Abstract: Accelerated filtered back projection for computed tomography image reconstruction. In an embodiment, a filtered back projection is performed on a sinogram. The back projection may comprise transitioning the sinogram to a linogram using linear interpolation, and performing an inverse Fast Hough Transform on the linogram to produce a reconstructed CT image. Filtering in the filtered back projection may use an infinite impulse response (IIR) filter.

Abstract: Real-time monitored computed tomography (CT) reconstruction for reducing a radiation does. During helical CT scanning of a target object, projections may be acquired in either a full mode which subjects the target object to a full radiation dose, or a reduced mode which subjects the target object to a reduced radiation dose (e.g., by reducing the number of projections acquired, reducing the exposure time, etc.). After a sector is acquired in the full mode, a slice of the target object that is influenced by that sector is identified, and a CT image of that slice is reconstructed using projections that have been previously acquired for that slice. When a stopping rule is satisfied based on this partial reconstruction, the full mode is switched to the reduced mode, and at least one subsequent sector is acquired in the reduced mode.

Abstract: A system for monitored tomographic reconstruction, comprising: an x-ray generator configure to generate x-ray beams for scanning an object; detectors configured to capture a plurality of projections for each scan; at least one hardware processor; and one or more software modules that, when executed by the at least one hardware processor, receive the plurality of projections from the detectors and as each of the plurality of projections is received, generate a partial reconstruction, and make a stopping decision with respect to whether or not another projection should be obtained based on a stopping problem and that defines when a reconstructed image quality is sufficient with respect to the expended cost as determined by a stopping rule.

Abstract: Computed tomography (CT) image reconstruction from polychromatic projection data. In an embodiment, polychromatic projection data is acquired using a CT system. An optimal correction value for linearization of the polychromatic projection data is determined, and the polychromatic projection data is linearized according to the determined optimal correction value. The image is then reconstructed from the linearized projection data.

Abstract: A bipolar morphological neural network may be generated by converting an initial neural network by replacing multiplication calculations in one or more convolutional layers with approximations that utilize maximum/minimum and/or addition/subtraction operations. The remaining part of the network may be trained after each convolutional layer is converted.

Abstract: Artificial intelligence using convolutional neural network with Hough Transform. In an embodiment, a convolutional neural network (CNN) comprises convolution layers, a Hough Transform (HT) layer, and a Transposed Hough Transform (THT) layer, arranged such that at least one convolution layer precedes the HT layer, at least one convolution layer is between the HT and THT layers, and at least one convolution layer follows the THT layer. The HT layer converts its input from a first space into a second space, and the THT layer converts its input from the second space into the first space. The CNN may be applied to an input image to perform semantic image segmentation, so as to produce an output image representing a result of the semantic image segmentation.

Abstract: Approximate modeling of next combined result for stopping text-field recognition in a video stream. In an embodiment, text-recognition results are generated from frames in a video stream and combined into an accumulated text-recognition result. A distance between the accumulated text-recognition result and a next accumulated text-recognition result is estimated based on an approximate model of the next accumulated text-recognition result, and a determination is made of whether or not to stop processing based on this estimated distance. After processing is stopped, the final accumulated text-recognition result may be output.

Abstract: A system for monitored tomographic reconstruction, comprising: an x-ray generator configure to generate x-ray beams for scanning an object; detectors configured to capture a plurality of projections for each scan; at least one hardware processor; and one or more software modules that, when executed by the at least one hardware processor, receive the plurality of projections from the detectors and as each of the plurality of projections is received, generate a partial reconstruction, and make a stopping decision with respect to whether or not another projection should be obtained based on a stopping problem and that defines when a reconstructed image quality is sufficient with respect to the expended cost as determined by a stopping rule.

Abstract: Text recognition in a video stream using combined recognition results with per-character weighting. In an embodiment, for each frame in a video stream, a text-recognition result is obtained and a frame weight is calculated. The text-recognition results of the frames are combined by aligning character-recognition results and calculating a character weight for each character-recognition result. At each position in the alignment, the character-recognition results are accumulated based on the character weights and frame weights to produce an accumulated text-recognition result that represents a text field in the video stream.

Abstract: Artificial intelligence using convolutional neural network with Hough Transform. In an embodiment, a convolutional neural network (CNN) comprises convolution layers, a Hough Transform (HT) layer, and a Transposed Hough Transform (THT) layer, arranged such that at least one convolution layer precedes the HT layer, at least one convolution layer is between the HT and THT layers, and at least one convolution layer follows the THT layer. The HT layer converts its input from a first space into a second space, and the THT layer converts its input from the second space into the first space. The CNN may be applied to an input image to perform semantic image segmentation, so as to produce an output image representing a result of the semantic image segmentation.

Abstract: Efficient location and identification of documents in images. In an embodiment, at least one quadrangle is extracted from an image based on line(s) extracted from the image. Parameter(s) are determined from the quadrangle(s), and keypoints are extracted from the image based on the parameter(s). Input descriptors are calculated for the keypoints and used to match the keypoints to reference keypoints, to identify classification candidate(s) that represent a template image of a type of document. The type of document and distortion parameter(s) are determined based on the classification candidate(s).

Abstract: A method for detecting holographic elements in a video stream containing images in the form of documents includes: processing of a video stream in which the document image is stabilized; constructing saturation and color tone maps; analyzing color characteristics in image regions; constructing histograms of color characteristics; estimating a change in the color characteristics at least in part based on data obtained by calculating a difference between the histograms of a current and a previous frame; constructing an integrated map of hologram presence estimates by combining calculated estimates for all video stream frames based at least in part on the estimation of the change in color characteristics; and determining final regions of the holographic elements based at least in part on the integrated map of the hologram presence estimates.