Abstract: A reference marking device for image transmitters includes a transmitter (FIG. 1) and a receiver (FIG. 3). The transmitter includes a scanner, which optically scans an image, and generates an image signal corresponding to the content of the image. The receiver receives the image signal and records the received image signal on an image base as a reproduction of the scanned image. The image base is provided with reference marks for registration of a series of separate, associated image reproductions, obtained preferably by means of color separation of the scanned image. The transmitter additionally generates and transmits reference signals. A reproduction device, included in the receiver, registers said reference marks in correspondence with the reference signals.

Abstract: To alter the brightness of selected portions of an image a representation of the image is presented on a display and is stored in a memory. The image representation is divided into a number of fields. A user may select an arbitrary one of the fields and indicate a desired change in its brightness, as presented on the display, by means of a field selector and correction keys. Each such change is also registered as a change in values stored in a corresponding region of the memory. Using interpolation, a control unit automatically modifies the brightness level of non-central portions of the selected image field, and of image fields adjacent to it, in order to eliminate sharp and obvious transitions in brightness at the borders of the respective fields.

Abstract: A device for long-distance transmission of images includes a transmitter and a receiver, connected by a communications line. The transmitter contains a device which scans a picture in a linear pattern to form an electric signal modulated to represent the brightness of the picture in picture points along the scanned lines. The receiver has a picture reproduction device and a driver for moving the reproduction device relative to a picture-supporting surface in a linear pattern corresponding to the linear scanning pattern of the transmitter. Upon receiving this signal the picture points are reproduced line by line with a brightness which corresponds to the modulation of the electric signal. The transmitter contains a memory and a controller arranged to divide the transmission of the signal created by the scanning device into segments and, upon sensing a maneuver signal, to direct the memory to retransmit a portion of the signal corresponding to one segment to the receiver.