This is a Python library that enables you to use video cameras from Python on Windows. It is based on DirectShow. In particular, it allows to:
- Capture photos from a video camera
- View installed cameras on a system
- Set the camera options
- Save a vide captured from a camera
The library is available on PyPI: https://pypi.org/project/pygrabber/0.1/
# This code lists the cameras connected to your PC:
from pygrabber.dshow_graph import FilterGraph
graph = FilterGraph()
print(graph.get_input_devices())# Captures a frame from the first camera found on your computer every second and saves it to a file
import cv2
from datetime import datetime
from threading import Event, Thread
from pygrabber.dshow_graph import FilterGraph
from os import path
PAUSE_BETWEEN_CAPTURE = 1 # 1 sec.
OUTPUT_FOLDER = r"C:\test\\"
CAMERA_INDEX = 0 # Using first camera found
global start_time
def capture_photos_loop(event_):
global start_time
start_time = datetime.now()
while not event_.isSet():
graph.grab_frame()
event_.wait(PAUSE_BETWEEN_CAPTURE)
def show_image(image):
global start_time
capture_time = datetime.now() - start_time
image_file_name = path.join(OUTPUT_FOLDER, str(capture_time.seconds * 1000 + int(capture_time.microseconds / 1000)) + ".jpg")
cv2.imwrite(image_file_name, image)
print(f"Image {image_file_name} written")
if __name__ == "__main__":
event = Event()
capture_thread = Thread(target=capture_photos_loop, args=(event, ))
graph = FilterGraph()
devices = graph.get_input_devices()
print(f"Connecting to device {devices[CAMERA_INDEX]}")
graph.add_video_input_device(CAMERA_INDEX)
graph.add_sample_grabber(lambda image: show_image(image))
graph.add_null_render()
graph.prepare_preview_graph()
graph.run()
capture_thread.start()
input(f"Capturing images every {PAUSE_BETWEEN_CAPTURE}s, press ENTER to terminate.")
event.set()
capture_thread.join()
print("Done")# This code shows a screen with the live image from the first camera in your PC.
# We add to the graph two filters: one is a source filter corresponding to the first camera connected to your PC,
# the second is the default render, that shows the images from the camera in a window on the screen.
# Then we call prepare, that connects the two filters together, and run, to execute the graph.
# Finally, we need a method to pause the program while watching the camera video.
# I use the Tkinter mainloop function which fetches and handles Windows events, so the application does't seem frozen.
from pygrabber.dshow_graph import FilterGraph
from tkinter import Tk
graph = FilterGraph()
graph.add_video_input_device(0)
graph.add_default_render()
graph.prepare_preview_graph()
graph.run()
root = Tk()
root.withdraw() # hide Tkinter main window
root.mainloop()See also the other examples on the "examples" folder and the article https://www.codeproject.com/Articles/1274094/%2FArticles%2F1274094%2FCapturing-images-from-camera-using-Python-and-Dire.
The file run_gui.py will run a tool with a GUI that enables you to use a camera connected to your system, capture still frames or videos, do basic image porcessing.