Develop Reference

Live dehazed video displayed with opencv, freezes, goes not responding

I want to implement this library with video dehazing ability.
I have only CPU, but I expect the result will be good without GPU,because video output of DCP,or any other dehaze algorithm works good.
So I developed this code:
import cv2
import torch
import numpy as np
import torch.nn as nn
import math
class dehaze_net(nn.Module):
def __init__(self):
super(dehaze_net, self).__init__()
self.relu = nn.ReLU(inplace=True)
self.e_conv1 = nn.Conv2d(3,3,1,1,0,bias=True)
self.e_conv2 = nn.Conv2d(3,3,3,1,1,bias=True)
self.e_conv3 = nn.Conv2d(6,3,5,1,2,bias=True)
self.e_conv4 = nn.Conv2d(6,3,7,1,3,bias=True)
self.e_conv5 = nn.Conv2d(12,3,3,1,1,bias=True)
def forward(self, x):
source = []
source.append(x)
x1 = self.relu(self.e_conv1(x))
x2 = self.relu(self.e_conv2(x1))
concat1 = torch.cat((x1,x2), 1)
x3 = self.relu(self.e_conv3(concat1))
concat2 = torch.cat((x2, x3), 1)
x4 = self.relu(self.e_conv4(concat2))
concat3 = torch.cat((x1,x2,x3,x4),1)
x5 = self.relu(self.e_conv5(concat3))
clean_image = self.relu((x5 * x) - x5 + 1)
return clean_image
model = dehaze_net()
model.load_state_dict(torch.load('snapshots/dehazer.pth',map_location=torch.device('cpu')))
device = torch.device('cpu')
model.to(device)
cap = cv2.VideoCapture(0)
while cap.isOpened():
ret, frame = cap.read()
if ret:
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
frame = torch.from_numpy(frame.transpose((2, 0, 1))).float().unsqueeze(0) / 255.0
frame = frame.to(device)
with torch.no_grad():
dehazed_frame = model(frame).squeeze().cpu().numpy()
dehazed_frame = (dehazed_frame * 255).clip(0, 255).transpose((1, 2, 0)).astype(np.uint8)
dehazed_frame = cv2.cvtColor(dehazed_frame, cv2.COLOR_RGB2BGR)
cv2.imshow('Dehazed Frame', dehazed_frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
cv2.destroyAllWindows()
This is a single file code that needs only snapshots/dehazer.pth to be downloaded from original source(MayankSingal/PyTorch-Image-Dehazing).
I downloaded it and executed the code.
for time being let me show a paper in camera,
The problem:
The problem is
the window that shows the video freezes until it gets a new frame, i.e: Frame1--->FREEZE--->Frame2..., Here is some example:
for 1 second the window looks good
for 5 second the window goes not responding/hangs/freezes...
the window that shows the video, shows the frames with long delay, that is it takes about 5 second for a frame
I was expecting smooth live output(its fine even if Frame-Per-Second is 1 or 2), but I am not ok with that "Not responding" window, I feel the code I/Author have put has some flaw/problem/loop hole. If I use any other code, lik DCP,there is no problem. So whats the part that cause not responding, how to solve?

GUIs need to run their event processing regularly. If that doesn't happen often enough, the GUI becomes noticeably unresponsive. Most operating systems notice that for you and alert you about the program becoming unresponsive.
GUIs are event-based. Any intensive computations must be performed outside of the event loop, i.e. in a thread.
That is not the case in your program because you perform (compute-intensive) inference in the same loop that calls waitKey(), which is the function in OpenCV that performs GUI event processing.
Here is a brief sketch that shows how to use threads:
import cv2 as cv
import threading
import queue
def worker_function(stop_event, result_queue):
cap = cv.VideoCapture()
assert cap.isOpened()
while not stop_event.is_set():
(success, frame) = cap.read()
if not success: break
... # do your inference here
result_queue.put(result_frame)
cap.release()
if __name__ == "__main__":
stop_event = threading.Event()
result_queue = queue.Queue(maxsize=1)
worker_thread = threading.Thread(
target=worker_function, args=(stop_event, result_queue))
worker_thread.start()
cv.namedWindow("window", cv.WINDOW_NORMAL)
while True:
# handle new result, if any
try:
result_frame = result_queue.get_nowait()
cv.imshow("window", result_frame)
result_queue.task_done()
except queue.Empty:
pass
# GUI event processing
key = cv.waitKey(10)
if key in (13, 27): # Enter, Escape
break
stop_event.set()
worker_thread.join()
I didn't test this but the idea is sound.

How to do concurrent executions in python?

Description
I have a file `FaceDetection.py` which detects the face from webcam footage using `opencv` and then writes frames into `output` object, converting it into a video. If the face is present in the frame then a function `sendImg()` is called which then calls the function `faceRec()` from another imported file. At last this method prints the face name if the face is known or prints "unknown".
Problem I am facing
face recognition process is quite expensive and that's why I thought that running from different file and with a thread will create a background process and output.write() function won't be interrupted while doing face recognition. But, as sendImg() function gets called, output.write() function gets interrupted, resulting in skipped frames in saved video.
Resolution I am seeking
I want to do the face recognition without interrupting the output.write() function. So, resulting video will be smooth and no frames would be skipped.
Here is the FaceDetection.py
import threading
from datetime import datetime
import cv2
from FaceRecognition import FaceRecognition
face_cascade = cv2.CascadeClassifier('face_cascade.xml')
fr = FaceRecognition()
img = ""
cap = cv2.VideoCapture(0)
path = 'C:/Users/-- Kanbhaa --/Documents/Recorded/'
vid_name = str("recording_"+datetime.now().strftime("%b-%d-%Y_%H:%M").replace(":","_")+".avi")
vid_cod = cv2.VideoWriter_fourcc(*'MPEG')
output = cv2.VideoWriter( str(path+vid_name) , vid_cod, 20.0 ,(640,480))
def sendImage(imgI):
fr.faceRec(imgI)
while True:
t,img = cap.read()
output.write(img)
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray,2,4)
for _ in faces:
t1 = threading.Thread(target=sendImage,args=(img,))
t1.start()
cv2.imshow('img',img)
if cv2.waitKey(1) & 0XFF == ord('x'):
break
cap.release()
output.release()
Here is the FaceRecognition.py
from simple_facerec import SimpleFacerec
class FaceRecognition:
def __init__(self):
global sfr
# Encode faces from a folder
sfr = SimpleFacerec()
sfr.load_encoding_images("C:/Users/UserName/Documents/FaceRecognitionSystem/images/")
def faceRec(self,frame):
global sfr
# Detect Faces
face_locations, face_names = sfr.detect_known_faces(frame)
for face_loc, name in zip(face_locations, face_names):
if name != "Unknown":
print("known Person detected :) => " + name)
else:
print("Unknown Person detected :( => Frame captured...")
Imported file SimpleFacerec in the above code is from youtube. So, I didn't code it. It can be found below.
SimpleFacerec.py

you write it wrong. It should be
t1 = threading.Thread(target=sendImage, args=(img,))

Try changing, but don't used underscore.
for index in faces:
t1 = threading.Thread(target=sendImage,args=(index,))
t1.start()

Can't write frames to a video with multiprocessing + cv2

I have a code which breaks down a video into frames and edits the image and puts it back into a video, but I am realizing that it's really slow... So I looked into multiprocessing for speeding up the code, and it works! As I can see it processes the images much faster, but the problem is, when I add those frames to a new video, it doesn't work, the video remains empty!
Here is my code:
# Imports
import cv2, sys, time
import numpy as np
from scipy.ndimage import rotate
from PIL import Image, ImageDraw, ImageFont, ImageOps
import concurrent.futures
def function(fullimg):
img = np.array(Image.fromarray(fullimg).crop((1700, 930, 1920-60, 1080-80)))
inpaintRadius = 10
inpaintMethod = cv2.INPAINT_TELEA
textMask = cv2.imread('permanentmask.jpg', 0)
final_result = cv2.inpaint(img.copy(), textMask, inpaintRadius, inpaintMethod)
text = Image.fromarray(np.array([np.array(i) for i in final_result]).astype(np.uint8)).convert('RGBA')
im = np.array([[tuple(x) for x in i] for i in np.zeros((70, 160, 4))])
im[1:-1, 1:-1] = (170, 13, 5, 40)
im[0, :] = (0,0,0,128)
im[1:-1, [0, -1]] = (0,0,0,128)
im[-1, :] = (0,0,0,128)
im = Image.fromarray(im.astype(np.uint8))
draw = ImageDraw.Draw(im)
font = ImageFont.truetype('arialbd.ttf', 57)
draw.text((5, 5),"TEXT",(255,255, 255, 128),font=font)
text.paste(im, mask=im)
text = np.array(text)
fullimg = Image.fromarray(fullimg)
fullimg.paste(Image.fromarray(text), (1700, 930, 1920-60, 1080-80))
fullimg = cv2.cvtColor(np.array(fullimg), cv2.COLOR_BGR2RGB)
return fullimg
cap = cv2.VideoCapture('before2.mp4')
_fourcc = cv2.VideoWriter_fourcc(*'MPEG')
out = cv2.VideoWriter('after.mp4', _fourcc, 29.97, (1280,720))
frames = []
lst = []
while cap.isOpened():
ret, fullimg = cap.read()
if not ret:
break
frames.append(fullimg)
if len(frames) >= 8:
if __name__ == '__main__':
with concurrent.futures.ProcessPoolExecutor() as executor:
results = executor.map(function, frames)
for i in results:
print(type(i))
out.write(i)
frames.clear()
cap.release()
out.release()
cv2.destroyAllWindows() # destroy all opened windows
My code inpaints a watermark and adds another watermark using PIL.
If I don't use multiprocessing the code works. But if I do use multiprocessing, it gives an empty video.

I am not that familiar with OpenCV, but there seems to be a few things that should be corrected in your code. First, if you are running under Windows, as you appear to be because you have if __name__ == '__main__': guarding the code that creates new processes (by the way, when you tag a question with multiprocessing, you should also tag the question with the platform being used), then any code at global scope will be executed by every process created to implement your pool. That means you should move if __name__ == '__main__': as follows:
if __name__ == '__main__':
cap = cv2.VideoCapture('before2.mp4')
_fourcc = cv2.VideoWriter_fourcc(*'MPEG')
out = cv2.VideoWriter('after.mp4', _fourcc, 29.97, (1280,720))
frames = []
lst = []
while cap.isOpened():
ret, fullimg = cap.read()
if not ret:
break
frames.append(fullimg)
if len(frames) >= 8:
with concurrent.futures.ProcessPoolExecutor() as executor:
results = executor.map(function, frames)
for i in results:
print(type(i))
out.write(i)
frames.clear()
cap.release()
out.release()
cv2.destroyAllWindows() # destroy all opened windows
If you do not do this it seems to me that every sub-process in the pool will first attempt in parallel to create an empty video (the function worker function and out.write will never be called by these processes) and only then will the main process be able to invoke the function worker function using map. This doesn't quite explain why the main process doesn't succeed after all of these wasteful attempts. But...
You also have:
while cap.isOpened():
The documentations states that isOpened() returns True if the previous VideoCapture constructor succeeded. Then if this returns True once, why wouldn't it return True the next time it is tested and you end up looping indefinitely? Shouldn't the while be changed to an if? And doesn't this suggest that isOpened() is perhaps returning False or else you would be looping indefinitely? Or what if len(frames) < 8? It seems then you would also end up with an empty output file.
My suggestion would be to make the above changes and try again.
Update
I took a closer look at the code more closely and it appears that it is looping reading the input (before2.mp4) one frame at a time and when it has accumulated 8 frames or more it creates a pool and processes the frames it has accumulated and writing them out to the output (after.mp4). But that means that if there are, for example, 8 more frames, it will create a brand new processing pool (very wasteful and expensive) and then write out the 8 additional processed frames. But if there were only 7 additional frames, they would never get processed and written out. I would suggest the following code (untested, of course):
def main():
import os
cap = cv2.VideoCapture('before2.mp4')
if not cap.isOpened():
return
_fourcc = cv2.VideoWriter_fourcc(*'MPEG')
out = cv2.VideoWriter('after.mp4', _fourcc, 29.97, (1280,720))
FRAMES_AT_A_TIME = 8
pool_size = min(FRAMES_AT_A_TIME, os.cpu_count())
with concurrent.futures.ProcessPoolExecutor(max_workers=pool_size) as executor:
more_frames = True
while more_frames:
frames = []
for _ in range(FRAMES_AT_A_TIME):
ret, fullimg = cap.read()
if not ret:
more_frames = False
break
frames.append(fullimg)
if not frames:
break # no frames
results = executor.map(function, frames)
for i in results:
print(type(i))
out.write(i)
cap.release()
out.release()
cv2.destroyAllWindows() # destroy all opened windows
if __name__ == '__main__':
main()

Python two functions threading

I want to thread two functions, first function streaming a video and passing frames to second function, second function reading frames with Optical Character Recognition and converting frames to text. The question how to pass frames from first threaded function to second threaded function?
What I have done already, with first function saving video frames to local file 'frame.jpg' and at the same time reading with second function from 'frame.jpg'. Is it possible to define video frames as global variable and pass to reading function?
import cv2
import pytesseract
from multiprocessing import Process
def video_straming(): #Video streaming function, First Function
vc = cv2.VideoCapture(0)
cv2.namedWindow("preview")
if vc.isOpened():
rval, frame = vc.read()
else:
rval = False
while rval:
rval, frame = vc.read()
cv2.imwrite('frame.jpg',frame)
key = cv2.waitKey(20)
if key == 27: # exit on ESC
break
cv2.destroyWindow("preview")
def reading(): #Reading from frame.jpg function, Second Function
while:
frame = cv2.imread('frame.jpg')
read = Image.fromarray(frame)
read = pytesseract.image_to_string(read)
if len(read) > 80:
break
if __name__ == '__main__':
video_stream = Process(target=video_streaming)
video_stream.start()
frame_read = Process(target=reading)
frame_read.start()
video_stream.join()
frame_read.join()

Hope this answer can still be of some use.
I use multiprocessing.Pipe() to pass video frames from one processes to another with cv2.VideoCapture() to capture frames and write each image to the Pipe.
import multiprocessing
multiprocessing.set_start_method('spawn')
video_outfrompipe, video_intopipe = multiprocessing.Pipe()
vs = multiprocessing.Process(target=VideoSource, args=(video_intopipe))
vs.start()
vc = multiprocessing.Process(target=VideoConsumer, args=(video_outfrompipe))
vc.start()
vs.join()
vc.join()

openCV and filenames in python

anybody familiar with openCV know how to make it so the output is a different file each time. OR how to make it so the video appends to the original one.
here is the code I am working with
import RPi.GPIO as GPIO
import cv2
import numpy as np
import datetime
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11,GPIO.IN)
import os
# Setup the camera such that it closes
# when we are done with it.
os.chdir ("/home/pi/Videos")
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'MJPG')
while True:
if GPIO.input(11) == 1:
filename = datetime.datetime.now() .strftime ("%Y-%m-%d-%H.%M.%$
print("about to record")
out = cv2.VideoWriter('video.avi', fourcc, 20.0, (640,480))
ret, frame = cap.read()
if ret==True:
out.appendleft(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q') or GPIO.input(11) $
break
else:
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
thanks in advance for any and all help!

This function will store data in a progressive filename system
from os import path
def open_next_file(someData, template='incomingVideo{}.jpg'):
"""Creates a new file for storing new Firmware."""
## Store upto 100 file names
for serial in range(100):
if not path.exists(template.format(serial)):
## if file does not exist,
## enter data into the new file
with open(template.format(serial), 'wb+') as f:
f.write(someData)
break
else:
## if file already exists then,
## don't write on existing files
pass
return template.format(serial)
you can call this function everytime you want to write a new data to a new file viz. incomingVideo1.jpg or incomingVideo2.jpg
You can change the parameters according your needs.
Example
newFile = open_next_file(someDat="Write this inside")
print(newFile)
gives result as incomingVideoX.jpg where x depends on range() function in the loop