摘要:
A system for displaying sets of surface cubes with gradient vertex vectors first employs a pointer table constructed to order the surface cubes so as to generally cause a row by row and layer by layer ordering during model creation. During display, a viewpoint is selected and a scan controller causes cubes to be displayed according to this order of the pointer table. A test backprojection of cubes to image plane is performed to determine which pixels will be impinged by the cubes. For pixels which have not been updated, or pixels which have been updated by a less superficial cube than the current cube, projection rays are created through the center of impinged pixels in a direction opposite that of the backprojection. An intersection point of the ray with a surface within a current cube is determined. The data value and gradient vectors for the current cube are interpolated at this intersection point. These interpolated vector and value are then rendered to produce and image with less distortion and with less processing complexity.
摘要:
A computer modeling and visualization system employs both 3D visual modeling and force feedback through a haptic device consistent with the visual display of the computer model. Force, or haptic, interaction is employed for exploring computer models. Point contact force equations were created for quickly computing forces directly from a model data which are provided to the haptic device, causing it to apply that force to an operator. The force equations employed are consistent with isosurface and volume rendering, providing a strong correspondence between visual and haptic rendering. The method not only offers the ability to see and feel the volumetric model but allows interactive modification and display of the model.
摘要:
A system and method for ascertaining the identity of an object within an enclosed article. The system includes an acquisition subsystem, a reconstruction subsystem, a computer-aided detection (CAD) subsystem, and an alarm resolution subsystem. The acquisition subsystem communicates view data to the reconstruction subsystem, which reconstructs it into image data and communicates it to the CAD subsystem. The CAD subsystem analyzes the image data to ascertain whether it contains any area of interest. A feedback loop between the reconstruction and CAD subsystems allows for continued, more extensive analysis of the object. Other information, such as risk variables or trace chemical detection information may be communicated to the CAD subsystem to dynamically adjust the computational load of the analysis.
摘要:
A method and an apparatus for allowing the operator of an ultrasound imaging system to switch between two-dimensional slices and three-dimensional projections in such a way that it is easy for the operator to visualize the relationship of the two-dimensional slice to the three-dimensional anatomy. In a "volume rotate" mode, the display screen displays an orientation box along with a three-dimensional projected image generated from a defined data volume. The orientation box provides a visual indication of the shape and orientation of that defined data volume. In a "cut plane" mode, a movable polygon representing a selected two-dimensional slice is displayed inside a stationary orientation box. The polygon provides a visual indication of the orientation and position of the slice relative to the defined data volume. In a "cut plane rotate" mode, a stationary polygon representing a selected two-dimensional slice is displayed inside a rotatable orientation box.
摘要:
A method for segmenting an input volume in accordance with at least one selected characteristic comprises the steps of casting a plurality of rays along a plurality of views of the input volume, identifying regions corresponding to the selected characteristic within each ray, and processing the identified regions to generate an output volume indicating regions having the selected characteristic.
摘要:
The axis of rotational transducer array scans, because of imperfect transducer array assembly, may have two orthogonal offsets relative to the geometric center of the transducer array. Without knowledge of these offsets, it is not possible to convert rotational transducer scan data into a rectilinear (Euclidean) coordinate system, as is necessary for three-dimensional processing. Using spatial coherency between appropriate scan lines in different rotational transducer scans, the horizontal and vertical rotational offsets are calculated. These offsets are then utilized in converting the data to a rectilinear coordinate system for three-dimensional processing.
摘要:
A technique is disclosed for generating variance data and a variance map from measured projection data acquired from a tomography system. The method comprises accessing the measured projection data from the tomography system. The method further comprises generating the variance map from the measured projection data and displaying, analyzing or processing the variance map. The variance data is determined based upon a statistical model from measured image data, and may be used for image analysis, data acquisition, in computer aided diagnosis routines, and so forth.
摘要:
A method for processing medical images for use in the detection and diagnosis of disease comprises classifying regions of interest within the medical images based on a hierarchy of anatomical models and signal models of signal information of an image acquisition device used to acquire the medical images. The anatomical models are derived to be representative of anatomical information indicative of a given disease. A computer-aided system for use in the diagnosis and detection of disease comprises an image acquisition device for acquiring a plurality of image data sets and a processor adapted to process the image data sets. The processor is adapted to classify selected tissue types within the image data sets based on a hierarchy of signal and anatomical models and the processor is further adapted to differentiate anatomical context of the classified tissue types for use in the diagnosis and detection of disease.
摘要:
A system and a method for detecting an object, such as an explosive device or material, located within a closed article, such as a piece of luggage or a parcel. The system includes an acquisition subsystem for acquiring information pertaining to a specific object, a reconstruction subsystem for reconstructing acquired information pertaining to the specific object into image data, and a computer-aided detection subsystem adapted for identifying the specific object through the use of differential operators. The method includes obtaining image data of the one object, computing a differential operator for each voxel of the image data, computing eigenvalues and eigenvectors for each of the voxels, and computing a scalar function of the eigenvalues to ascertain whether each of the voxels represents a portion of the one object.
摘要:
The present invention is directed toward providing interactive haptic collision detection between a stationary and a moving object in a virtual reality environment. A user grasps the arm of a haptic device and manipulates an object as viewed on a virtual reality display. As any portion of the manipulated object comes too close to the surface of the stationary object, the haptic device imposes feedback forces against the user's efforts that increase in magnitude as the user manipulates the object beyond a force boundary proximate to the surface of the stationary object. The feedback forces are applied directionally in line with the shortest path between the surfaces at risk of collision. Several measures can be implemented by the user to reduce the computation load involved in constantly comparing the distances between points on the surface of the movable object and points on the surface of the stationary object without seriously compromising the collision detection and avoidance functions of the system. Furthermore, while the invention provides for up to six degrees of freedom for manipulating objects and providing haptic feedback, the system also accommodates three degrees of haptic freedom and feedback, with the additional three degrees of rotational feedback being provided visibly or audibly.