a6dHddlZddlmZddlmZmZdddddd Zd Zd Z dS) N)_supported_float_type) apply_kernelapply_kernel_nandF)radiuskernelnansafe num_threadsc tj|}t|j}||d}|d}|t ||j}||}tj|j}|dz}|t|} | |z } tj | |tj k<| |j} | d} tj ||ddtj ftj d}|rtnt} | | d| tj||j  dtj|jtj tj|jtj |tj|} | |jd} | S) a` Estimate background intensity by rolling/translating a kernel. This rolling ball algorithm estimates background intensity for a ndimage in case of uneven exposure. It is a generalization of the frequently used rolling ball algorithm [1]_. Parameters ---------- image : ndarray The image to be filtered. radius : int, optional Radius of a ball shaped kernel to be rolled/translated in the image. Used if ``kernel = None``. kernel : ndarray, optional The kernel to be rolled/translated in the image. It must have the same number of dimensions as ``image``. Kernel is filled with the intensity of the kernel at that position. nansafe: bool, optional If ``False`` (default) assumes that none of the values in ``image`` are ``np.nan``, and uses a faster implementation. num_threads: int, optional The maximum number of threads to use. If ``None`` use the OpenMP default value; typically equal to the maximum number of virtual cores. Note: This is an upper limit to the number of threads. The exact number is determined by the system's OpenMP library. Returns ------- background : ndarray The estimated background of the image. Notes ----- For the pixel that has its background intensity estimated (without loss of generality at ``center``) the rolling ball method centers ``kernel`` under it and raises the kernel until the surface touches the image umbra at some ``pos=(y,x)``. The background intensity is then estimated using the image intensity at that position (``image[pos]``) plus the difference of ``kernel[center] - kernel[pos]``. This algorithm assumes that dark pixels correspond to the background. If you have a bright background, invert the image before passing it to the function, e.g., using `utils.invert`. See the gallery example for details. This algorithm is sensitive to noise (in particular salt-and-pepper noise). If this is a problem in your image, you can apply mild gaussian smoothing before passing the image to this function. References ---------- .. [1] Sternberg, Stanley R. "Biomedical image processing." Computer 1 (1983): 22-34. :DOI:`10.1109/MC.1983.1654163` Examples -------- >>> import numpy as np >>> from skimage import data >>> from skimage.restoration import rolling_ball >>> image = data.coins() >>> background = rolling_ball(data.coins()) >>> filtered_image = image - background >>> import numpy as np >>> from skimage import data >>> from skimage.restoration import rolling_ball, ellipsoid_kernel >>> image = data.coins() >>> kernel = ellipsoid_kernel((101, 101), 75) >>> background = rolling_ball(data.coins(), kernel=kernel) >>> filtered_image = image - background F)copyNrrconstant)constant_valuesmode)dtype)npasarrayrrastype ball_kernelndimshapetupleInfreshapepadnewaxisrr zeros_likearrayintp) imager r r r float_typeimg kernel_shape kernel_centercenter_intensityintensity_differencefunc backgrounds @lib/python3.11/site-packages/skimage/restoration/rolling_ball.py rolling_ballr,sT Ju  E&u{33J ,,z, . .C  ~VUZ00 ]]: & &F:fl++L!Q&MeM223+f4-/V26)*/66syAA/77;; &mAAArzM2!#j : : :C ' 8  LD B e39---55b99 BG,,, "'***BG$$J""5;U";;J cltjtjdtj|g|zDddid}tj|dzd}tj|}tjtj|dz|z dd}tj|||k<|S) aCreate a ball kernel for restoration.rolling_ball. Parameters ---------- radius : int Radius of the ball. ndim : int Number of dimensions of the ball. ``ndim`` should match the dimensionality of the image the kernel will be applied to. Returns ------- kernel : ndarray The kernel containing the surface intensity of the top half of the ellipsoid. See Also -------- rolling_ball c@g|]}tj| |dzSrrarange.0xs r+ zball_kernel..s* E E EqbiAE"" E E Er-indexingijraxisrrN)rstackmeshgridceilsumsqrtclipr)r r kernel_coordssum_of_squaresdistance_from_centerr s r+rrxs,H E ERWV__,=,D E E E    MVMQ.R888N7>22 WRWVq[>91dCC D DF,.FF & () Mr-cxtj|}tj|dzdd}tjtjd|Dddid}dtj||z dzdz }|tjtj|d dz}tj||d k<|S) a/Create an ellipoid kernel for restoration.rolling_ball. Parameters ---------- shape : arraylike Length of the principal axis of the ellipsoid (excluding the intensity axis). The kernel needs to have the same dimensionality as the image it will be applied to. intensity : int Length of the intensity axis of the ellipsoid. Returns ------- kernel : ndarray The kernel containing the surface intensity of the top half of the ellipsoid. See Also -------- rolling_ball rrNc@g|]}tj| |dzSr0r1r3s r+r6z$ellipsoid_kernel..s* 6 6 6qbiAE"" 6 6 6r-r7r8rr9r)rrr@r;r<r>r?r)r intensity semi_axisrAintensity_scalingr s r+ellipsoid_kernelrIs. Ju  E At,,IH 6 6I 6 6 6    MBFMI$=!#C"MMMM ):At!D!DEE EF$&FF q ! Mr-) numpyr _shared.utilsr_rolling_ball_cyrrr,rrIr-r+rNs111111<<<<<<<<#&dDnnnnnb###L%%%%%r-