Multi-energy-spectrum X-ray imaging system and method of substance identification of item to be inspected by using the same

A method of substance identification of an item to be inspected using a multi-energy-spectrum X-ray imaging system, the method comprising:

• acquiring a transparency related vector consisting of transparency values of the item to be inspected in N energy regions, wherein N is greater than 2;
• and
• determining the item to be inspected based on the transparency related vector,
• wherein the determining the item to be inspected based on the transparency related vector comprises:
• mapping the transparency related vector and transparency related vectors stored in the system consisting of N transparency mean values of multiple kinds of items with multiple thicknesses in the N energy regions into a two-dimensional plane by using a non-linear dimension reduction algorithm, so as to acquire a mapping point of the transparency related vector of the item to be inspected in the two-dimensional plane and a set of mapping points of the transparency related vectors of the multiple kinds of items in the two-dimensional plane, respectively;
• determining one of the set of mapping points which is closest to the mapping point;
• and
• identifying the item to be inspected as the one of the multiple kinds of items corresponding to the closest point.

A method of substance identification of an item to be inspected using a multi-energy-spectrum X-ray imaging system, the method comprising:

• acquiring a transparency related vector consisting of transparency values of the item to be inspected in N energy regions, wherein N is greater than 2;
• and
• determining the item to be inspected based on the transparency related vector;
• wherein the determining the item to be inspected based on the transparency related vector comprises:
• selecting one or more of the N energy regions as reference energy regions;
• acquiring respective N transparency values of the item to be inspected in the N energy regions based on the transparency related vector;
• calculating a reference transparency value based on the transparency values of the item to be inspected in the one or more energy regions which are selected as the reference regions;
• calculating a relative mass attenuation coefficient value of the item to be inspected in the N energy regions based on the reference transparency value and the N transparency values;
• determining one of the multiple kinds of items having a relative mass attenuation coefficient value closest to the relative mass attenuation coefficient value, and identifying the item to be inspected as the determined item.

A multi-energy-spectrum X-ray imaging system, comprising:

• an X-ray source configured to generate an X-ray;
• a detector configured to receive the X-ray which is emitted from the X-ray source and is transmitted through or scattered by an item to be inspected and convert the received X-ray into an output signal;
• a processor configured to execute program instructions to be operable to
• acquire, based on the output signal, a transparency related vector consisting of transparency values of the item to be inspected in N energy regions, wherein N is greater than 2;
• and
• determine the item to be inspected based on the transparency related vector;
• and
• a memory configured to store the program instructions;
• wherein the processor is further configured to determine the item to be inspected based on the transparency related vector by:
• calculating distances between the transparency related vector and transparency related vectors stored in the system consisting of N transparency mean values of multiple kinds of items with multiple thicknesses in the N energy regions;
• and
• determining a first atomic number and a first thickness of the item corresponding to the minimum distance and a second atomic number and a second thickness of an item corresponding to the next minimum distance;
• determining an atomic number and a thickness of the item to be inspected by using a linear interpolation algorithm based on the first and second atomic numbers and the first and second thicknesses;
• and
• determining a kind of the item to be inspected based on the atomic number and the thickness of the item to be inspected.

A multi-energy-spectrum X-ray imaging system, comprising:

• an X-ray source configured to generate an X-ray;
• a detector configured to receive the X-ray which is emitted from the X-ray source and is transmitted through or scattered by an item to be inspected and convert the received X-ray into an output signal;
• a processor configured to execute program instructions to be operable to
• acquire, based on the output signal, a transparency related vector consisting of transparency values of the item to be inspected in N energy regions, wherein N is greater than 2;
• and
• determine the item to be inspected based on the transparency related vector;
• and
• a memory configured to store the program instructions,
• wherein the processor is further configured to determine the item to be inspected based on the transparency related vector by:
• mapping the transparency related vector and transparency related vectors stored in the system consisting of N transparency mean values of multiple kinds of items with multiple thicknesses in the N energy regions into a two-dimensional plane by using a non-linear dimension reduction algorithm, so as to acquire a mapping point of the transparency related vector of the item to be inspected in the two-dimensional plane and a set of mapping points of the transparency related vectors of the multiple kinds of items in the two-dimensional plane, respectively;
• determining one of the set of mapping points which is closest to the mapping point;
• and
• identifying the item to be inspected as the one of the multiple kinds of items corresponding to the closest point.

A multi-energy-spectrum X-ray imaging system, comprising:

• an X-ray source configured to generate an X-ray;
• a detector configured to receive the X-ray which is emitted from the X-ray source and is transmitted through or scattered by an item to be inspected and convert the received X-ray into an output signal;
• a processor configured to execute program instructions to be operable to
• acquire, based on the output signal, a transparency related vector consisting of transparency values of the item to be inspected in N energy regions, wherein N is greater than 2;
• and
• determine the item to be inspected based on the transparency related vector;
• and
• a memory configured to store the program instructions,
• wherein the processor is further configured to determine the item to be inspected based on the transparency related vector by:
• selecting one or more of the N energy regions as reference energy regions;
• acquiring respective N transparency values of the item to be inspected in the N energy regions based on the transparency related vector;
• calculating a reference transparency value based on the transparency values of the item to be inspected in the one or more energy regions which are selected as the reference regions;
• calculating a relative mass attenuation coefficient value of the item to be inspected in the N energy regions based on the reference transparency value and the N transparency values;
• and
• determining one of the multiple kinds of items having a relative mass attenuation coefficient value closest to the relative mass attenuation coefficient value, and identifying the item to be inspected as the determined item.