Coverage for src/evutils/repr/_voxel.py: 100%

1 

2"""Module for generating voxel grid representations from events.""" 

3 

4from ._histogram import histogram 

5from ..chunking import window_delta_t 

6 

7 

8import numpy as np 

9 

10 

11from typing import Any 

12def voxel_histogram(events: np.ndarray, width: int = 1280, height: int = 720, n_bins: int = 10, dt: int = 10_000, dtype: Any = np.uint8) -> np.ndarray: 

13 """Generate a voxel grid from the events. 

14 

15 Parameters 

16 ---------- 

17 events : np.ndarray 

18 Array of events in the :class:`~evutils.types.Events` format. 

19 width : int, optional 

20 Width of the voxel grid, by default 1280. 

21 height : int, optional 

22 Height of the voxel grid, by default 720. 

23 n_bins : int, optional 

24 Number of depth bins (time slices) in the voxel grid, by default 10. 

25 dt : int, optional 

26 Time delta in microseconds for events buffer by default 10_000 (10 ms). 

27 dtype : np.dtype, optional 

28 Data type of the output voxel grid, by default np.uint8. 

29 

30 Returns 

31 ------- 

32 np.ndarray 

33 A numpy array with the voxel grid (n_bins, height, width, 3). 

34 

35 Examples 

36 -------- 

37 >>> import numpy as np 

38 >>> from evutils.repr import voxel_histogram 

39 >>> events = np.array([(10, 20, 100, 1), (15, 25, 200, 0), (20, 30, 10000, 1)], 

40 ... dtype=[('x', '<u2'), ('y', '<u2'), ('t', '<i8'), ('p', 'i1')]) 

41 >>> grid = voxel_histogram(events, width=100, height=100, n_bins=10, dt=10000) 

42 >>> grid.shape 

43 (10, 100, 100, 3) 

44 """ 

45 buffer = np.zeros((n_bins, height, width, 3), dtype=dtype) 

46 

47 

48 if len(events) <= 2: 

49 return buffer 

50 

51 assert events[-1]['t'] - events[0]['t'] <= dt # Ensure that the events are within the specified time delta 

52 

53 bin_dt = dt // n_bins # Time per bin in microseconds 

54 

55 for i, e in enumerate(window_delta_t(events, delta_t=bin_dt)): 

56 if i >= n_bins: 

57 break 

58 hist = histogram(e, width=width, height=height, fill=False, dtype=dtype) 

59 

60 # Only keep the r and b channels 

61 buffer[i] = hist 

62 

63 

64 

65 return buffer