Image processing apparatus, method of controlling image processing apparatus and non-transitory computer-readable storage medium

1. An image processing apparatus, comprising:

an obtaining unit configured to obtain, from a three-dimensional image, information that represents a region of interest;

a changing unit configured to change a projection direction of the three-dimensional image;

a determining unit configured to determine a parameter such that a thickness, in which the region of interest is included in the changed projection direction, represents a range sandwiched by two planes, in contact with the region of interest, orthogonal to the changed projection direction; and

a projecting unit configured to generate a projection image by applying projection processing to the three-dimensional image using the parameter determined by the determining unit.

2. The apparatus according to claim 1 , wherein the determining unit determines the parameter such that the thickness represents a range resulting from adding a predetermined distance to the range that sandwiches the entirety of the region of interest by the two planes as the parameter that indicates the thickness.

3. An image processing apparatus, comprising:

an obtaining unit configured to obtain, from a three-dimensional image, information that represents a region of interest;

a changing unit configured to change a projection direction of the three-dimensional image;

a setting unit configured to set a reference plane that is a plane orthogonal to the changed projection direction;

a determining unit configured to determine a parameter such that a thickness represents a range obtained by setting a distance in the changed projection direction from the reference plane to a furthest position of the region of interest; and

a projecting unit configured to generate a projection image by applying projection processing to the three-dimensional image using the parameter determined by the determining unit.

4. The apparatus according to claim 3 , wherein the determining unit, (a) in a case where the region of interest includes the reference plane, determines the parameter such that the thickness represents a range in which the region of interest is present along the changed projection direction, and (b) in a case where the region of interest does not include the reference plane, determines the parameter such that the thickness represents a range obtained by setting, on both sides of the reference plane, a range from the reference plane to a furthest position of the region of interest.

5. The apparatus according to claim 3 , wherein, in a case where the region of interest does not include the reference plane, the determining unit translates the reference plane so that the reference plane passes through the region of interest.

6. The apparatus according to claim 5 , wherein, if a distance between the reference plane and the region of interest exceeds a predetermined distance, the determining unit translates the reference plane so that the reference plane passes through the inside of the region of interest.

7. The apparatus according to claim 3 , wherein, if there are a plurality of regions of interest, the thickness is determined for the region of interest closest to the reference plane.

8. The apparatus according to claim 3 , wherein, in a case where the three-dimensional image is rotated in accordance with the projection direction, the setting unit sets the reference plane based on the center position of the three-dimensional image, the position of the reference point, and the projection direction.

9. The apparatus according to claim 1 , wherein the information representing the region of interest is a set of voxels determined as belonging to the region of interest.

10. The apparatus according to claim 1 , wherein the shape of the region of interest is a polyhedron, a sphere, or a prolate spheroid that surrounds a region of interest obtained from the three-dimensional image.

11. The apparatus according to claim 1 , wherein the projection processing is one of ray summation, maximum intensity projection and minimum intensity projection.

12. The apparatus according to claim 1 , further comprising a display control unit configured to cause the projection image generated by the projecting unit to be displayed on a display unit.

13. A method of controlling an image processing apparatus, the method comprising:

obtaining, from a three-dimensional image, information that represents a region of interest;

changing a projection direction of the three-dimensional image;

determining a parameter such that a thickness, in which the region of interest is included in the changed projection direction, represents a range sandwiched by two planes, in contact with the region of interest, orthogonal to the changed projection direction; and

generating a projection image by applying projection processing to the three-dimensional image using the determined parameter.

14. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method comprising:

obtaining, from a three-dimensional image, information that represents a region of interest;

changing a projection direction of the three-dimensional image;

determining a parameter such that a thickness, in which the region of interest is included in the changed projection direction, represents a range sandwiched by two planes, in contact with the region of interest, orthogonal to the changed projection direction; and

generating a projection image by applying projection processing to the three-dimensional image using the determined parameter.

15. A method of controlling an image processing apparatus, the method comprising:

obtaining, from a three-dimensional image, information that represents a region of interest;

changing a projection direction of the three-dimensional image;

setting a reference plane that is a plane orthogonal to the changed projection direction;

determining a parameter such that a thickness represents a range obtained based on a distance in the changed projection direction from the reference plane to a furthest position of the region of interest; and

generating a projection image by applying projection processing to the three-dimensional image using the determined parameter.

16. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method comprising:

obtaining, from a three-dimensional image, information that represents a region of interest;

changing a projection direction of the three-dimensional image;

setting a reference plane that is a plane orthogonal to the changed projection direction;

determining a parameter such that a thickness represents a range obtained based on a distance in the changed projection direction from the reference plane to a furthest position of the region of interest; and

generating a projection image by applying projection processing to the three-dimensional image using the determined parameter.