Boundary extraction is the foundation of image recognition A method of B-spline active contours boundary extraction based on conjugate gradient vector is presented With human machine interface

it gives a B-spline curve which is close to and similar to the objective edge in shape and location Rather than evolving deformable curve with every pixel on the curve in conventional method

the proposed method evolves the curve with controlled node points which are much less than pixel points in numbers

so computational cost should be reducedThen

an additional conjugate gradient vector force is added on the evolution curve in the gradient vector field

it can make the active contours convergence to the desired edge quickly The experimental result shows that the proposed method can solve deep concave problems and is efficient in image boundary extraction