camera.py

# MIT License
# Copyright (c) 2019 JetsonHacks
# See license
# Using a CSI camera (such as the Raspberry Pi Version 2) connected to a
# NVIDIA Jetson Nano Developer Kit using OpenCV
# Drivers for the camera and OpenCV are included in the base image

import cv2
import os

# gstreamer_pipeline returns a GStreamer pipeline for capturing from the CSI camera
# Defaults to 1280x720 @ 60fps
# Flip the image by setting the flip_method (most common values: 0 and 2)
# display_width and display_height determine the size of the window on the screen


def gstreamer_pipeline(
    capture_width=1640,
    capture_height=1232,
    display_width=1640,
    display_height=1232,
    framerate=20,
    flip_method=0,
):
    return (
        "nvarguscamerasrc ! "
        "video/x-raw(memory:NVMM), "
        "width=(int)%d, height=(int)%d, "
        "format=(string)NV12, framerate=(fraction)%d/1 ! "
        "nvvidconv flip-method=%d ! "
        "video/x-raw, width=(int)%d, height=(int)%d, format=(string)BGRx ! "
        "videoconvert ! "
        "video/x-raw, format=(string)BGR ! appsink"
        % (
            capture_width,
            capture_height,
            framerate,
            flip_method,
            display_width,
            display_height,
        )
    )


def show_camera():
    # To flip the image, modify the flip_method parameter (0 and 2 are the most common)
    print(gstreamer_pipeline(flip_method=2))
    cap = cv2.VideoCapture(gstreamer_pipeline(flip_method=0), cv2.CAP_GSTREAMER)
    if cap.isOpened():
        window_handle = cv2.namedWindow("CSI Camera", cv2.WINDOW_AUTOSIZE)
        # Window
        frame_id = 0
        while cv2.getWindowProperty("CSI Camera", 0) >= 0:
            ret_val, img = cap.read()
            cv2.imshow("CSI Camera", img)
            # This also acts as
            k = cv2.waitKey(1) & 0xFF

            if k == ord("q"):
                # ESC pressed
                print("'q' was hit, closing...")
                break
            elif k == ord("s"):
                # s pressed
                image_rgb = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
                img_name = f"VSWRM_img_{frame_id}.jpg"
                cv2.imwrite(img_name, img)
                frame_id += 1
                print(f"{img_name} saved!")
        cap.release()
        cv2.destroyAllWindows()
    else:
        print("Unable to open camera")


if __name__ == "__main__":
    show_camera()