supervision/supervision/annotators/core.py

956 lines
33 KiB
Python

from math import sqrt
from typing import List, Optional, Tuple, Union
import cv2
import numpy as np
from supervision.annotators.base import BaseAnnotator
from supervision.annotators.utils import ColorLookup, Trace, resolve_color
from supervision.detection.core import Detections
from supervision.draw.color import Color, ColorPalette
from supervision.geometry.core import Position
class BoundingBoxAnnotator(BaseAnnotator):
"""
A class for drawing bounding boxes on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
thickness: int = 2,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
thickness (int): Thickness of the bounding box lines.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.thickness: int = thickness
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with bounding boxes based on the provided detections.
Args:
scene (np.ndarray): The image where bounding boxes will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> bounding_box_annotator = sv.BoundingBoxAnnotator()
>>> annotated_frame = bounding_box_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![bounding-box-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/bounding-box-annotator-example-purple.png)
"""
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
cv2.rectangle(
img=scene,
pt1=(x1, y1),
pt2=(x2, y2),
color=color.as_bgr(),
thickness=self.thickness,
)
return scene
class MaskAnnotator(BaseAnnotator):
"""
A class for drawing masks on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
opacity: float = 0.5,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
opacity (float): Opacity of the overlay mask. Must be between `0` and `1`.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.opacity = opacity
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with masks based on the provided detections.
Args:
scene (np.ndarray): The image where masks will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> mask_annotator = sv.MaskAnnotator()
>>> annotated_frame = mask_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![mask-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/mask-annotator-example-purple.png)
"""
if detections.mask is None:
return scene
for detection_idx in np.flip(np.argsort(detections.area)):
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
mask = detections.mask[detection_idx]
colored_mask = np.zeros_like(scene, dtype=np.uint8)
colored_mask[:] = color.as_bgr()
scene[mask] = cv2.addWeighted(
colored_mask, self.opacity, scene, 1 - self.opacity, 0
)[mask]
return scene
class BoxMaskAnnotator(BaseAnnotator):
"""
A class for drawing box masks on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
opacity: float = 0.5,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
opacity (float): Opacity of the overlay mask. Must be between `0` and `1`.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.color_lookup: ColorLookup = color_lookup
self.opacity = opacity
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with box masks based on the provided detections.
Args:
scene (np.ndarray): The image where bounding boxes will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> box_mask_annotator = sv.BoxMaskAnnotator()
>>> annotated_frame = box_mask_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![box-mask-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/box-mask-annotator-example-purple.png)
"""
mask_image = scene.copy()
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
cv2.rectangle(
img=scene,
pt1=(x1, y1),
pt2=(x2, y2),
color=color.as_bgr(),
thickness=-1,
)
scene = cv2.addWeighted(
scene, self.opacity, mask_image, 1 - self.opacity, gamma=0
)
return scene
class HaloAnnotator(BaseAnnotator):
"""
A class for drawing Halos on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
opacity: float = 0.8,
kernel_size: int = 40,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
opacity (float): Opacity of the overlay mask. Must be between `0` and `1`.
kernel_size (int): The size of the average pooling kernel used for creating
the halo.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.opacity = opacity
self.color_lookup: ColorLookup = color_lookup
self.kernel_size: int = kernel_size
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with halos based on the provided detections.
Args:
scene (np.ndarray): The image where masks will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> halo_annotator = sv.HaloAnnotator()
>>> annotated_frame = halo_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![halo-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/halo-annotator-example-purple.png)
"""
if detections.mask is None:
return scene
colored_mask = np.zeros_like(scene, dtype=np.uint8)
fmask = np.array([False] * scene.shape[0] * scene.shape[1]).reshape(
scene.shape[0], scene.shape[1]
)
for detection_idx in np.flip(np.argsort(detections.area)):
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
mask = detections.mask[detection_idx]
fmask = np.logical_or(fmask, mask)
color_bgr = color.as_bgr()
colored_mask[mask] = color_bgr
colored_mask = cv2.blur(colored_mask, (self.kernel_size, self.kernel_size))
colored_mask[fmask] = [0, 0, 0]
gray = cv2.cvtColor(colored_mask, cv2.COLOR_BGR2GRAY)
alpha = self.opacity * gray / gray.max()
alpha_mask = alpha[:, :, np.newaxis]
scene = np.uint8(scene * (1 - alpha_mask) + colored_mask * self.opacity)
return scene
class EllipseAnnotator(BaseAnnotator):
"""
A class for drawing ellipses on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
thickness: int = 2,
start_angle: int = -45,
end_angle: int = 235,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
thickness (int): Thickness of the ellipse lines.
start_angle (int): Starting angle of the ellipse.
end_angle (int): Ending angle of the ellipse.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.thickness: int = thickness
self.start_angle: int = start_angle
self.end_angle: int = end_angle
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with ellipses based on the provided detections.
Args:
scene (np.ndarray): The image where ellipses will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> ellipse_annotator = sv.EllipseAnnotator()
>>> annotated_frame = ellipse_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![ellipse-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/ellipse-annotator-example-purple.png)
"""
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
center = (int((x1 + x2) / 2), y2)
width = x2 - x1
cv2.ellipse(
scene,
center=center,
axes=(int(width), int(0.35 * width)),
angle=0.0,
startAngle=self.start_angle,
endAngle=self.end_angle,
color=color.as_bgr(),
thickness=self.thickness,
lineType=cv2.LINE_4,
)
return scene
class BoxCornerAnnotator(BaseAnnotator):
"""
A class for drawing box corners on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
thickness: int = 4,
corner_length: int = 15,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
thickness (int): Thickness of the corner lines.
corner_length (int): Length of each corner line.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.thickness: int = thickness
self.corner_length: int = corner_length
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with box corners based on the provided detections.
Args:
scene (np.ndarray): The image where box corners will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> corner_annotator = sv.BoxCornerAnnotator()
>>> annotated_frame = corner_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![box-corner-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/box-corner-annotator-example-purple.png)
"""
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
corners = [(x1, y1), (x2, y1), (x1, y2), (x2, y2)]
for x, y in corners:
x_end = x + self.corner_length if x == x1 else x - self.corner_length
cv2.line(
scene, (x, y), (x_end, y), color.as_bgr(), thickness=self.thickness
)
y_end = y + self.corner_length if y == y1 else y - self.corner_length
cv2.line(
scene, (x, y), (x, y_end), color.as_bgr(), thickness=self.thickness
)
return scene
class CircleAnnotator(BaseAnnotator):
"""
A class for drawing circle on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
thickness: int = 2,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating detections.
thickness (int): Thickness of the circle line.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.thickness: int = thickness
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with circles based on the provided detections.
Args:
scene (np.ndarray): The image where box corners will be drawn.
detections (Detections): Object detections to annotate.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> circle_annotator = sv.CircleAnnotator()
>>> annotated_frame = circle_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![circle-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/circle-annotator-example-purple.png)
"""
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
center = ((x1 + x2) // 2, (y1 + y2) // 2)
distance = sqrt((x1 - center[0]) ** 2 + (y1 - center[1]) ** 2)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
cv2.circle(
img=scene,
center=center,
radius=int(distance),
color=color.as_bgr(),
thickness=self.thickness,
)
return scene
class DotAnnotator(BaseAnnotator):
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
radius: int = 4,
position: Position = Position.CENTER,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
self.color: Union[Color, ColorPalette] = color
self.radius: int = radius
self.position: Position = position
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
xy = detections.get_anchor_coordinates(anchor=self.position)
for detection_idx in range(len(detections)):
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
center = (int(xy[detection_idx, 0]), int(xy[detection_idx, 1]))
cv2.circle(scene, center, self.radius, color.as_bgr(), -1)
return scene
class LabelAnnotator:
"""
A class for annotating labels on an image using provided detections.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
text_color: Color = Color.black(),
text_scale: float = 0.5,
text_thickness: int = 1,
text_padding: int = 10,
text_position: Position = Position.TOP_LEFT,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color or color palette to use for
annotating the text background.
text_color (Color): The color to use for the text.
text_scale (float): Font scale for the text.
text_thickness (int): Thickness of the text characters.
text_padding (int): Padding around the text within its background box.
text_position (Position): Position of the text relative to the detection.
Possible values are defined in the `Position` enum.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.text_color: Color = text_color
self.text_scale: float = text_scale
self.text_thickness: int = text_thickness
self.text_padding: int = text_padding
self.text_position: Position = text_position
self.color_lookup: ColorLookup = color_lookup
@staticmethod
def resolve_text_background_xyxy(
detection_xyxy: Tuple[int, int, int, int],
text_wh: Tuple[int, int],
text_padding: int,
position: Position,
) -> Tuple[int, int, int, int]:
padded_text_wh = (text_wh[0] + 2 * text_padding, text_wh[1] + 2 * text_padding)
x1, y1, x2, y2 = detection_xyxy
center_x = (x1 + x2) // 2
center_y = (y1 + y2) // 2
if position == Position.TOP_LEFT:
return x1, y1 - padded_text_wh[1], x1 + padded_text_wh[0], y1
elif position == Position.TOP_RIGHT:
return x2 - padded_text_wh[0], y1 - padded_text_wh[1], x2, y1
elif position == Position.TOP_CENTER:
return (
center_x - padded_text_wh[0] // 2,
y1 - padded_text_wh[1],
center_x + padded_text_wh[0] // 2,
y1,
)
elif position == Position.CENTER:
return (
center_x - padded_text_wh[0] // 2,
center_y - padded_text_wh[1] // 2,
center_x + padded_text_wh[0] // 2,
center_y + padded_text_wh[1] // 2,
)
elif position == Position.BOTTOM_LEFT:
return x1, y2, x1 + padded_text_wh[0], y2 + padded_text_wh[1]
elif position == Position.BOTTOM_RIGHT:
return x2 - padded_text_wh[0], y2, x2, y2 + padded_text_wh[1]
elif position == Position.BOTTOM_CENTER:
return (
center_x - padded_text_wh[0] // 2,
y2,
center_x + padded_text_wh[0] // 2,
y2 + padded_text_wh[1],
)
def annotate(
self,
scene: np.ndarray,
detections: Detections,
labels: List[str] = None,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Annotates the given scene with labels based on the provided detections.
Args:
scene (np.ndarray): The image where labels will be drawn.
detections (Detections): Object detections to annotate.
labels (List[str]): Optional. Custom labels for each detection.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> label_annotator = sv.LabelAnnotator(text_position=sv.Position.CENTER)
>>> annotated_frame = label_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![label-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/label-annotator-example-purple.png)
"""
font = cv2.FONT_HERSHEY_SIMPLEX
for detection_idx in range(len(detections)):
detection_xyxy = detections.xyxy[detection_idx].astype(int)
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
text = (
f"{detections.class_id[detection_idx]}"
if (labels is None or len(detections) != len(labels))
else labels[detection_idx]
)
text_wh = cv2.getTextSize(
text=text,
fontFace=font,
fontScale=self.text_scale,
thickness=self.text_thickness,
)[0]
text_background_xyxy = self.resolve_text_background_xyxy(
detection_xyxy=detection_xyxy,
text_wh=text_wh,
text_padding=self.text_padding,
position=self.text_position,
)
text_x = text_background_xyxy[0] + self.text_padding
text_y = text_background_xyxy[1] + self.text_padding + text_wh[1]
cv2.rectangle(
img=scene,
pt1=(text_background_xyxy[0], text_background_xyxy[1]),
pt2=(text_background_xyxy[2], text_background_xyxy[3]),
color=color.as_bgr(),
thickness=cv2.FILLED,
)
cv2.putText(
img=scene,
text=text,
org=(text_x, text_y),
fontFace=font,
fontScale=self.text_scale,
color=self.text_color.as_rgb(),
thickness=self.text_thickness,
lineType=cv2.LINE_AA,
)
return scene
class BlurAnnotator(BaseAnnotator):
"""
A class for blurring regions in an image using provided detections.
"""
def __init__(self, kernel_size: int = 15):
"""
Args:
kernel_size (int): The size of the average pooling kernel used for blurring.
"""
self.kernel_size: int = kernel_size
def annotate(
self,
scene: np.ndarray,
detections: Detections,
) -> np.ndarray:
"""
Annotates the given scene by blurring regions based on the provided detections.
Args:
scene (np.ndarray): The image where blurring will be applied.
detections (Detections): Object detections to annotate.
Returns:
np.ndarray: The annotated image.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> blur_annotator = sv.BlurAnnotator()
>>> annotated_frame = blur_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![blur-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/blur-annotator-example-purple.png)
"""
for detection_idx in range(len(detections)):
x1, y1, x2, y2 = detections.xyxy[detection_idx].astype(int)
roi = scene[y1:y2, x1:x2]
roi = cv2.blur(roi, (self.kernel_size, self.kernel_size))
scene[y1:y2, x1:x2] = roi
return scene
class TraceAnnotator:
"""
A class for drawing trace paths on an image based on detection coordinates.
!!! warning
This annotator utilizes the `tracker_id`. Read
[here](https://supervision.roboflow.com/trackers/) to learn how to plug
tracking into your inference pipeline.
"""
def __init__(
self,
color: Union[Color, ColorPalette] = ColorPalette.default(),
position: Optional[Position] = Position.CENTER,
trace_length: int = 30,
thickness: int = 2,
color_lookup: ColorLookup = ColorLookup.CLASS,
):
"""
Args:
color (Union[Color, ColorPalette]): The color to draw the trace, can be
a single color or a color palette.
position (Optional[Position]): The position of the trace.
Defaults to `CENTER`.
trace_length (int): The maximum length of the trace in terms of historical
points. Defaults to `30`.
thickness (int): The thickness of the trace lines. Defaults to `2`.
color_lookup (str): Strategy for mapping colors to annotations.
Options are `INDEX`, `CLASS`, `TRACE`.
"""
self.color: Union[Color, ColorPalette] = color
self.position = position
self.trace = Trace(max_size=trace_length)
self.thickness = thickness
self.color_lookup: ColorLookup = color_lookup
def annotate(
self,
scene: np.ndarray,
detections: Detections,
custom_color_lookup: Optional[np.ndarray] = None,
) -> np.ndarray:
"""
Draws trace paths on the frame based on the detection coordinates provided.
Args:
scene (np.ndarray): The image on which the traces will be drawn.
detections (Detections): The detections which include coordinates for
which the traces will be drawn.
custom_color_lookup (Optional[np.ndarray]): Custom color lookup array.
Allows to override the default color mapping strategy.
Returns:
np.ndarray: The image with the trace paths drawn on it.
Example:
```python
>>> import supervision as sv
>>> image = ...
>>> detections = sv.Detections(...)
>>> trace_annotator = sv.TraceAnnotator()
>>> annotated_frame = trace_annotator.annotate(
... scene=image.copy(),
... detections=detections
... )
```
![trace-annotator-example](https://media.roboflow.com/
supervision-annotator-examples/trace-annotator-example-purple.png)
"""
self.trace.put(detections)
for detection_idx in range(len(detections)):
tracker_id = int(detections.tracker_id[detection_idx])
color = resolve_color(
color=self.color,
detections=detections,
detection_idx=detection_idx,
color_lookup=self.color_lookup
if custom_color_lookup is None
else custom_color_lookup,
)
xy = self.trace.get(tracker_id=tracker_id)
if len(xy) > 1:
scene = cv2.polylines(
scene,
[xy.astype(np.int32)],
False,
color=color.as_bgr(),
thickness=self.thickness,
)
return scene