| 摘要 |
<p>In digital image processing according to the invention, a weight function F where the distance between pixels is a variable and a weight function H where the difference between the pixel values of neighboring pixels is a variable are set in filtering that uses a bilateral filter (step S4). Here, the PET image to be processed is not used; instead, a CT image is used as another digital image to set the weight function H, which gives a weight dependent on the edge intensity (the difference between the pixel values of the pixel of interest and an adjacent pixel) of the CT image. The CT image is also used in this manner as another digital image to determine filter coefficients (step S6). The determined filter coefficients are used in filtering of the PET image, which is the digital image to be processed (step S7). Therefore, filtering can be performed without being affected by the noise level of the PET image to be processed. As a result, spatial resolution is maintained while noise is reduced.</p> |
