AUTOMATIC DETECTION METHOD OF FOREGROUND AND BACKGROUND OF DIGITAL RADIOGRAPHIC IMAGE

摘要

PURPOSE: To automatically separate the desirous area (an image picked-up body part) and nondesirous part (a foreground area irradiated with an extremely small amount of radiation or a background area around a body part irradiated no-attenuation radiation by using a radiation limiter) of a digital radiographic image from each other. CONSTITUTION: The edge of image signals is detected (24) and the image signals are resolved into non-superposed adjacent block sets of pixel signals (26). Then the pixel signal blocks are classified into homogeneous blocks and nonhomogeneous blocks as the functions of the edge density and variation (28) and, by applying a syntax rule for detecting the nonhomogeneous blocks of pixel signals in the foreground and background and homogeneous blocks of pixel signals in an object and detailing the blocks in which the object and foreground and background coexists in a mixing state (30), separated image signals are generated (32).