Process and apparatus for the insertion of insets into the image supplied by a digital scan converter

摘要

In a digital scan converter particularly for radar images, a process produces a magnified inset during the writing of the video information into the image memory. This makes it possible to increase the definition of the inset. The image memory then contains both the basic image and the insets, the latter being stored with the desired Cartesian coordinates and magnification. The Cartesian coordinates of the points of each inset are obtained by modifying data used for converting the basic image coordinates by the conversion circuits. The desired magnification is obtained by the corresponding modification of the sampling period of the analog video information during its conversion into digital form by the video processing circuits, which makes it possible to increase the definition of the inset compared with that of the basic image.