262 lines
9.9 KiB
Python
262 lines
9.9 KiB
Python
from typing import *
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from functools import partial
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import math
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import cv2
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import numpy as np
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from scipy.signal import fftconvolve
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import numpy as np
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import utils3d
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from .tools import timeit
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def weighted_mean_numpy(x: np.ndarray, w: np.ndarray = None, axis: Union[int, Tuple[int,...]] = None, keepdims: bool = False, eps: float = 1e-7) -> np.ndarray:
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if w is None:
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return np.mean(x, axis=axis)
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else:
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w = w.astype(x.dtype)
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return (x * w).mean(axis=axis) / np.clip(w.mean(axis=axis), eps, None)
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def harmonic_mean_numpy(x: np.ndarray, w: np.ndarray = None, axis: Union[int, Tuple[int,...]] = None, keepdims: bool = False, eps: float = 1e-7) -> np.ndarray:
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if w is None:
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return 1 / (1 / np.clip(x, eps, None)).mean(axis=axis)
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else:
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w = w.astype(x.dtype)
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return 1 / (weighted_mean_numpy(1 / (x + eps), w, axis=axis, keepdims=keepdims, eps=eps) + eps)
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def normalized_view_plane_uv_numpy(width: int, height: int, aspect_ratio: float = None, dtype: np.dtype = np.float32) -> np.ndarray:
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"UV with left-top corner as (-width / diagonal, -height / diagonal) and right-bottom corner as (width / diagonal, height / diagonal)"
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if aspect_ratio is None:
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aspect_ratio = width / height
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span_x = aspect_ratio / (1 + aspect_ratio ** 2) ** 0.5
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span_y = 1 / (1 + aspect_ratio ** 2) ** 0.5
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u = np.linspace(-span_x * (width - 1) / width, span_x * (width - 1) / width, width, dtype=dtype)
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v = np.linspace(-span_y * (height - 1) / height, span_y * (height - 1) / height, height, dtype=dtype)
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u, v = np.meshgrid(u, v, indexing='xy')
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uv = np.stack([u, v], axis=-1)
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return uv
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def focal_to_fov_numpy(focal: np.ndarray):
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return 2 * np.arctan(0.5 / focal)
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def fov_to_focal_numpy(fov: np.ndarray):
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return 0.5 / np.tan(fov / 2)
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def intrinsics_to_fov_numpy(intrinsics: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
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fov_x = focal_to_fov_numpy(intrinsics[..., 0, 0])
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fov_y = focal_to_fov_numpy(intrinsics[..., 1, 1])
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return fov_x, fov_y
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def point_map_to_depth_legacy_numpy(points: np.ndarray):
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height, width = points.shape[-3:-1]
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diagonal = (height ** 2 + width ** 2) ** 0.5
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uv = normalized_view_plane_uv_numpy(width, height, dtype=points.dtype) # (H, W, 2)
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_, uv = np.broadcast_arrays(points[..., :2], uv)
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# Solve least squares problem
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b = (uv * points[..., 2:]).reshape(*points.shape[:-3], -1) # (..., H * W * 2)
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A = np.stack([points[..., :2], -uv], axis=-1).reshape(*points.shape[:-3], -1, 2) # (..., H * W * 2, 2)
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M = A.swapaxes(-2, -1) @ A
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solution = (np.linalg.inv(M + 1e-6 * np.eye(2)) @ (A.swapaxes(-2, -1) @ b[..., None])).squeeze(-1)
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focal, shift = solution
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depth = points[..., 2] + shift[..., None, None]
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fov_x = np.arctan(width / diagonal / focal) * 2
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fov_y = np.arctan(height / diagonal / focal) * 2
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return depth, fov_x, fov_y, shift
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def solve_optimal_focal_shift(uv: np.ndarray, xyz: np.ndarray):
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"Solve `min |focal * xy / (z + shift) - uv|` with respect to shift and focal"
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from scipy.optimize import least_squares
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uv, xy, z = uv.reshape(-1, 2), xyz[..., :2].reshape(-1, 2), xyz[..., 2].reshape(-1)
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def fn(uv: np.ndarray, xy: np.ndarray, z: np.ndarray, shift: np.ndarray):
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xy_proj = xy / (z + shift)[: , None]
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f = (xy_proj * uv).sum() / np.square(xy_proj).sum()
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err = (f * xy_proj - uv).ravel()
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return err
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solution = least_squares(partial(fn, uv, xy, z), x0=0, ftol=1e-3, method='lm')
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optim_shift = solution['x'].squeeze().astype(np.float32)
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xy_proj = xy / (z + optim_shift)[: , None]
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optim_focal = (xy_proj * uv).sum() / np.square(xy_proj).sum()
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return optim_shift, optim_focal
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def solve_optimal_shift(uv: np.ndarray, xyz: np.ndarray, focal: float):
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"Solve `min |focal * xy / (z + shift) - uv|` with respect to shift"
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from scipy.optimize import least_squares
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uv, xy, z = uv.reshape(-1, 2), xyz[..., :2].reshape(-1, 2), xyz[..., 2].reshape(-1)
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def fn(uv: np.ndarray, xy: np.ndarray, z: np.ndarray, shift: np.ndarray):
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xy_proj = xy / (z + shift)[: , None]
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err = (focal * xy_proj - uv).ravel()
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return err
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solution = least_squares(partial(fn, uv, xy, z), x0=0, ftol=1e-3, method='lm')
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optim_shift = solution['x'].squeeze().astype(np.float32)
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return optim_shift
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def recover_focal_shift_numpy(points: np.ndarray, mask: np.ndarray = None, focal: float = None, downsample_size: Tuple[int, int] = (64, 64)):
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import cv2
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assert points.shape[-1] == 3, "Points should (H, W, 3)"
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height, width = points.shape[-3], points.shape[-2]
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diagonal = (height ** 2 + width ** 2) ** 0.5
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uv = normalized_view_plane_uv_numpy(width=width, height=height)
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if mask is None:
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points_lr = cv2.resize(points, downsample_size, interpolation=cv2.INTER_LINEAR).reshape(-1, 3)
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uv_lr = cv2.resize(uv, downsample_size, interpolation=cv2.INTER_LINEAR).reshape(-1, 2)
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else:
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points_lr, uv_lr, mask_lr = utils3d.np.masked_nearest_resize(points, uv, mask=mask, size=downsample_size)
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if points_lr.size < 2:
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return 1., 0.
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if focal is None:
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shift,focal = solve_optimal_focal_shift(uv_lr, points_lr)
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else:
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shift = solve_optimal_shift(uv_lr, points_lr, focal)
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return focal, shift
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def norm3d(x: np.ndarray) -> np.ndarray:
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"Faster `np.linalg.norm(x, axis=-1)` for 3D vectors"
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return np.sqrt(np.square(x[..., 0]) + np.square(x[..., 1]) + np.square(x[..., 2]))
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def depth_occlusion_edge_numpy(depth: np.ndarray, mask: np.ndarray, thickness: int = 1, tol: float = 0.1):
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disp = np.where(mask, 1 / depth, 0)
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disp_pad = np.pad(disp, (thickness, thickness), constant_values=0)
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mask_pad = np.pad(mask, (thickness, thickness), constant_values=False)
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kernel_size = 2 * thickness + 1
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disp_window = utils3d.np.sliding_window(disp_pad, (kernel_size, kernel_size), 1, axis=(-2, -1)) # [..., H, W, kernel_size ** 2]
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mask_window = utils3d.np.sliding_window(mask_pad, (kernel_size, kernel_size), 1, axis=(-2, -1)) # [..., H, W, kernel_size ** 2]
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disp_mean = weighted_mean_numpy(disp_window, mask_window, axis=(-2, -1))
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fg_edge_mask = mask & (disp > (1 + tol) * disp_mean)
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bg_edge_mask = mask & (disp_mean > (1 + tol) * disp)
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edge_mask = (cv2.dilate(fg_edge_mask.astype(np.uint8), np.ones((3, 3), dtype=np.uint8), iterations=thickness) > 0) \
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& (cv2.dilate(bg_edge_mask.astype(np.uint8), np.ones((3, 3), dtype=np.uint8), iterations=thickness) > 0)
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return edge_mask
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def disk_kernel(radius: int) -> np.ndarray:
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"""
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Generate disk kernel with given radius.
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Args:
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radius (int): Radius of the disk (in pixels).
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Returns:
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np.ndarray: (2*radius+1, 2*radius+1) normalized convolution kernel.
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"""
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# Create coordinate grid centered at (0,0)
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L = np.arange(-radius, radius + 1)
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X, Y = np.meshgrid(L, L)
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# Generate disk: region inside circle with radius R is 1
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kernel = ((X**2 + Y**2) <= radius**2).astype(np.float32)
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# Normalize the kernel
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kernel /= np.sum(kernel)
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return kernel
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def disk_blur(image: np.ndarray, radius: int) -> np.ndarray:
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"""
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Apply disk blur to an image using FFT convolution.
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Args:
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image (np.ndarray): Input image, can be grayscale or color.
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radius (int): Blur radius (in pixels).
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Returns:
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np.ndarray: Blurred image.
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"""
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if radius == 0:
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return image
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kernel = disk_kernel(radius)
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if image.ndim == 2:
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blurred = fftconvolve(image, kernel, mode='same')
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elif image.ndim == 3:
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channels = []
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for i in range(image.shape[2]):
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blurred_channel = fftconvolve(image[..., i], kernel, mode='same')
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channels.append(blurred_channel)
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blurred = np.stack(channels, axis=-1)
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else:
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raise ValueError("Image must be 2D or 3D.")
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return blurred
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def depth_of_field(
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img: np.ndarray,
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disp: np.ndarray,
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focus_disp : float,
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max_blur_radius : int = 10,
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) -> np.ndarray:
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"""
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Apply depth of field effect to an image.
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Args:
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img (numpy.ndarray): (H, W, 3) input image.
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depth (numpy.ndarray): (H, W) depth map of the scene.
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focus_depth (float): Focus depth of the lens.
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strength (float): Strength of the depth of field effect.
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max_blur_radius (int): Maximum blur radius (in pixels).
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Returns:
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numpy.ndarray: (H, W, 3) output image with depth of field effect applied.
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"""
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# Precalculate dialated depth map for each blur radius
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max_disp = np.max(disp)
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disp = disp / max_disp
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focus_disp = focus_disp / max_disp
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dilated_disp = []
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for radius in range(max_blur_radius + 1):
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dilated_disp.append(cv2.dilate(disp, cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (2*radius+1, 2*radius+1)), iterations=1))
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# Determine the blur radius for each pixel based on the depth map
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blur_radii = np.clip(abs(disp - focus_disp) * max_blur_radius, 0, max_blur_radius).astype(np.int32)
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for radius in range(max_blur_radius + 1):
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dialted_blur_radii = np.clip(abs(dilated_disp[radius] - focus_disp) * max_blur_radius, 0, max_blur_radius).astype(np.int32)
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mask = (dialted_blur_radii >= radius) & (dialted_blur_radii >= blur_radii) & (dilated_disp[radius] > disp)
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blur_radii[mask] = dialted_blur_radii[mask]
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blur_radii = np.clip(blur_radii, 0, max_blur_radius)
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blur_radii = cv2.blur(blur_radii, (5, 5))
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# Precalculate the blured image for each blur radius
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unique_radii = np.unique(blur_radii)
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precomputed = {}
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for radius in range(max_blur_radius + 1):
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if radius not in unique_radii:
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continue
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precomputed[radius] = disk_blur(img, radius)
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# Composit the blured image for each pixel
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output = np.zeros_like(img)
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for r in unique_radii:
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mask = blur_radii == r
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output[mask] = precomputed[r][mask]
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return output
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