Endoscopic navigation method and endoscopic navigation system

An endoscopic navigation system, comprising:

• a photographic device configured to photograph a colon interior;
• an image classifying module configured to retrieve an image photographed by the photographic device, and perform image classification to determine whether the image is usable, wherein the image classifying module is configured to perform the steps of:
• when a ratio of pixels of the image with luminance values smaller than a first predetermined luminance value to the image size, is larger than a predetermined ratio value, the image is classified as a very dark image;
• when a ratio of pixels of the image with luminance values larger than a second predetermined luminance value to the image size, is larger than the predetermined ratio value, the image is classified as a very bright image;
• when a ratio of pixels of the image with hue values smaller than a first predetermined hue value or larger than a second predetermined hue value and saturation values larger than a predetermined saturation value to the image size, is larger than the predetermined ratio value, the image is classified as a double-exposure image;
• and
• when the image is not classified as a very dark image, a very bright image or a double-exposure image, the image is classified as a clear image;
• a first image process module configured to perform a first image process on the image to filter out dark areas of the image to produce a first processed image, perform a first determination procedure to identify the dark areas of the first processed image, and produce a first result image for indicating lumen direction according to the dark areas;
• a second image processing module configured to perform a second image process on the image to produce a second processed image, perform a second determination procedure to filter out fold curves to identify the fold curves of the second processed image and produce a second result image for indicating lumen direction according to the fold curves;
• and
• a display device configured to display the first result image or the second result image to assist a user in operating the photographic device in the lumen.