[A new TV-bronchoscopy method using a video endoscope and digital processing of the endoscopic color image]

The TV-bronchoscope dose not have an image fiber bundle, which is instead replaced by a monochromatic C.C.D. (charge-coupled device). This system consists of a bronchofiberscope, a computer, a TV camera, a frame memory and a color CRT display. The enhancement of an endoscopic color image is one typical example of color image processing. Firstly a color image is divided into luminance information and color information, and only the former is processed for enhancement. The luminance information is filtered so as to eliminate the fiber bundle structure, and the spatial frequency band characterizing the structure is then emphasized. Finally the processed luminance information and the non-processed color information are combined to reconstruct the color image. In this way, a processed color image can be obtained without changing the color balance of the original image. Using this process, blood vessels and surface irregularities are emphasized by the newly developed digital processing method. We have applied it for localization of hilar-type early lung cancer, which progresses on the surface, and have obtained good results.