Drawing

powerboxes.draw_boxes(image, boxes, colors=None, thickness=2, filled=False, opacity=1.0)

Draw bounding boxes on an image.

Parameters:

Name	Type	Description	Default
image	NDArray[uint8]	3d array of shape (3, H, W) in CHW format, uint8	required
boxes	NDArray[float64]	2d array of boxes in xyxy format, float64	required
colors	NDArray[uint8]	optional 2d array of shape (N, 3) with RGB colors per box, uint8	None
thickness	int	line thickness in pixels (default 2)	2
filled	bool	whether to fill box interiors before drawing outlines	False
opacity	float	alpha blend strength in the range [0.0, 1.0]	1.0

Raises:

Type	Description
TypeError	if image or boxes are not numpy arrays

Returns:

Type	Description
NDArray[uint8]	np.ndarray: 3d array of shape (3, H, W) with boxes drawn

draw_boxes draws axis-aligned xyxy boxes on CHW uint8 images.

Axis-Aligned Example

import numpy as np
import powerboxes as pb

image = np.zeros((3, 100, 100), dtype=np.uint8)
boxes = np.array(
    [
        [10.0, 10.0, 50.0, 50.0],
        [20.0, 20.0, 80.0, 70.0],
    ]
)

outlined = pb.draw_boxes(image, boxes)
filled = pb.draw_boxes(image, boxes, filled=True, opacity=0.35)

Rotated Boxes

powerboxes.draw_rotated_boxes(image, boxes, colors=None, thickness=2, filled=False, opacity=1.0)

Draw rotated bounding boxes on an image.

Parameters:

Name	Type	Description	Default
image	NDArray[uint8]	3d array of shape (3, H, W) in CHW format, uint8	required
boxes	NDArray[float64]	2d array of boxes in cxcywha format, float64	required
colors	NDArray[uint8]	optional 2d array of shape (N, 3) with RGB colors per box, uint8	None
thickness	int	line thickness in pixels (default 2)	2
filled	bool	whether to fill box interiors before drawing outlines	False
opacity	float	alpha blend strength in the range [0.0, 1.0]	1.0

Raises:

Type	Description
TypeError	if image or boxes are not numpy arrays

Returns:

Type	Description
NDArray[uint8]	np.ndarray: 3d array of shape (3, H, W) with boxes drawn

draw_rotated_boxes draws cxcywha boxes using general line rasterization, so non-axis-aligned edges render correctly.

import numpy as np
import powerboxes as pb

image = np.zeros((3, 100, 100), dtype=np.uint8)
rotated_boxes = np.array(
    [
        [50.0, 50.0, 30.0, 20.0, 30.0],
        [60.0, 35.0, 20.0, 10.0, -20.0],
    ]
)

result = pb.draw_rotated_boxes(image, rotated_boxes, filled=True, opacity=0.4)

Notes

• Images use CHW layout: (3, H, W).
• colors must have shape (N, 3) when provided.
• opacity must be in the closed interval [0.0, 1.0].