Radiographic imaging device and radiographic imaging method using interpolation from hexagonal to square pixels
A radiographic imaging device includes a radiation detection element including plural same sized hexagonal shaped pixels that detect radiation and are arrayed in a honeycomb pattern, and a pixel density conversion section that performs interpolation processing such that first image data obtained from the radiation detection element is converted into second image data representing an image in which plural pixels are arrayed in a square grid pattern, wherein when d 1 max denotes the length of the longest diagonal of the hexagonal shaped pixels, S 1 denotes the surface area of the hexagonal shaped pixels, and d 2 max denotes the length of the diagonals of the square grid of the second image data, d 1 max is equal to or greater than d 2 max, and d 2 max is equal to or greater than the value of the square root of S 1.
1. A radiographic imaging device comprising:
a radiation detection element including a plurality of same sized hexagonal shaped pixels that detect radiation and are arrayed in a honeycomb pattern; and
a pixel density conversion section that performs interpolation processing such that first image data obtained from the radiation detection element is converted into second image data representing an image in which plural pixels are arrayed in a square grid pattern,
wherein, in the radiographic imaging device, the following expression is satisfied,
√ S 1 ≤d 2max≤ d 1max<√(2× S 1)
wherein d 1 max denotes the length of the longest diagonal of the hexagonal shaped pixels, S 1 denotes the surface area of the hexagonal shaped pixels, and d 2 max denotes the length of the diagonals of the square grid of the second image data.
2. The radiographic imaging device of claim 1 , wherein the direction of one axis of the diagonals of the hexagonal shaped pixels coincides with the direction of one axis of the square grid, and the hexagonal shape is symmetrical with respect to the one axis of the diagonals.
3. The radiographic imaging device of claim 1 , wherein the hexagonal shaped pixels are formed to have a regular hexagonal shape.
4. The radiographic imaging device of claim 1 , wherein the pixel density conversion section performs interpolation processing first in the direction out of a horizontal direction and a vertical direction in the first image data that has a shorter pixel array pitch, and then performs the interpolation processing in the other direction.
5. The radiographic imaging device of claim 1 , further comprising:
a radiation source that irradiates radiation; and
an image output device that outputs an image on the basis of the second image data.
6. A radiographic imaging method comprising:
detecting first image data using a radiation detection element that includes a plurality of same sized hexagonal shaped pixels that detect radiation and are arrayed in a honeycomb pattern; and
performing interpolation processing such that the first image data is converted into second image data representing an image of a plurality of pixels arrayed in a square grid pattern,
wherein, in the radiographic imaging method, the following expression is satisfied,
√ S 1 ≤d 2max≤ d 1max <√(2× S 1)
wherein d 1 max denotes the length of the longest diagonal of the hexagonal shaped pixels, S 1 denotes the surface area of the hexagonal shaped pixels, and d 2 max denotes the length of the diagonals of the square grid of the second image data.
7. The radiographic imaging method of claim 6 , wherein the direction of one axis of the diagonals of the hexagonal shaped pixels coincides with the direction of one axis of the square grid, and the hexagonal shape is symmetrical with respect to the one axis of the diagonals.
8. The radiographic imaging method of claim 6 , wherein the hexagonal shaped pixels have a regular hexagonal shape.
9. The radiographic imaging method of claim 6 , wherein the interpolation processing is first performed in the direction out of a horizontal direction and a vertical direction in the first image data that has a shorter pixel array pitch, and then performs the interpolation processing in the other direction.
10. The radiographic imaging method of claim 6 , further comprising outputting an image based on the second image data.
11. The radiographic imaging device of claim 1 , wherein the hexagonal shaped pixels have flattened hexagonal shape in which one diagonal of diagonals passing through a center is shorter than other two diagonals and lengths of the other two diagonals is equal,
wherein flattening ratio of the flattened hexagonal shape is equal to or more than 70% and is less than 100%, and
wherein, d 2 max≤d 1 max<√(2×S 1 ) is also satisfied.
12. The radiographic imaging method of claim 6 , wherein the hexagonal shaped pixels have flattened hexagonal shape in which one diagonal of diagonals passing through a center is shorter than other two diagonals and lengths of the other two diagonals is equal,
wherein flattening ratio of the flattened hexagonal shape is equal to or more than 70% and is less than 100%, and
wherein, d 2 max≤d 1 max<√(2×S 1 ) is also satisfied.