DIGITAL IMAGE ORIENTATION MARKER

摘要

An orientation marker (16) for a digital radiogram (10) formed by a pluralit y of pixels arrayed along a plurality of rows and columns. The pixels have densities which represent the radiogram optical density at each pixel point, and the densities are represented by digital values. The marker is made by a number of marker pixels arrayed along at least one row and one column of the radiogram. Each of the pixels forming the marker (16), have a marker pixel digital value which has been selected to form an asymmetrical marker pixel pattern on the radiogram, replacing the original radiogram pixel values.