the transmitted beam of rays is scanned by means of a moving, strip-shaped screen and the image of the strip-shaped screen is picked up with a television pickup tube moving along with the screen, and is displayed on a monitor tube.

Abstract: A method and apparatus for X-ray examining organs and parts of the body of human beings and/or animals, wherein the X-ray image is reproduced by means of a television circuit on the viewing screen of a monitor. Photographs of the X-ray image are taken as a film disposed in front of the screen of the monitor is exposed to the monitor picture for a period of time including a plurality of image scan cycles. During this period of time the gain in the television circuit is varied in accordance with a time function such that the brightness of the monitor picture remains constant during this period.