Abstract: Methods and systems for sample imaging via two-pass light-field reconstruction. In an exemplary method, a light-field image of a sample may be captured in a light-field plane. The light-field image may be forward-projected computationally to each of a plurality of z-planes in object space to generate a set of forward-projected z-plane images. Backward-projections computationally to the light-field plane of the same xy-region in object space from each z-plane image may be compared with the light-field image, to determine a respective degree of correspondence between the backward-projected xy-region from each of the z-plane images and the light-field image. For each different xy-region, at least one of the forward-projected z-plane images may be selected to contribute data for the different xy-region in a 2D or 3D object-space image of the sample.

Abstract: Methods of calibrating a light-field imaging system, a light-field imaging system to perform the calibration methods, a calibration target for the calibration methods, and methods of projecting a light-field image into object space with a calibrated light-field imaging system. An exemplary calibration method is performed with a light-field imaging system including a microlens array (72) and an image sensor (76). A z-stack of light-field images of a calibration target may be captured using the image sensor, while the calibration target is on the stage and located at a plurality of different z-positions. A total magnification of the imaging system and a microlens magnification of the microlens array may be determined from each light-field image of the z-stack.

Abstract: Methods of calibrating a light-field imaging system, a light-field imaging system to perform the calibration methods, a calibration target for the calibration methods, and methods of projecting a light-field image into object space with a calibrated light-field imaging system. An exemplary calibration method is performed with a light-field imaging system including a microlens array and an image sensor. A z-stack of light-field images of a calibration target may be captured using the image sensor, while the calibration target is on the stage and located at a plurality of different z-positions. A total magnification of the imaging system and a microlens magnification of the microlens array may be determined from each light-field image of the z-stack.

Abstract: Methods of calibrating a light-field imaging system, a light-field imaging system to perform the calibration methods, a calibration target for the calibration methods, and methods of projecting a light-field image into object space with a calibrated light-field imaging system. An exemplary calibration method is performed with a light-field imaging system including a microlens array and an image sensor. A z-stack of light-field images of a calibration target may be captured using the image sensor, while the calibration target is on the stage and located at a plurality of different z-positions. A total magnification of the imaging system and a microlens magnification of the microlens array may be determined from each light-field image of the z-stack.

Abstract: A method operates an x-ray system for examining an object. In order to optimize the operation of an x-ray system, in particular the dose regulation and/or the image processing, the following method steps are performed. Radiation is passed through the object to be examined and a number of fluoroscopic images of the object are generated. A relevant image region of a fluoroscopic image is selected by a user of the x-ray system. An image-based dose regulation of the radiation dose used for passing radiation through the object is carried out using the selected image region and/or image processing is carried out using the selected image region.

Abstract: A method operates an x-ray system for examining an object. In order to optimize the operation of an x-ray system, in particular the dose regulation and/or the image processing, the following method steps are performed. Radiation is passed through the object to be examined and a number of fluoroscopic images of the object are generated. A relevant image region of a fluoroscopic image is selected by a user of the x-ray system. An image-based dose regulation of the radiation dose used for passing radiation through the object is carried out using the selected image region and/or image processing is carried out using the selected image region.