Method and system for generating a 3D image of a body shape
A method for generating a 3D image of a body shape includes obtaining a set of far-field patterns of electromagnetic waves from a given body shape of a human or animal, establishing a one-to-one correspondence between the body shape and the set of far-field patterns of electromagnetic waves, representing the far-field patterns as a shape generating vector, mapping a vector of characteristic parameters to the shape generating vector, producing a body generation model by taking the vector of characteristic parameters and the shape generating vector as input and output data to form a training dataset for machine learning, specifying a characteristic vector of an unknown geometric body shape and obtaining a shape generating vector of the unknown geometric body shape based on the body generation model, and reconstructing the unknown geometric body shape based on the shape generating vector.
1. A method for generating a 3D image of a body shape, implemented by a processor, comprising the steps of:
A. obtaining a set of far-field patterns of electromagnetic waves from a given body shape of a human or animal by collecting electromagnetic far-field patterns radiated from physical means, the physical means comprising a body shape model;
B. establishing a one-to-one correspondence between the body shape and the set of far-field patterns of electromagnetic waves;
C. representing the far-field patterns as a shape generating vector;
D. mapping a vector of characteristic parameters to the shape generating vector;
E. producing a body generation model by taking the vector of characteristic parameters and the shape generating vector as input and output data to form a training dataset for machine learning;
F. specifying a characteristic vector of an unknown geometric body shape and obtaining a shape generating vector of the unknown geometric body shape based on the body generation model;
G. obtaining far-field patterns corresponding to the shape generating vector of the unknown geometric body shape; and
H. reconstructing the unknown geometric body shape based on the obtained far-field patterns by an inverse scattering algorithm governed by a Maxwell system,
wherein the body shape comprises a stationary or moving body shape,
wherein, if the body shape is the moving body shape, the Maxwell system is taken to be time-dependent with a moving scatterer, and
wherein the set of far-field patterns of electromagnetic waves comprises electromagnetic spectral data which encodes a color of a scattering object.
2. The method of claim 1 , wherein step B comprises establishing the one-to-one correspondence between the body shape and the set of far-field patterns of electromagnetic waves by treating the body shape as a scattering object.
3. The method of claim 1 , wherein step B comprises representing the far-field patterns through the use of vectorial spherical harmonics.
4. The method of claim 3 , wherein step B is based on Fourier theory, and the shape generating vector consists of corresponding Fourier coefficients of the far field patterns.
5. The method of claim 1 , wherein step B comprises establishing the one-to-one correspondence between the body shape and the set of far-field patterns of electromagnetic waves by treating the body shape as a perfect conductor.
6. The method of claim 1 , wherein step E further comprises training the body generation model using the training dataset by an artificial neural network.
7. The method of claim 6 , wherein the artificial neural network comprises a convolution neural network (CNN).
8. The method of claim 1 , wherein if the body shape is the stationary body shape, the Maxwell system is taken to be time-harmonic with frequencies to be a visible electromagnetic spectrum.
9. The method of claim 1 , wherein the characteristic parameters comprise gender, height, weight, arm span, waist girth, neck girth, abdomen girth, body mass index (BMI), muscle degree, and/or motion trajectory.
10. A processor configured to implement the method of claim 1 .
11. A system for generating a 3D image of a body shape, comprising:
a processor configured to implement the method of claim 1 ;
an input unit configured to input characteristic parameters of a body shape; and
a display unit configured to present the 3D image of the body shape reconstructed by the processor.