Image Enhancement Technology for an 8K Endoscope

At present, 8K is the highest resolution of video systems, and its research was originally implemented for broadcasting services. In addition, 8K has an important application in medical field, and its application in an endoscopic surgery, which uses a 0.02 mm thread, is in practical stage. The 0.02 mm thread is not visible on 2K (i.e., a high-definition television (HDTV)) and 4K endoscopes, but it can be traced using 8K endoscopes. However, fine focus is necessary. It is very difficult to adjust the focus of 8K because it is impossible to do it with the usual tools such as view finders or small monitors. Commercial HD/4K cameras are equipped with autofocus functions. Meanwhile, professional 4K/8K cameras and 4K/8K endoscopes do not have an autofocus function. Generally, the central areas are the focal point of an autofocus function. However, in the case of 8K endoscopes, the central areas are not always the focal points. The focal depth is very deep and the focal points may change during endoscopic surgeries. Thus, the focus of the endoscope should be manually controlled by a medical doctor. Although fine focused 8K frames are extremely sharp and are useful for pathological diagnosis of still images. However, out-of-focus 8K still images cannot be used for this purpose. In this study, the total variation for an 8K endoscope still image is proposed and its validity is proven using the 8K endoscope frames.