摘要:
There is described a method for generating a 2-D image of a 3-D object represented by a volume data set comprising a multiplicity of data points each having an opacity value. A plurality of notional rays are cast through the 3-D object and for each ray, a ray path is divided into a plurality of base sampling intervals defined by data points on the path. If it is determined that a difference in opacity values across a base sampling interval can become greater than a pre-determined value, successively smaller sampling regions are generated within the base sampling interval until it is determined that a difference in opacity values across each generated smaller sampling interval in the base interval is less than the pre-determined threshold. Values indicative of an interaction between the ray and the 3-D object in the sampling intervals along the path are accumulated using a direct volume rendering procedure to determine a pixel value in the 2-D image.
摘要:
A method, computer program and device for creating a viewing protocol for medical images is described. At least a first site of interest is identified in a medical imaging data set captured from the patient. Patient record data or computer assisted detection information can be used to identify the site of interest, which may be a potential lesion. A viewing protocol for displaying medical images to a user is planned. The viewing protocol includes a viewing path along which an image of the site of interest will be displayed. The viewing protocol also includes a trigger associated with the site of interest. When the trigger event is encountered the dynamic mode of image display is reconfigured to dynamically highlight the site of interest. The viewing protocol can then be used to control the display of images so as to provide, for example, a virtual endoscope.
摘要:
Medical imaging modalities generate increasingly more and very large three-dimensional data sets. According to an exemplary embodiment of the present invention, a three-dimensional data set of an object of interest is interactively visualized with a varying sampling rate in an image. Advantageously, a focus area may be moved by a user interactively during rendering, wherein the sampling rate of a particular part of the image is defined by its relative position to the focus area. Advantageously, this may allow for an improvement of an overall rendering performance.
摘要:
In real-time three-dimensional imaging the choice of the visualization method and orientation is crucial for intervention success. The key question is what to ignore and what to show in real-time applications, where user control is not appropriate. The invention addresses this problem by visualizing an intervention (caused by a user) to an object of interest without the requirement of an interactive input by the user. Advantageously, according to an exemplary embodiment of the present invention, parameters for a visualization procedure are automatically chosen during data acquisition which may allow for an efficient tracking of the actual orientation and relative position of the structure with respect to the object of interest.
摘要:
Sampling frequency of a ray casting for generating a projection image is varied in dependence of information derived from a 3D volume data during rendering. Furthermore, an interpolation is performed for skipped pixels for which no ray casting was performed in the projection image, based on this information.
摘要:
High frequency signals cannot be reconstructed properly from sampled data if the sampling frequency lies below the Nyquist rate. The invention addresses this problem by choosing few additional sample points along a trajectory intersecting the region comprising the high frequency signals, such as an edge. Intermediate rendering data is used to determine the additional sample points. Therefore, according to an exemplary embodiment of the present invention, 4 adaptively chosen sample points per pixel may provide a visual quality comparable to 16 times super-sampling, but at a much lower computational cost.
摘要:
A method allowing display of time-varying merged high resolution and low resolution image data with a smooth frame rate. In one embodiment the high resolution data is structural image data and the low resolution image data is functional image data. The functional image data is gathered (20) into groups and each group is rendered and merged (24) together. The merged images produced are then stored (28) in a First In First Out (FIFO) buffer for display. While the merged images are displayed the next set of functional image data is merged and rendered and supplied to the FIFO buffer, allowing a smooth frame rate to be achieved. A computer program and a medical imaging apparatus using the method are also disclosed.
摘要:
The present invention relates to direct volume rendering based on a light model applied to a 3D array of information data samples. Gradients are first estimated for the individuals samples, and a simple shading is done on the samples with low gradient, i.e. homogenous areas.
摘要:
High frequency signals cannot be reconstructed properly from sampled data if the sampling frequency lies below the Nyquist rate. The invention addresses this problem by choosing few additional sample points along a trajectory intersecting the region comprising the high frequency signals, such as an edge. Intermediate rendering data is used to determine the additional sample points. Therefore, according to an exemplary embodiment of the present invention, 4 adaptively chosen sample points per pixel may provide a visual quality comparable to 16 times super-sampling, but at a much lower computational cost.
摘要:
Because of the increasing size of digital images available, an interactive rendering speed at a high display quality continues to be a challenging task. According to the present invention, a sampling frequency of a ray casting for generating the projection image is varied in dependence of information derived from the 3D volume data during rendering. Furthermore, an interpolation is performed for skipped pixels for which no ray casting was performed in the projection image, based on-this information. Advantageously, the present invention allows for an improved image quality, while reducing a computation time required to generate an output image.