Opencv-在网络摄像头上叠加视频
Opencv-Overlay a Video on Webcam
伙计们，我在将视频叠加到网络摄像头时遇到了问题。我可以毫无问题或错误地打开网络摄像头，但没有显示我的视频。我正在尝试以特定的 x-y 播放我的视频 coordinates.I 从另一个 Whosebug 问题中获取我的大部分代码，但我找不到它知道所以我不能在这里提及它。
有人可以帮我解决这个问题吗？为什么我的视频没有在我的网络摄像头中播放？
我有以下代码：
from os.path import sep
import cv2 as cv2
# load the overlay image. size should be smaller than video frame size
img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
# Start Capture
cap = cv2.VideoCapture(0)
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
frame_vid = img.read()
# Decide X,Y location of overlay image inside video frame.
# following should be valid:
# * image dimensions must be smaller than frame dimensions
# * x+img_width <= frame_width
# * y+img_height <= frame_height
# otherwise you can resize image as part of your code if required
x = 50
y = 50
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# add image to frame
frame[ y:y+width , x:x+height ] = img
'''
tr = 0.3 # transparency between 0-1, show camera if 0
frame = ((1-tr) * frame.astype(np.float) + tr * frame_vid.astype(np.float)).astype(np.uint8)
'''
# Display the resulting frame
cv2.imshow('frame',frame)
# Exit if ESC key is pressed
if cv2.waitKey(20) & 0xFF == 27:
break
cap.release()
cv2.destroyAllWindows()
让我开始一步步分析代码。
- 第 1 步
img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
上面的代码看起来不错，但如果你给出一个字符串名称会更好
video_name = 'photos' + sep + 'Baslksz-3.mp4'
img = cv2.VideoCapture(video_name)
- 第 2 步
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
现在 width 和 height 变量是什么？
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
print(width)
print(height)
结果是：
False
False
您似乎想将 width 和 height 设置为维度 (150, 150)。如果分开初始化就更好了
# Get Image dimensions
img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
width = 150
height = 150
- 第 3 步
# Start Capture
cap = cv2.VideoCapture(0)
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
为什么要初始化 cap 变量两次？
- 第 4 步
frame_vid = img.read()
为什么要初始化frame_vid你在代码的任何地方都没有用到？
- 第 5 步
while (True):
# Capture frame-by-frame
ret, frame = cap.read()
frame[y:y + width, x:x + height] = img
以上代码没有任何意义，只要您的网络摄像头打开，您就想显示您的视频。您也没有检查当前网络摄像头帧是否 returns。您还将 VideoCapture 变量设置为数组？
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
现在你正在取帧，只要你的摄像头是打开的，那么你需要检查摄像头是否有帧returns。如果网络摄像头帧 returns 那么您需要开始读取视频帧。如果视频帧 returns 成功将视频帧大小调整为 (width, height) 然后将其设置为 frame.
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
if ret_video:
# add image to frame
frame_video = cv2.resize(frame_video, (width, height))
frame[y:y + width, x:x + height] = frame_video
- 第 6 步
确保在执行后关闭 img 变量。
img.release()
cap.release()
cv2.destroyAllWindows()
请将 img 变量更改为有意义的值。就像将 img 变量重命名为 video_capture 并将 cap 重命名为 webcam_capture.
When video stops then webcam stacks. But I want to continue infinitive. and video should start again. But video does not starts from beggining.and webcam freezes
更新
Playback loop option in OpenCV videos
中提到了这个问题
看了答案，通过计算视频帧数解决了问题。当视频帧等于捕获帧计数（CAP_PROP_FRAME_COUNT）设置为计数器并且CAP_PROP_FRAME_COUNT为0.
首先初始化帧计数器。
video_frame_counter = 0
当网络摄像头打开时，获取框架。如果帧 returns，则将计数器加 1。
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
video_frame_counter += 1
如果计数器等于捕获的class帧计数，则将两个变量都初始化为0。
if video_frame_counter == img.get(cv2.CAP_PROP_FRAME_COUNT):
video_frame_counter = 0
img.set(cv2.CAP_PROP_POS_FRAMES, 0)
代码：
from os.path import sep
import cv2 as cv2
# load the overlay image. size should be smaller than video frame size
# img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
video_name = 'photos' + sep + 'Baslksz-3.mp4'
img = cv2.VideoCapture(video_name)
# Get Image dimensions
img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
width = 150
height = 150
# Start Capture
cap = cv2.VideoCapture(0)
# cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
# frame_vid = img.read()
# Decide X,Y location of overlay image inside video frame.
# following should be valid:
# * image dimensions must be smaller than frame dimensions
# * x+img_width <= frame_width
# * y+img_height <= frame_height
# otherwise you can resize image as part of your code if required
x = 50
y = 50
video_frame_counter = 0
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
video_frame_counter += 1
if video_frame_counter == img.get(cv2.CAP_PROP_FRAME_COUNT):
video_frame_counter = 0
img.set(cv2.CAP_PROP_POS_FRAMES, 0)
if ret_video:
# add image to frame
frame_video = cv2.resize(frame_video, (width, height))
frame[y:y + width, x:x + height] = frame_video
'''
tr = 0.3 # transparency between 0-1, show camera if 0
frame = ((1-tr) * frame.astype(np.float) + tr * frame_vid.astype(np.float)).astype(np.uint8)
'''
# Display the resulting frame
cv2.imshow('frame', frame)
# Exit if ESC key is pressed
if cv2.waitKey(1) & 0xFF == 27:
break
img.release()
cap.release()
cv2.destroyAllWindows()
伙计们，我在将视频叠加到网络摄像头时遇到了问题。我可以毫无问题或错误地打开网络摄像头，但没有显示我的视频。我正在尝试以特定的 x-y 播放我的视频 coordinates.I 从另一个 Whosebug 问题中获取我的大部分代码，但我找不到它知道所以我不能在这里提及它。
有人可以帮我解决这个问题吗？为什么我的视频没有在我的网络摄像头中播放？ 我有以下代码：
from os.path import sep
import cv2 as cv2
# load the overlay image. size should be smaller than video frame size
img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
# Start Capture
cap = cv2.VideoCapture(0)
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
frame_vid = img.read()
# Decide X,Y location of overlay image inside video frame.
# following should be valid:
# * image dimensions must be smaller than frame dimensions
# * x+img_width <= frame_width
# * y+img_height <= frame_height
# otherwise you can resize image as part of your code if required
x = 50
y = 50
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# add image to frame
frame[ y:y+width , x:x+height ] = img
'''
tr = 0.3 # transparency between 0-1, show camera if 0
frame = ((1-tr) * frame.astype(np.float) + tr * frame_vid.astype(np.float)).astype(np.uint8)
'''
# Display the resulting frame
cv2.imshow('frame',frame)
# Exit if ESC key is pressed
if cv2.waitKey(20) & 0xFF == 27:
break
cap.release()
cv2.destroyAllWindows()
让我开始一步步分析代码。
- 第 1 步
img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
上面的代码看起来不错，但如果你给出一个字符串名称会更好
video_name = 'photos' + sep + 'Baslksz-3.mp4'
img = cv2.VideoCapture(video_name)
- 第 2 步
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
现在 width 和 height 变量是什么？
# Get Image dimensions
width = img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
height = img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
print(width)
print(height)
结果是：
False
False
您似乎想将 width 和 height 设置为维度 (150, 150)。如果分开初始化就更好了
# Get Image dimensions
img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
width = 150
height = 150
- 第 3 步
# Start Capture
cap = cv2.VideoCapture(0)
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
为什么要初始化 cap 变量两次？
- 第 4 步
frame_vid = img.read()
为什么要初始化frame_vid你在代码的任何地方都没有用到？
- 第 5 步
while (True):
# Capture frame-by-frame
ret, frame = cap.read()
frame[y:y + width, x:x + height] = img
以上代码没有任何意义，只要您的网络摄像头打开，您就想显示您的视频。您也没有检查当前网络摄像头帧是否 returns。您还将 VideoCapture 变量设置为数组？
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
现在你正在取帧，只要你的摄像头是打开的，那么你需要检查摄像头是否有帧returns。如果网络摄像头帧 returns 那么您需要开始读取视频帧。如果视频帧 returns 成功将视频帧大小调整为 (width, height) 然后将其设置为 frame.
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
if ret_video:
# add image to frame
frame_video = cv2.resize(frame_video, (width, height))
frame[y:y + width, x:x + height] = frame_video
- 第 6 步
确保在执行后关闭 img 变量。
img.release()
cap.release()
cv2.destroyAllWindows()
请将 img 变量更改为有意义的值。就像将 img 变量重命名为 video_capture 并将 cap 重命名为 webcam_capture.
When video stops then webcam stacks. But I want to continue infinitive. and video should start again. But video does not starts from beggining.and webcam freezes
更新
Playback loop option in OpenCV videos
中提到了这个问题看了答案，通过计算视频帧数解决了问题。当视频帧等于捕获帧计数（CAP_PROP_FRAME_COUNT）设置为计数器并且CAP_PROP_FRAME_COUNT为0.
首先初始化帧计数器。
video_frame_counter = 0
当网络摄像头打开时，获取框架。如果帧 returns，则将计数器加 1。
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
video_frame_counter += 1
如果计数器等于捕获的class帧计数，则将两个变量都初始化为0。
if video_frame_counter == img.get(cv2.CAP_PROP_FRAME_COUNT):
video_frame_counter = 0
img.set(cv2.CAP_PROP_POS_FRAMES, 0)
代码：
from os.path import sep
import cv2 as cv2
# load the overlay image. size should be smaller than video frame size
# img = cv2.VideoCapture('photos' + sep + 'Baslksz-3.mp4')
video_name = 'photos' + sep + 'Baslksz-3.mp4'
img = cv2.VideoCapture(video_name)
# Get Image dimensions
img.set(cv2.CAP_PROP_FRAME_WIDTH, 150) # float `width`
img.set(cv2.CAP_PROP_FRAME_HEIGHT, 150)
width = 150
height = 150
# Start Capture
cap = cv2.VideoCapture(0)
# cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
cap.set(cv2.CAP_PROP_FPS, 30)
# frame_vid = img.read()
# Decide X,Y location of overlay image inside video frame.
# following should be valid:
# * image dimensions must be smaller than frame dimensions
# * x+img_width <= frame_width
# * y+img_height <= frame_height
# otherwise you can resize image as part of your code if required
x = 50
y = 50
video_frame_counter = 0
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
ret_video, frame_video = img.read()
video_frame_counter += 1
if video_frame_counter == img.get(cv2.CAP_PROP_FRAME_COUNT):
video_frame_counter = 0
img.set(cv2.CAP_PROP_POS_FRAMES, 0)
if ret_video:
# add image to frame
frame_video = cv2.resize(frame_video, (width, height))
frame[y:y + width, x:x + height] = frame_video
'''
tr = 0.3 # transparency between 0-1, show camera if 0
frame = ((1-tr) * frame.astype(np.float) + tr * frame_vid.astype(np.float)).astype(np.uint8)
'''
# Display the resulting frame
cv2.imshow('frame', frame)
# Exit if ESC key is pressed
if cv2.waitKey(1) & 0xFF == 27:
break
img.release()
cap.release()
cv2.destroyAllWindows()