Opencv capturing image

Any reference link for this "manually set exposure"

I have changed parameters in code. But, it still taking 5 sec to stable image. I need more guidance.

Problem statement:

I will run code. It will capture image & it will save it.

As soon as I run code, it will stable camera & capture image.

I am using below code.

It still taking 4 to 5 second to stable image.

I am not understanding what parameters to set to get good quality image instantly.

In depth guide needed. Because, I have to attach 6 cameras to our machine

import depthai as dai

import cv2

import time

import os

# ---------------------------

# STEP 1: CREATE THE PIPELINE

# ---------------------------

pipeline = dai.Pipeline()

# --------------------------------------------------

# STEP 2: CREATE & CONFIGURE THE COLOR CAMERA NODE

# --------------------------------------------------

camRgb = pipeline.createColorCamera()

camRgb.setPreviewSize(640, 480) # Increase preview size  (1920, 1080)   (640, 480)

camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_12_MP)

camRgb.setInterleaved(False)

camRgb.setBoardSocket(dai.CameraBoardSocket.CAM_A)

# ----------------------------------------------------------------

# STEP 3: CONFIGURE INITIAL CAMERA SETTINGS (EXPOSURE, FOCUS, ISO)

# ----------------------------------------------------------------

camRgb.initialControl.setAutoFocusMode(dai.CameraControl.AutoFocusMode.CONTINUOUS_VIDEO)

camRgb.initialControl.setManualExposure(50000, 300)

# ---------------------------------------------------

# STEP 4: CREATE AN OUTPUT (XLinkOut) TO STREAM FRAMES

# ---------------------------------------------------

xoutPreview = pipeline.createXLinkOut()

xoutPreview.setStreamName("preview")

camRgb.preview.link(xoutPreview.input)

# -------------------------------------

# STEP 5: START THE PIPELINE ON DEVICE

# -------------------------------------

with dai.Device(pipeline) as device:

    previewQueue = device.getOutputQueue(name="preview", maxSize=4, blocking=False)

    print("Press 's' to save an image larger than 5MB, 'q' to quit the program.")

    while True:

        inPreview = previewQueue.tryGet()

        if inPreview is not None:

            frame = inPreview.getCvFrame()

            cv2.imshow("preview", frame)

            cv2.imwrite("output_images1\\preview.png", frame)

        key = cv2.waitKey(1) & 0xFF

        if key == ord('s'):

            if 'frame' in locals():

                timestamp = time.strftime("%Y%m%d_%H%M%S")

                filename = f"D:\\oak_kit\\example\\output_imgaes1\\6_feb_25\\capture{timestamp}.bmp" #filename = f"D:\\oak_kit\\example\\output_images1\\6_feb_25\\capture{timestamp}.bmp"

                cv2.imwrite(filename, frame)

                # Check the file size

                file_size = os.path.getsize(filename)

                if file_size > 5 * 1024 * 1024:  # 5MB in bytes

                    print(f"Image saved: {filename} (Size: {file_size / (1024 * 1024)} MB)")

                else:

                    os.remove(filename)

                    print(f"Image discarded: {filename} (Size: {file_size / (1024 * 1024)} MB)")

            else:

                print("No frame to save yet.")

        elif key == ord('q'):

            print("Quitting...")

            break

    cv2.destroyAllWindows()

We are getting good result for small frame (500*500).

But, for big frames it is taking time to stable camera. Around 6 sec.

I need to capture big frames (1500*800) as soon as I run codes

Below is code we use for big frames.

            cv2.imshow("preview", frame)

            cv2.imwrite("output_imgaes1\\preview.png", frame)

        key = cv2.waitKey(1) & 0xFF

        if key == ord('s'):

            if 'frame' in locals():

                timestamp = time.strftime("%Y%m%d_%H%M%S")

                filename = f"D:\\oak_kit\\example\\output_imgaes1\\8_feb_25\\capture_{timestamp}.bmp"

                cv2.imwrite(filename, frame)

                print(f"Image saved: {filename}")

            else:

                print("No frame to save yet.")

        elif key == ord('q'):

            print("Quitting...")

            break

    cv2.destroyAllWindows()

we have done latency test. As given in link here, OAK bandwidth test - Should be around 800/200 Mbps.

But I am getting as per attached in screenshot.

Does screen value is correct or do we need to update hardware (POE switch / cable)

poe_test.py gives all OK results.

Finally we have use below code by changing CAT 6 good quality ethernet cable.

Now problem is, for below code after running code, we are getting below warning on console & it is taking 8 sec to show video frame.

[2025-02-10 16:48:16.272] [depthai] [warning] [18443010F15F9D0F00] [192.168.31.197] Flashed bootloader version 0.0.22, less than 0.0.28 is susceptible to bootup/restart failure. Upgrading is advised, flashing main/factory (not user) bootloader. Available: 0.0.28
Press 's' to save an image, 'q' to quit the program.

import depthai as dai

import cv2

import time

# ---------------------------

# STEP 1: CREATE THE PIPELINE

# ---------------------------

pipeline = dai.Pipeline()

# --------------------------------------------------

# STEP 2: CREATE & CONFIGURE THE COLOR CAMERA NODE

# --------------------------------------------------

camRgb = pipeline.createColorCamera()

camRgb.setPreviewSize(640, 480) # camRgb.setPreviewSize(400, 300) # (500, 500) (1080, 480) camRgb.setPreviewSize(1920, 1080) camRgb.setPreviewSize(640, 480)

camRgb.setInterleaved(False)

# Sets the sensor to 4K mode (maximum sensor resolution around 3840x2160 or slightly more)

camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_12_MP)

# WARNING DEPRECATION: 'RGB' is deprecated; use 'CAM_A' (or whichever is your color socket)

camRgb.setBoardSocket(dai.CameraBoardSocket.CAM_A)

# ----------------------------------------------------------------

# STEP 3: CONFIGURE INITIAL CAMERA SETTINGS (EXPOSURE, FOCUS, ISO)

# ----------------------------------------------------------------

# Instead of creating a separate CameraControl and setting a commandList,

# we directly set the camera's initial control properties here:

camRgb.initialControl.setAutoFocusMode(dai.CameraControl.AutoFocusMode.CONTINUOUS_PICTURE) # CONTINUOUS_PICTURE

# Manual exposure: 20,000 µs = 20 ms, ISO = 200

camRgb.initialControl.setManualExposure(200, 400) # (100000, 500) (200000, 300)

camRgb.initialControl.setManualFocus(130)

camRgb.initialControl.setManualWhiteBalance(5834)

# ---------------------------------------------------

# STEP 4: CREATE AN OUTPUT (XLinkOut) TO STREAM FRAMES

# ---------------------------------------------------

xoutPreview = pipeline.createXLinkOut()

xoutPreview.setStreamName("preview")

camRgb.preview.link(xoutPreview.input)

# -------------------------------------

# STEP 5: START THE PIPELINE ON DEVICE

# -------------------------------------

with dai.Device(pipeline) as device:

previewQueue = device.getOutputQueue(name="preview", maxSize=4, blocking=False)

print("Press 's' to save an image, 'q' to quit the program.")

while True:

    inPreview = previewQueue.tryGet()

    if inPreview is not None:

        frame = inPreview.getCvFrame()

        cv2.imshow("preview", frame)

        cv2.imwrite("output_imgaes1\\\\preview.png", frame)

    key = cv2.waitKey(1) & 0xFF

    if key == ord('s'):

        if 'frame' in locals():

            timestamp = time.strftime("%Y%m%d_%H%M%S")

            filename = f"D:\\\\oak_kit\\\\example\\\\output_imgaes1\\\\10_feb_25\\\\capture_{timestamp}.bmp"

            cv2.imwrite(filename, frame)

            print(f"Image saved: {filename}")

        else:

            print("No frame to save yet.")

    elif key == ord('q'):

        print("Quitting...")

        break

cv2.destroyAllWindows()

jakaskerl

Bootloader is updated & now bootloader warning is not coming.

But, I am not able to understand below things. As per documentation,

Customizing the Watchdog Timeout

Set the environment variablesDEPTHAI_WATCHDOG_INITIAL_DELAYandDEPTHAI_BOOTUP_TIMEOUTto your desired timeout values (in milliseconds) as follows:

Alternatively, you can set the timeout directly in your code:

Python

$$
1pipeline = depthai.Pipeline()
2
3# Create a BoardConfig object
4config = depthai.BoardConfig()
5
6# Set the parameters
7config.watchdogInitialDelayMs = <my_value>
8config.watchdogTimeoutMs = <my_value>
9
10pipeline.setBoardConfig(config)
$$

By adjusting these settings, you can tailor the watchdog functionality to better suit your specific requirements.

I have put 1 sec (1000), but its not reducing any time.

Any link to understand this in depth. I have to capture images in microseconds. Instead of POE, do I need to use power supply for this.

Since, for device reconnection time is 10 seconds(whether it is POE or we give supply from power cable), do I need to follow below steps.

1: Once our machine is ON, python code will be called & camera video streaming will be playing.

2: Once our software get external trigger, it will capture image & keep video streaming running till it get next trigger.

Every time it get trigger, it will capture images.

In this, way, camera will be remain ON 24 hours in video mode & whenever we want we can capture images.

is this understanding is true?

What we need?

1: Machine will be ON. Once our software got external trigger, it will run python code. But everytime it call python code,

reconnection will take 10 seconds. we have to reduce this 10 seconds.