Endoscopic imaging system making it possible to detachably attach expansion unit having external expansion facility and add expansion facility for improving capability of system

An endoscopic imaging system, comprising:

• an imaging device for imaging an object inside a body cavity;
• a digital signal converter for converting an image signal sent from said imaging device into a digital signal;
• a signal processor for processing said digital signal sent from said digital signal converter;
• a discriminating signal appending circuit for appending a discrimination signal to said digital signal processed by said signal processor;
• a compression circuit for determining a level of compressibility according to said discrimination signal appended by said discriminating signal appending circuit, and for compressing said digital signal processed by said signal processor;
• and
• a recording unit for recording said digital signal compressed by said compression circuit on a recording medium.