Three-dimensional image producing method and apparatus
AssigneesHitachi, Ltd., Hitachi Medical Corporation
InventorsMichio Oikawa, Koichi Sano, Yoshiaki Isobe
Life of this patent
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Abstract
A three-dimensional image producing method of determining, as display candidates, voxel data having a value exceeding a display threshold set for density, and voxel data of a specified classification selected from among voxel data classified into a plurality of display classifications, and projecting the voxel data as the display candidates onto a projection plane on the basis of predetermined display conditions to form a three-dimensional image.
Claims22
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting to a memory volume data composed of a three-dimensional array of voxel data classified beforehand into a plurality of classifications;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- setting at least one of the plurality of classifications as a display classification;
- determining, as display candidates, voxel data of the input volume data which has a value exceeding the display threshold and voxel data of the input voxel data classified into the set display classification;
- and
- projecting the voxel data as the determined display candidate onto the projection plane.
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting the volume data to a memory;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- emphasizing a change in the density of the input volume data;
- determining, as a display candidate, that voxel data of the volume data of which the edge has been emphasized and which has a value exceeding the display threshold;
- and
- projecting the voxel data determined as the display candidate onto the projection plane.
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting the volume data to a memory;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- obtaining a maximum value of voxel data on a plane perpendicular to each of coordinate axis direction which define the input volume data at a coordinate along that coordinate axis direction;
- obtaining a range of coordinates at which the maximum value of voxel data exceeds the threshold in each of the coordinate axis directions;
- determining, as a display candidate, voxel data having a value exceeding the threshold in a cuboid which has, as a range of presence in dimensions corresponding to the coordinate axis directions, the range of coordinates at which the maximum value of voxel data exceeds the threshold in each of the coordinate axis directions;
- and
- projecting the voxel data determined as the display candidate onto the projection plane.
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting the volume data to a memory;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- determining a position where the value of voxel data exceeds the threshold first by scanning the three-dimensional space sequentially from its side closer to each of points on the projection plane to its side remoter from that point on the projection plane in the direction normal to the projection plane at a wider interval than the interval of coordinates which define a position in at least one of the coordinate axis directions of a three-dimensional coordinate system set in the three-dimensional space;
- determining the position of that of the voxel data having a value exceeding the display threshold and closest to the projection plane by scanning the environment of the determined position at the same interval as the coordinates in the three-dimensional space;
- determining, as a display candidate, that of voxel data at a position remoter from the projection plane than the position closest to the projection plane and having a value exceeding the threshold;
- and
- projecting the voxel data determined as the display candidate onto the projection plane.
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting the volume data to a memory;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- determining, as a display candidate, voxel data having a value exceeding the threshold;
- setting a reflectivity and a transmittivity in each of the voxel data determined as display candidates in dependence on the value of an opacity of that voxel data which is obtained by normalization of that voxel value with the difference between the maximum possible value of that voxel data and the threshold;
- handling, as a temporary projection value, a value obtained when the rays of light reflected by a respective one of the voxel data determined as the display candidates at its set reflectivity in the three-dimensional space pass through other voxels as the display candidates at their set transmittivities to be projected onto the projection plane having the set positional relationship to the volume data;
- and
- handling the sum of the respective temporary projection values obtained for the respective voxel data as display candidates projected onto each of points on the project plane as a pixel value of the produced image.
A three-dimensional image producing method of projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising the steps of:
- inputting the volume data to a memory;
- setting a positional relationship between the projection plane and the volume data in the three-dimensional space;
- setting a display threshold for density;
- determining, as a display candidate, voxel data having a value exceeding the threshold;
- setting a reflectivity and a transmittivity in each of the voxel data determined as display candidates in dependence on the value of an opacity of that voxel data, the opacity being determined in accordance with a predetermined function of the threshold and the value of the voxel data as the indicative candidate;
- when the rays of light reflected by a respective one of the voxel data determined as the display candidates at its set reflectivity in the three-dimensional space pass through other voxels as the display candidates at their set transmittivities to be projected onto the projection plane, obtaining the projected value of the rays of light as a temporary projection value at a point on the projection plane onto which the voxel data as the display candidate is projected;
- and
- handling the sum of the respective temporary projection values obtained for the respective voxel data as display candidates projected onto each of points on the project plane as a pixel value of the produced image.
A three-dimensional image producing apparatus for projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising:
- a memory for storing volume data composed of a three-dimensional array of voxel data classified beforehand into a plurality of classifications;
- means for receiving a disposed relationship between the projection plane and the volume data in the three-dimensional space;
- means for receiving a display threshold;
- means for receiving the designation of at least one of the plurality of classifications as the designation of a display one;
- means for determining, as display candidates, voxel data of the input volume data having a value exceeding the threshold, and voxel data classified into the display classification the designation of which has been received;
- rendering means for producing an image by projecting the voxel data determined as the display candidates onto the projection plane;
- and
- display means for displaying the produced image.
A three-dimensional image producing apparatus for projecting a three-dimensional object, defined by volume data composed of a three-dimensional array of voxel data disposed in a three-dimensional space, onto a projection plane disposed in the three-dimensional space to produce an image, comprising:
- a memory for storing volume data composed of a three-dimensional array of voxel data;
- means for receiving a disposed relationship between the projection plane and the volume data in the three-dimensional space;
- means for receiving the setting of a display threshold continuously;
- means for receiving the designation of at least one of the plurality of classifications as the designation of a display one;
- means for determining, as display candidates, those of the input volume data having a value exceeding the threshold;
- rendering means for producing an image by projecting the voxel data determined as the display candidates onto the projection plane on the assumption that each of the voxel data as the display candidates has an optical characteristic depending on the value thereof;
- and
- display means for displaying the produced image.
Dependencies are inferred from the claim text.