Computer-aided reconstruction of cathode images obtained by high speed photography of high current vacuum arcs

The images of the cathode obtained by high-speed photography are ellipsoidal because they are taken at a small angle (about 10/spl deg/) to the cathode surface. For this reason, it is very difficult, if at all possible, to draw conclusions about the spatial distribution of cathode spots and current density over the cathode surface. One may perform inverse parallel projection, but previously it was necessary to free the image from the noise of the interelectrode plasma radiation and other noise sources. In this paper, we propose a method of image filtering based on contours of equal intensity evaluation, with subsequent determination of the cathode spots distribution.