OpenCV VideoCapture 和错误:(-215:断言失败)!_src.empty() in function 'cv::cvtColor'
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【中文标题】OpenCV VideoCapture 和错误:(-215:断言失败)!_src.empty() in function \'cv::cvtColor\'【英文标题】:OpenCV VideoCapture and error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'OpenCV VideoCapture 和错误:(-215:断言失败)!_src.empty() in function 'cv::cvtColor' 【发布时间】:2022-01-10 14:49:43 【问题描述】:目前使用 Windows 10 和 Python 3.7 我尝试使用此代码运行,以使网络摄像头能够用于数字识别
def get_img_contour_thresh(img):
x, y, w, h = 0, 0, 300, 300
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (5, 5), 0)
ret, thresh1 = cv2.threshold(blur, 175, 255, cv2.THRESH_BINARY_INV +
cv2.THRESH_OTSU)
thresh1 = thresh1[y:y + h, x:x + w]
contours, hierarchy = cv2.findContours(thresh1, cv2.RETR_TREE,
cv2.CHAIN_APPROX_SIMPLE)[-2:]
return img, contours, thresh1
def show_webcam(mirror=False):
# load json and create model
json_file = open('model.json', 'r')
loaded_model_json = json_file.read()
json_file.close()
model = model_from_json(loaded_model_json)
# load weights into new model
model.load_weights("model.h5")
print("Loaded model from disk")
model.compile(loss='categorical_crossentropy',
optimizer='adam',
metrics=['accuracy'])
cap = cv2.VideoCapture(0)
while True:
ret, img = cap.read()
img, contours, thresh = get_img_contour_thresh(img)
ans = ''
if len(contours) > 0:
contour = max(contours, key=cv2.contourArea)
if cv2.contourArea(contour) > 500:
x, y, w, h = cv2.boundingRect(contour)
newImage = thresh[y:y + h, x:x + w]
newImage = cv2.resize(newImage, (28, 28))
newImage = np.array(newImage)
newImage = newImage.astype('float32')
newImage /= 255
if K.image_data_format() == 'channels_first':
newImage = newImage.reshape(1, 28, 28)
else:
newImage = newImage.reshape(28, 28, 1)
newImage = np.expand_dims(newImage, axis=0)
ans = model.predict(newImage).argmax()
x, y, w, h = 0, 0, 300, 300
cv2.rectangle(img, (x, y), (x + w, y + h), (0, 255, 0), 2)
cv2.putText(img, "CNN : " + str(ans), (10, 320),
cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)
cv2.imshow("Frame", img)
cv2.imshow("Contours", thresh)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
def main():
show_webcam(mirror=True)
if __name__ == '__main__':
main()
我收到此错误
File "cam.py", line 75, in <module>
main()
File "cam.py", line 71, in main
show_webcam(mirror=True)
File "cam.py", line 34, in show_webcam
img, contours, thresh = get_img_contour_thresh(img)
File "cam.py", line 10, in get_img_contour_thresh
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
cv2.error: OpenCV(3.4.4) C:\projects\opencv-
python\opencv\modules\imgproc\src\color.cpp:181: error: (-215:Assertion
failed) !_src.empty() in function 'cv::cvtColor'
我一直在寻找解决方案,但没有任何运气解决这个问题,尝试环顾四周但无法弄清楚,你们怎么看?感谢提供的帮助
【问题讨论】:
检查您的相机并确保它已连接。 【参考方案1】:如果None
被传递给cv2.cvtColor
,就会发生错误。
之后
ret, img = cap.read()
在继续之前检查img is not None
是个好主意。根据您的输入源,cap.read()
可能会失败。在我的一台笔记本电脑上,它在开始返回有效图像之前至少失败了一次。
【讨论】:
最好改为检查if not ret: break
。这就是它的用途。在创建 VideoCapture 实例后检查一次cap.isOpened()
也是一个好主意以上是关于OpenCV VideoCapture 和错误:(-215:断言失败)!_src.empty() in function 'cv::cvtColor'的主要内容,如果未能解决你的问题,请参考以下文章
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