Abstract: The invention relates to an apparatus for obtaining an enlarged image of a part of the field of view of an IR camera. A device (4,6) for horizontal deflection and a device (5,17) for vertical deflection deflect IR rays (7) incident on the camera towards detector elements (8). These sense the field of view along parallel scanning lines costituting bands, and generate video signals so that the lines can be presented on a display screen (3). In accordance with the invention the device (5,17) for vertical deflection forms a smaller portion in height of the field of view than normal height thereof. The bands partially overlap each other so that the scanning lines in one band fall in the space between scanning lines in a preceding band. The bands are individually noted in the reading order in separate memory (C, D, E). The data for the lines falling in the space will be noted at addresses which do not correspond to their true position in the field of view.

Abstract: In displaying on a viewing screen an image generated by output signals from a radiation-sensitive detector, e.g., an infrared detector, it may occur that weakly contrasting details in the image are lost when the light intensity of the image covers too great an intensity range. In one method of avoiding this loss of details, the amplification of the low-frequency portions of the video signals is regulated adaptively by calculating two statistical parameters, characteristic for the statistical properties of the signal values, and adjusting the amplification such that a selected image intensity corresponds to the calculated parameters.