A non-contact measuring instrument based on image detection technology is developed to measure the fiber ferrule inner hole geometry parameter.The fiber ferrule is fixed on the micro-platform

and the magnified image of the inner hole is recorded by a CCD camera

transferred by a digital image grabber into a computer.Then the image is pre-processed and the edge is detected with Canny algorithm through system software.According to further analysis and calculation with parameter transformative template and other algorithm

several parameters of the fiber ferrule inner hole are obtained.The measuring instrument can be used in improving the productivity of fiber ferrule.