imwrite error

[doyle011]

error: OpenCV(4.8.0) D:\a\opencv-python\opencv-python\opencv\modules\imgcodecs\src\loadsave.cpp:787: error: (-215:Assertion failed) !_img.empty() in function 'cv::imwrite'

[kumaranshu8092]

that is because the "ret" is getting the false value in line 4.

in the 1st line cap = cv2.VideoCapture(camera_number) you have to enter the correct camera_number after checking the configuration...i had connected my mobile as a camera through DroidCam so my camera_number was "0"

[Kienvu175]

same me :)) follow Nick then faced this issue. Solution is to change cap = cv2.VideoCapture(1) => cap = cv2.VideoCapture(0)

[AmanJ10]

Despite having the correct video capture device number, I'm still encountering this error.

[TAREK-ESSAM-22]

I had the same error but I discovered that the problem in the permissions of the camera of the laptop , may be from the windows or not so I used the mobile cam instead to collect the image , you should download an app on mobile called IP webcam

here is the code

import urllib.request #for mobile cam
#collect img from mobile cam
​

URL of the IP webcam stream

url = "URL of your web cam/shot.jpg"
​

Root directory to save captured images

ROOT_DIR = "data"
IMAGES_DIR = os.path.join(ROOT_DIR, "images")
os.makedirs(IMAGES_DIR, exist_ok=True)
​
for imgnum in range(number_images):
# Read the image from the URL
img_arr = np.array(bytearray(urllib.request.urlopen(url).read()), dtype=np.uint8)
img = cv2.imdecode(img_arr, -1)
​
# Generate a unique filename for the captured image
imgname = os.path.join(IMAGES_DIR, f'{str(uuid.uuid1())}.jpg')
​
# Save the captured image
cv2.imwrite(imgname, img)
​
print(f"Image {imgnum + 1} captured and saved as {imgname}")
​
# Wait for a short time before capturing the next image
time.sleep(0.5)
​
print("Image capture process complete.")
​

[Somurahwa]

Epoch 1/10

ValueError Traceback (most recent call last)
Cell In[74], line 1
----> 1 hist = model.fit(train, epochs=10, validation_data=val, callbacks=[tensorboard_callback])

File ~\Desktop\Panashe\tensorflow\TFODCourse\murahwa\Lib\site-packages\keras-3.1.1-py3.11.egg\keras\src\utils\traceback_utils.py:122, in filter_traceback..error_handler(*args, **kwargs)
119 filtered_tb = _process_traceback_frames(e.traceback)
120 # To get the full stack trace, call:
121 # keras.config.disable_traceback_filtering()
--> 122 raise e.with_traceback(filtered_tb) from None
123 finally:
124 del filtered_tb

Cell In[68], line 19, in FaceTracker.train_step(self, batch, **kwargs)
16 with tf.GradientTape() as tape:
17 classes, coords = self.model(X, training=True)
---> 19 batch_classloss = self.closs(y[0], classes)
20 batch_localizationloss = self.lloss(tf.cast(y[1], tf.float32), coords)
22 total_loss = batch_localizationloss+0.5*batch_classloss

ValueError: Cannot take the length of shape with unknown rank.