33 lines
1.1 KiB
Python
33 lines
1.1 KiB
Python
from typing import Sequence
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import numpy as np
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def get_anchor_grid(
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num_rows: int,
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num_cols: int,
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scale_factor: float,
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anchor_widths: Sequence[float],
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aspect_ratios: Sequence[float],
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) -> np.ndarray:
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anchor_grid = np.empty(
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[len(width), len(ratio), num_rows, num_cols, 4], dtype=int)
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for width_idx, width in enumerate(anchor_widths):
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for ratio_idx, ratio in enumerate(aspect_ratios):
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for row in range(num_rows):
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for col in range(num_cols):
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anchor_point = (
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col * scale_factor + scale_factor/2, row * scale_factor + scale_factor / 2)
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anchor_grid[width_idx, ratio_idx, row, col] = get_box(
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width, ratio, anchor_point)
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return anchor_grid
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def get_box(width: float, ratio: float, anchor_point: tuple[float, float]) -> np.ndarray:
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box = np.empty(4)
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box[0] = anchor_point[0] - (width / 2)
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box[1] = anchor_point[1] - (width * ratio / 2)
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box[2] = anchor_point[0] + (width / 2)
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box[3] = anchor_point[1] + (width * ratio / 2)
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return box
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