1. A method of creating a segmentation of a volume of interest in an object data set, which object data set is formatted into object data slices, in which at least two object data slices each contain a contour line defining the portion of the volume of interest present in that object data slice as a region of interest, characterized in that, the method comprises the steps of:
calculating at least one surface which cuts through each of the at least two regions of interest,
defining two curves on each of said surface which intersect with the contour lines,
arranging for those curves to define the portion of the volume of interest present in said surface,
calculating on the remaining object data slices a contour line which includes those points on the curves which intersect with that object data slice.
2. A method of creating a segmentation of a volume of interest in an object data set as claimed in claim 1, characterized in that the method of calculating the at least one surface comprises the steps of:
calculating a line which intersects with each region of interest in the object data slices,
calculating the at least one surface in such a way that each such surface contains that line.
3. A method of creating a segmentation of a volume of interest in an object data set as claimed in claim 2, characterized in that the method of defining the two curves on each surface which intersect with the contour lines comprises the steps of:
assigning control points at the intersection of the contour lines with each said surface,
defining each curve as a curve which intersects the control points on one side of the line in each of said surfaces.
4. A method of creating a segmentation of a volume of interest in an object data set as claimed in claim 2, characterized in that the method of calculating the line comprises the steps of:
calculating the center of gravity of at least two of the contour lines in the object data slices,
calculating the line in such a way that it connects up each calculated center of gravity.
5. A method of creating a segmentation of a volume of interest in an object data set as claimed in claim 2, in which further there is more than one surface which cuts through each of the at least two regions of interest, and these surfaces are calculated to be angularly ranged in an evenly spaced manner around the line.
6. A method of creating a segmentation of a volume of interest in an object data set as claimed in claim 1 characterized in that there is an adjustable number of surfaces.
7. A computer program arranged to segment a volume of interest in an object data set, which object data set is formatted into object data slices, in which at least two object data slices each contain a contour line defining the portion of the volume of interest present in that object data slice as a region of interest, characterized in that, the computer program is arranged to:
calculate at least one surface which cuts through each of the at least two regions of interest,
calculate two curves on each of said surface which intersect with the contour lines,
arrange for those curves to define the portion of the volume of interest present in said surface,
calculate on the remaining object data slices a contour line which includes those points on the curves which intersect with that object data slice.
8. A work station arranged to segment a volume of interest in an object data set, which object data set is formatted into object data slices, in which at least two object data slices each contain a contour line defining the portion of the volume of interest present in that object data slice as a region of interest, characterized in that, the work station is arranged to:
calculate at least one surface which cuts through each of the at least two regions of interest,
calculate two curves on each of said surface which intersect with the contour lines,
arrange for those curves to define the portion of the volume of interest present in said surface,
calculate on the remaining object data slices a contour line which includes those points on the curves which intersect with that object data slice.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A screen comprising a screen sheet including
a lens array having a plurality of element lenses arranged in a two-dimensional plane on the front side of the screen,
a plurality of reflection surfaces disposed on the backside of the lens array, the plurality of reflection surfaces inclined to the two-dimensional plane, and
a plurality of scattering portions that scatter the light directed from the plurality of reflection surfaces toward the front side of the screen,
wherein at least one of the plurality of element lenses is a combined lens comprised of a set of two lens portions offset from each other obtained by relatively shifting optical axes of the lens portions, and
the reflection surfaces correspond to the respective combined lenses.
2. The screen according to claim 1,
wherein the lens array includes a plurality of cylindrical lenses as the plurality of element lenses, and the lens array is comprised of a lenticular lens in which the plurality of cylindrical lenses are arranged perpendicular to the generating line of the cylindrical lenses in the side of the screen.
3. The screen according to claim 1,
wherein the optical axis of the lens portion of the two lens portions that is located on one side in which the angle of incidence of projection light with respect to the two-dimensional plane is larger is located closer to the one side than the optical axis of the lens portion located on the other side, which is the opposite side to the one side.
4. The screen according to claim 1,
wherein the optical axes of the two lens portions are shifted in opposite directions from the center of the combined lens.
5. The screen according to claim 4,
wherein the optical axes of the two lens portions are equally spaced apart from the center of the combined lens.
6. The screen according to claim 1,
wherein the relative amount of shift of the optical axis of each of the two lens portions is within a range from 112 to \u2153 a single pitch that corresponds to one of the combined lenses in the lens array.
7. The screen according to claim 1,
wherein the center of the reflection surface corresponding to the combined lens is located, with reference to the center of the combined lens, on one side in which the angle of incidence of projection light with respect to the two-dimensional plane is larger.
8. The screen according to claim 1,
wherein the side cross-sectional shape of at least one of the two lens portions includes a non-arcuate shape whose curvature becomes smaller in portions closer to the periphery close to an adjacent lens.
9. The screen according to claim 1,
wherein the screen sheet includes a first area in which in the lens array, projection light exits from an element lens different from the element lens on which the projection light is incident and a second area in which in the lens array, projection light exits from the same element lens as the element lens on which the projection light is incident, and
the lens array includes the combined lens in the second area.
10. The screen according to claim 1, further comprising a light-absorbing plane made of a light-absorbing material at least on the portions of the backside of the lens array that are located around the reflection surfaces.
11. The screen according to claim 1,
wherein the lens array has an anti-reflection coating thereon.
12. The screen according to claim 2,
wherein the lenticular lens can be rolled and has a structure in which the longitudinal direction of the plurality of cylindrical lenses is oriented along the direction of the axis around which the lenticular lens is rolled.
13. A projection system comprising:
the screen according to claim 1; and
an image projection apparatus that projects a projected image on the screen.