Cedar ConnorandClaude
cf9cab6102
- Implement multiple interpolation methods: nearest, bilinear, bicubic, lanczos - Add interpolation parameter to all three node types with dropdown selection - Use scipy map_coordinates with spline interpolation for rotation transforms - Use OpenCV LANCZOS4 for resize operations during cropping - Set Lanczos as default for highest quality filtering - Add proper longitude wrapping mode for equirectangular projection - Improve image quality significantly during transformations 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
209 lines
8.6 KiB
Python
209 lines
8.6 KiB
Python
import numpy as np
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import torch
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import cv2
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from typing import Tuple, Optional
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from scipy.spatial.transform import Rotation
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from scipy.ndimage import map_coordinates
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class EquirectangularProcessor:
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def __init__(self):
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pass
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@staticmethod
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def equirectangular_to_spherical(x: np.ndarray, y: np.ndarray, width: int, height: int) -> Tuple[np.ndarray, np.ndarray]:
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"""Convert equirectangular coordinates to spherical coordinates (lat, lon)"""
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lon = (x / width) * 2 * np.pi - np.pi # -π to π
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lat = np.pi/2 - (y / height) * np.pi # π/2 to -π/2
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return lat, lon
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@staticmethod
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def spherical_to_cartesian(lat: np.ndarray, lon: np.ndarray) -> Tuple[np.ndarray, np.ndarray, np.ndarray]:
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"""Convert spherical coordinates to 3D cartesian coordinates"""
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x = np.cos(lat) * np.cos(lon)
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y = np.cos(lat) * np.sin(lon)
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z = np.sin(lat)
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return x, y, z
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@staticmethod
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def cartesian_to_spherical(x: np.ndarray, y: np.ndarray, z: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
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"""Convert 3D cartesian coordinates to spherical coordinates"""
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lat = np.arcsin(np.clip(z, -1, 1))
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lon = np.arctan2(y, x)
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return lat, lon
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@staticmethod
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def spherical_to_equirectangular(lat: np.ndarray, lon: np.ndarray, width: int, height: int) -> Tuple[np.ndarray, np.ndarray]:
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"""Convert spherical coordinates to equirectangular coordinates"""
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# Normalize longitude to [0, 2π] then to [0, width]
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lon_norm = (lon + np.pi) / (2 * np.pi)
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x = lon_norm * width
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# Convert latitude from [π/2, -π/2] to [0, height]
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lat_norm = (np.pi/2 - lat) / np.pi
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y = lat_norm * height
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return x, y
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@staticmethod
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def create_rotation_matrix(yaw: float, pitch: float, roll: float) -> np.ndarray:
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"""Create 3D rotation matrix from yaw, pitch, roll angles in degrees"""
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yaw_rad = np.radians(yaw)
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pitch_rad = np.radians(pitch)
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roll_rad = np.radians(roll)
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# Using scipy for robust rotation matrix creation
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r = Rotation.from_euler('zyx', [yaw_rad, pitch_rad, roll_rad])
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return r.as_matrix()
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@staticmethod
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def apply_rotation(x: np.ndarray, y: np.ndarray, z: np.ndarray, rotation_matrix: np.ndarray) -> Tuple[np.ndarray, np.ndarray, np.ndarray]:
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"""Apply rotation matrix to 3D points"""
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points = np.stack([x, y, z], axis=-1)
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original_shape = points.shape[:-1]
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points_flat = points.reshape(-1, 3)
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rotated_points = points_flat @ rotation_matrix.T
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rotated_points = rotated_points.reshape(*original_shape, 3)
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return rotated_points[..., 0], rotated_points[..., 1], rotated_points[..., 2]
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@staticmethod
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def interpolate_image(image: np.ndarray, x: np.ndarray, y: np.ndarray, method: str = 'lanczos') -> np.ndarray:
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"""Perform high-quality interpolation on image at given coordinates"""
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height, width = image.shape[:2]
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# Handle different interpolation methods
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if method == 'nearest':
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order = 0
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elif method == 'bilinear':
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order = 1
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elif method == 'bicubic':
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order = 3
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elif method == 'lanczos':
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# Use scipy's map_coordinates with spline interpolation for high quality
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order = 3
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else:
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order = 3 # Default to bicubic
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# Clamp coordinates to valid range
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x = np.clip(x, 0, width - 1)
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y = np.clip(y, 0, height - 1)
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if len(image.shape) == 3: # Color image
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# Process each channel separately
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interpolated = np.zeros_like(image)
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for c in range(image.shape[2]):
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interpolated[..., c] = map_coordinates(
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image[..., c],
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[y, x],
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order=order,
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mode='wrap', # Wrap for equirectangular longitude wrapping
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prefilter=True
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)
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else: # Grayscale image
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interpolated = map_coordinates(
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image,
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[y, x],
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order=order,
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mode='wrap',
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prefilter=True
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)
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return interpolated
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@staticmethod
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def bilinear_interpolate(image: np.ndarray, x: np.ndarray, y: np.ndarray) -> np.ndarray:
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"""Legacy bilinear interpolation method - kept for compatibility"""
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return EquirectangularProcessor.interpolate_image(image, x, y, method='bilinear')
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@classmethod
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def rotate_equirectangular(cls, image: np.ndarray, yaw: float = 0, pitch: float = 0, roll: float = 0, horizon_offset: float = 0, interpolation: str = 'lanczos') -> np.ndarray:
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"""Rotate an equirectangular image with optional horizon adjustment"""
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height, width = image.shape[:2]
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# Create coordinate grids
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x_coords, y_coords = np.meshgrid(np.arange(width), np.arange(height))
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# Convert to spherical coordinates
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lat, lon = cls.equirectangular_to_spherical(x_coords, y_coords, width, height)
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# Apply horizon offset
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lat += np.radians(horizon_offset)
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lat = np.clip(lat, -np.pi/2, np.pi/2) # Clamp to valid latitude range
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# Convert to 3D cartesian
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x_3d, y_3d, z_3d = cls.spherical_to_cartesian(lat, lon)
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# Create and apply rotation matrix
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rotation_matrix = cls.create_rotation_matrix(yaw, pitch, roll)
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x_rot, y_rot, z_rot = cls.apply_rotation(x_3d, y_3d, z_3d, rotation_matrix)
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# Convert back to spherical
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lat_rot, lon_rot = cls.cartesian_to_spherical(x_rot, y_rot, z_rot)
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# Convert back to equirectangular coordinates
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x_new, y_new = cls.spherical_to_equirectangular(lat_rot, lon_rot, width, height)
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# Handle longitude wrapping
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x_new = np.mod(x_new, width)
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# Interpolate to get final image with specified method
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rotated_image = cls.interpolate_image(image, x_new, y_new, method=interpolation)
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return rotated_image
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@staticmethod
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def crop_to_180(image: np.ndarray, output_width: Optional[int] = None, output_height: Optional[int] = None, interpolation: str = 'lanczos') -> np.ndarray:
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"""Crop equirectangular image to 180 degree field of view"""
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height, width = image.shape[:2]
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# Calculate crop boundaries (center 180 degrees out of 360)
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start_x = width // 4 # Start at 90 degrees
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end_x = start_x + width // 2 # End at 270 degrees (180 degree span)
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# Crop the image
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cropped = image[:, start_x:end_x]
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# Resize if output dimensions specified with high-quality interpolation
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if output_width is not None and output_height is not None:
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# Map interpolation methods to OpenCV constants
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if interpolation == 'nearest':
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cv_interp = cv2.INTER_NEAREST
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elif interpolation == 'bilinear':
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cv_interp = cv2.INTER_LINEAR
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elif interpolation == 'bicubic':
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cv_interp = cv2.INTER_CUBIC
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elif interpolation == 'lanczos':
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cv_interp = cv2.INTER_LANCZOS4
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else:
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cv_interp = cv2.INTER_LANCZOS4 # Default to highest quality
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cropped = cv2.resize(cropped, (output_width, output_height), interpolation=cv_interp)
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return cropped
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@classmethod
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def process_equirectangular(cls,
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image: np.ndarray,
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yaw: float = 0,
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pitch: float = 0,
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roll: float = 0,
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horizon_offset: float = 0,
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crop_to_180: bool = False,
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output_width: Optional[int] = None,
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output_height: Optional[int] = None,
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interpolation: str = 'lanczos') -> np.ndarray:
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"""Main processing function that combines all operations"""
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# Apply rotation and horizon adjustment
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if yaw != 0 or pitch != 0 or roll != 0 or horizon_offset != 0:
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processed_image = cls.rotate_equirectangular(image, yaw, pitch, roll, horizon_offset, interpolation)
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else:
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processed_image = image.copy()
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# Apply 180-degree cropping if requested
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if crop_to_180:
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processed_image = cls.crop_to_180(processed_image, output_width, output_height, interpolation)
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return processed_image |