Skip to main content

​
Overview

The CameraManager class provides a simple interface for capturing images from a USB camera using OpenCV. It handles camera initialization, frame buffering, and image saving. Source: arm_system/perception/vision/camera/main.py:5

​
Class Definition

​
CameraManager

class CameraManager:
    def __init__(self, camera_index: int = 0, width: int = 1280, height: int = 720)
Initializes camera with specified resolution.
​
camera_index
int
default:"0"
Camera device index (0 for default camera)
​
width
int
default:"1280"
Camera frame width in pixels
​
height
int
default:"720"
Camera frame height in pixels

​
Attributes

​
cap
cv2.VideoCapture
OpenCV video capture object

​
Methods

​
capture_image

def capture_image(self) -> str
Captures a single image from the camera and saves it to disk. Process:
  1. Grabs 5 frames to flush camera buffer
  2. Reads fresh frame
  3. Generates timestamped filename
  4. Creates output directory if needed
  5. Saves image as PNG
​
filename
str
Full path to saved image file, or None if capture failed
Output Directory: {script_directory}/objects_images/ Filename Format: YYYYMMDD-HHMMSS.png Source: arm_system/perception/vision/camera/main.py:11

​
Example

from arm_system.perception.vision.camera.main import CameraManager

# Initialize camera
camera = CameraManager(camera_index=0, width=1280, height=720)

# Capture image
image_path = camera.capture_image()

if image_path:
    print(f"Image saved to: {image_path}")
else:
    print("Failed to capture image")

​
Resource Management

The camera is automatically released when the CameraManager object is destroyed: 
def __del__(self):
    self.cap.release()
Source: arm_system/perception/vision/camera/main.py:28

​
Integration

The CameraManager is used by the CommunicationManager during scan operations: 
# In CommunicationManager.__init__
self.camera = CameraManager(camera_index=camera_index)

# In CommunicationManager._handle_object_detection
img_path = self.camera.capture_image()

​
Configuration

​
Supported Camera Indices

  • 0 - Default USB camera
  • 1, 2, etc. - Additional cameras (if connected)

​
Resolution Options

Common resolutions:
  • 1280x720 (720p HD) - Default
  • 1920x1080 (1080p Full HD)
  • 640x480 (VGA)

​
Error Handling

The capture_image() method returns None if:
  • Camera is not accessible
  • Frame read fails
  • No frame data available

​
Example Usage with Error Handling

from arm_system.perception.vision.camera.main import CameraManager
import time

camera = CameraManager()

# Capture multiple images with delay
for i in range(5):
    image_path = camera.capture_image()
    if image_path:
        print(f"Captured: {image_path}")
    else:
        print(f"Failed to capture image {i+1}")
    time.sleep(1)

Build docs developers (and LLMs) love

Get started for freeTalk to us