Radiation imaging system for inspection of items having an uncertain pose and method therefor

Computer-implemented method for inspecting a plurality of items with a radiation imaging system, wherein the items are mounted on a holder comprising a plurality of mounts that are rotationally coupled such that each item mounted to one of the mounts is rotated simultaneously to an equivalent degree, the method comprising the steps of:

• receiving at least one projection image containing the plurality of items with an uncertain pose acquired at a first zoom level;
• estimating a plurality of poses corresponding to the plurality of items;
• wherein the pose estimation comprises fitting a numerical model to the plurality of items on said image, wherein said numerical model comprises one or more simulations virtually representing the item at one or more poses, and calculating a pose estimation error representing fitting accuracy of the numerical model for the plurality of items;
• instructing the radiation imaging system to simultaneously reposition the plurality of items to a different pose based on the pose estimation error, wherein the repositioning includes at least a rotation along each mount's central axis such that the pose of the items is coupled;
• receiving a projection image containing the plurality of items at the different pose and iteratively refining the pose estimation until the pose estimation error for the plurality of items is within an accuracy acceptance criterion;
• instructing the radiation imaging system to simultaneously reposition the plurality of items for acquiring a projection image on at least a second zoom level that is higher than the zoom level of the pose estimation;
• instructing the radiation imaging system to reposition the plurality of items based the corresponding estimated pose;
• and,
• receiving a plurality of projection images of the plurality of items at the second zoom level.

Radiation imaging system for inspecting a plurality of items, comprising:

• a radiation imaging device comprising a radiation source and a detector configured for acquiring a projection image as image data;
• a holder comprising a plurality of mounts for mounting the plurality of items at an uncertain pose, wherein the mounts are rotationally coupled such that each item mounted to one of the mounts is rotated simultaneously to an equivalent degree, and an actuator configured for simultaneously repositioning the plurality of items to a plurality of poses, wherein the simultaneous repositioning includes at least a simultaneous rotation along each mount's central axis;
• a control system, operatively connected to the imaging device and holder, and configured to
• estimate a plurality of poses corresponding to the plurality of items based on image data acquired by the imaging device;
• wherein the image data comprises at least one projection image containing the plurality of items acquired at a first zoom level;
• wherein the pose estimation comprises fitting a numerical model to the plurality of items on said image, wherein the numerical model comprises one or more simulations virtually representing the item at one or more poses, and calculating a pose estimation error representing the fitting accuracy of the numerical model for the plurality of items;
• iteratively refine the pose estimation by instructing the holder to simultaneously reposition the plurality of items to a different pose based on the pose estimation error, wherein the simultaneous repositioning includes at least a simultaneous rotation along each mount's central axis such that the poses of the items are coupled, and repeating the pose estimation until the pose estimation error for the plurality of items is within an acceptance criterion;
• and,
• inspect the plurality of items to determine an item characteristic based on second image data acquired by the imaging device;
• whereby the item inspection comprises instructing the holder to simultaneously reposition the plurality of items to at least a second zoom level that is higher than the zoom level of the pose estimation;
• wherein the second image data comprises a plurality of projection images of the plurality of items at the second zoom level and the corresponding estimated pose for the item inspection.