Method and device for the X-ray inspection of products, in particular foodstuffs

A method for X-ray inspection of products, the method including:

• (a) transmitting X-radiation with a spectral range through a subject product, the subject product being a first product type which is defined as including at least a first component and a second component, the first component having an X-radiation absorption coefficient which is different from an X-radiation absorption coefficient of the second component;
• (b) detecting portions of the X-radiation which have passed through the subject product, the detecting being performed with a spectrally resolving X-radiation detector along a number of adjacent pixels such that the X-radiation detected at each pixel is spectrally resolved into a number of energy channels with each energy channel assigned the quanta of X-radiation detected at that pixel in an energy range defined for that energy channel to produce a respective spectral value at each respective energy channel for that pixel, the detected X-radiation comprising image data which for each respective pixel includes a respective spectral value for selected or all energy channels of that pixel, or a respective total spectral value for each of one or more groups of adjacent energy channels of that pixel, or both a respective total spectral value for each of one or more groups of adjacent energy channels of that pixel and a respective spectral value for one or more energy channels not included in the one or more groups of adjacent energy channels;
• and
• (c) assigning a mapping rule to all pixels or to groups of one or more pixels of the number of adjacent pixels, the mapping rule being determined for the first product type and mapping spectral values and total spectral values included in the image data for the respective pixel to a total image value of an image point of a total image for the subject product.

A device for X-ray inspection of products, the device including:

• (a) a radiation-generating device with at least one X-ray source for generating X-radiation with a spectral range;
• (b) a spectrally resolving X-ray detector operable for detecting the X-radiation that has passed through a subject product at each of a number of adjacent pixels such that the X-radiation detected at each pixel is spectrally resolved into a number of energy channels with each energy channel assigned the quanta of X-radiation detected at that pixel in an energy range defined for that energy channel to produce a respective spectral value at each respective energy channel defined for that pixel, the detected X-radiation comprising image data which for each respective pixel includes a respective spectral value for selected or all energy channels of that pixel, or a respective total spectral value for each of one or more groups of adjacent energy channels of that pixel, or both a respective total spectral value for each of one or more groups of adjacent energy channels of that pixel and a respective spectral value for one or more energy channels not included in the one or more groups of adjacent energy channels, and
• (c) an evaluation and control unit, operatively connected to receive the image data and for assigning a mapping rule to all pixels or to groups of one or more pixels of the number of adjacent pixels, the mapping rule being determined for a first product type and mapping spectral values and total spectral values included in the image data for the respective pixel to a total image value of an image point of a total image for the subject product.