PytQt5 GUI design and Video processing with OpenCV

 · 27 mins read



Hello friends, today we will design a very basic GUI that will use the Model-View-Controller approach for the video processing applications. The user can change blur and brightness of the video frames and take pictures to save images. Additional text labels are also part of this tutorial as shown in the code. You will notice how the code is reused here from the Tutorial 05 of PyQt5 learning series.

Requirements

cv2 pyshine numpy

pip3 install opencv-contrib-python
pip3 install pyshine
pip3 install numpy
pip3 install PyQt5
pip3 install imutils

To detect face, we require a cascasdeClassifier xml file. The main Python code is here, by default it will use the webcam of your pc to process video. For a video file, set the cam = False, and put a video file in the same folder as the Python code below. Also the xml file should be in the same folder as shown in the video.

Updated version with Start/Stop toggle button is added based on the suggestion from Ilker. This is the updated version 2.

process_version2.py


# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'process.ui'
#
# Created by: PyQt5 UI code generator 5.11.3
#
# WARNING! All changes made in this file will be lost!
#
# Subscribe to PyShine Youtube channel for more detail! 

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QFileDialog
from PyQt5.QtGui import QImage
import cv2, imutils
import time
import numpy as np
faceCascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
import numpy as np
import cv2
import pyshine as ps


class Ui_MainWindow(object):
	def setupUi(self, MainWindow):
		MainWindow.setObjectName("MainWindow")
		MainWindow.resize(498, 522)
		self.centralwidget = QtWidgets.QWidget(MainWindow)
		self.centralwidget.setObjectName("centralwidget")
		self.gridLayout_2 = QtWidgets.QGridLayout(self.centralwidget)
		self.gridLayout_2.setObjectName("gridLayout_2")
		self.horizontalLayout = QtWidgets.QHBoxLayout()
		self.horizontalLayout.setObjectName("horizontalLayout")
		self.label = QtWidgets.QLabel(self.centralwidget)
		self.label.setText("")
		self.label.setPixmap(QtGui.QPixmap("images/H.png"))
		self.label.setObjectName("label")
		self.horizontalLayout.addWidget(self.label)
		self.gridLayout = QtWidgets.QGridLayout()
		self.gridLayout.setObjectName("gridLayout")
		self.verticalSlider = QtWidgets.QSlider(self.centralwidget)
		self.verticalSlider.setOrientation(QtCore.Qt.Vertical)
		self.verticalSlider.setObjectName("verticalSlider")
		self.gridLayout.addWidget(self.verticalSlider, 0, 0, 1, 1)
		self.verticalSlider_2 = QtWidgets.QSlider(self.centralwidget)
		self.verticalSlider_2.setOrientation(QtCore.Qt.Vertical)
		self.verticalSlider_2.setObjectName("verticalSlider_2")
		self.gridLayout.addWidget(self.verticalSlider_2, 0, 1, 1, 1)
		self.label_2 = QtWidgets.QLabel(self.centralwidget)
		self.label_2.setAlignment(QtCore.Qt.AlignCenter)
		self.label_2.setObjectName("label_2")
		self.gridLayout.addWidget(self.label_2, 1, 0, 1, 1)
		self.label_3 = QtWidgets.QLabel(self.centralwidget)
		self.label_3.setAlignment(QtCore.Qt.AlignCenter)
		self.label_3.setObjectName("label_3")
		self.gridLayout.addWidget(self.label_3, 1, 1, 1, 1)
		self.horizontalLayout.addLayout(self.gridLayout)
		self.gridLayout_2.addLayout(self.horizontalLayout, 0, 0, 1, 2)
		self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
		self.horizontalLayout_2.setObjectName("horizontalLayout_2")
		self.pushButton = QtWidgets.QPushButton(self.centralwidget)
		self.pushButton.setObjectName("pushButton")
		self.horizontalLayout_2.addWidget(self.pushButton)
		self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
		self.pushButton_2.setObjectName("pushButton_2")
		self.horizontalLayout_2.addWidget(self.pushButton_2)
		self.gridLayout_2.addLayout(self.horizontalLayout_2, 1, 0, 1, 1)
		spacerItem = QtWidgets.QSpacerItem(313, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
		self.gridLayout_2.addItem(spacerItem, 1, 1, 1, 1)
		MainWindow.setCentralWidget(self.centralwidget)
		self.statusbar = QtWidgets.QStatusBar(MainWindow)
		self.statusbar.setObjectName("statusbar")
		MainWindow.setStatusBar(self.statusbar)

		self.retranslateUi(MainWindow)
		self.verticalSlider.valueChanged['int'].connect(self.brightness_value)
		self.verticalSlider_2.valueChanged['int'].connect(self.blur_value)
		self.pushButton_2.clicked.connect(self.loadImage)
		self.pushButton.clicked.connect(self.savePhoto)
		QtCore.QMetaObject.connectSlotsByName(MainWindow)
		
		# Added code here
		self.filename = 'Snapshot '+str(time.strftime("%Y-%b-%d at %H.%M.%S %p"))+'.png' # Will hold the image address location
		self.tmp = None # Will hold the temporary image for display
		self.brightness_value_now = 0 # Updated brightness value
		self.blur_value_now = 0 # Updated blur value
		self.fps=0
		self.started = False
	
	def loadImage(self):
		""" This function will load the camera device, obtain the image
			and set it to label using the setPhoto function
		"""
		if self.started:
			self.started=False
			self.pushButton_2.setText('Start')	
		else:
			self.started=True
			self.pushButton_2.setText('Stop')
		
		cam = True # True for webcam
		if cam:
			vid = cv2.VideoCapture(0)
		else:
			vid = cv2.VideoCapture('video.mp4')
		
		cnt=0
		frames_to_count=20
		st = 0
		fps=0
		
		while(vid.isOpened()):
			
			img, self.image = vid.read()
			self.image  = imutils.resize(self.image ,height = 480 )
			
			gray = cv2.cvtColor(self.image, cv2.COLOR_BGR2GRAY) 
			faces = faceCascade.detectMultiScale(
			gray,
			scaleFactor=1.15,  
			minNeighbors=7, 
			minSize=(80, 80), 
			flags=cv2.CASCADE_SCALE_IMAGE)
			
			for (x, y, w, h) in faces:
				cv2.rectangle(self.image, (x, y), (x + w, y + h), (10, 228,220), 5) 
			
			if cnt == frames_to_count:
				try: # To avoid divide by 0 we put it in try except
					print(frames_to_count/(time.time()-st),'FPS') 
					self.fps = round(frames_to_count/(time.time()-st)) 
					
					
					st = time.time()
					cnt=0
				except:
					pass
			
			cnt+=1
			
			self.update()
			key = cv2.waitKey(1) & 0xFF
			if self.started==False:
				break
				print('Loop break')
	
	def setPhoto(self,image):
		""" This function will take image input and resize it 
			only for display purpose and convert it to QImage
			to set at the label.
		"""
		self.tmp = image
		image = imutils.resize(image,width=640)
		frame = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
		image = QImage(frame, frame.shape[1],frame.shape[0],frame.strides[0],QImage.Format_RGB888)
		self.label.setPixmap(QtGui.QPixmap.fromImage(image))
	
	def brightness_value(self,value):
		""" This function will take value from the slider
			for the brightness from 0 to 99
		"""
		self.brightness_value_now = value
		print('Brightness: ',value)
		self.update()
		
		
	def blur_value(self,value):
		""" This function will take value from the slider 
			for the blur from 0 to 99 """
		self.blur_value_now = value
		print('Blur: ',value)
		self.update()
	
	
	def changeBrightness(self,img,value):
		""" This function will take an image (img) and the brightness
			value. It will perform the brightness change using OpenCv
			and after split, will merge the img and return it.
		"""
		hsv = cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
		h,s,v = cv2.split(hsv)
		lim = 255 - value
		v[v>lim] = 255
		v[v<=lim] += value
		final_hsv = cv2.merge((h,s,v))
		img = cv2.cvtColor(final_hsv,cv2.COLOR_HSV2BGR)
		return img
		
	def changeBlur(self,img,value):
		""" This function will take the img image and blur values as inputs.
			After perform blur operation using opencv function, it returns 
			the image img.
		"""
		kernel_size = (value+1,value+1) # +1 is to avoid 0
		img = cv2.blur(img,kernel_size)
		return img
	
	def update(self):
		""" This function will update the photo according to the 
			current values of blur and brightness and set it to photo label.
		"""
		img = self.changeBrightness(self.image,self.brightness_value_now)
		img = self.changeBlur(img,self.blur_value_now)

		# Here we add display text to the image
		text  =  'FPS: '+str(self.fps)
		img = ps.putBText(img,text,text_offset_x=20,text_offset_y=30,vspace=20,hspace=10, font_scale=1.0,background_RGB=(10,20,222),text_RGB=(255,255,255))
		text = str(time.strftime("%H:%M %p"))
		img = ps.putBText(img,text,text_offset_x=self.image.shape[1]-180,text_offset_y=30,vspace=20,hspace=10, font_scale=1.0,background_RGB=(228,20,222),text_RGB=(255,255,255))
		text  =  f"Brightness: {self.brightness_value_now}"
		img = ps.putBText(img,text,text_offset_x=80,text_offset_y=425,vspace=20,hspace=10, font_scale=1.0,background_RGB=(20,210,4),text_RGB=(255,255,255))
		text  =  f'Blur: {self.blur_value_now}: '
		img = ps.putBText(img,text,text_offset_x=self.image.shape[1]-200,text_offset_y=425,vspace=20,hspace=10, font_scale=1.0,background_RGB=(210,20,4),text_RGB=(255,255,255))


		self.setPhoto(img)
	
	def savePhoto(self):
		""" This function will save the image"""
		self.filename = 'Snapshot '+str(time.strftime("%Y-%b-%d at %H.%M.%S %p"))+'.png'
		cv2.imwrite(self.filename,self.tmp)
		print('Image saved as:',self.filename)
	
	
	def retranslateUi(self, MainWindow):
		_translate = QtCore.QCoreApplication.translate
		MainWindow.setWindowTitle(_translate("MainWindow", "PyShine video process"))
		self.pushButton_2.setText(_translate("MainWindow", "Start"))
		self.label_2.setText(_translate("MainWindow", "Brightness"))
		self.label_3.setText(_translate("MainWindow", "Blur"))
		self.pushButton.setText(_translate("MainWindow", "Take picture"))

# Subscribe to PyShine Youtube channel for more detail! 

# WEBSITE: www.pyshine.com


if __name__ == "__main__":
	import sys
	app = QtWidgets.QApplication(sys.argv)
	MainWindow = QtWidgets.QMainWindow()
	ui = Ui_MainWindow()
	ui.setupUi(MainWindow)
	MainWindow.show()
	sys.exit(app.exec_())



Following is the old version 1.

process_version1.py


# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'process.ui'
#
# Created by: PyQt5 UI code generator 5.11.3
#
# WARNING! All changes made in this file will be lost!
#
# Subscribe to PyShine Youtube channel for more detail! 

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QFileDialog
from PyQt5.QtGui import QImage
import cv2, imutils
import time
import numpy as np
faceCascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
import numpy as np
import cv2
import pyshine as ps


class Ui_MainWindow(object):
	def setupUi(self, MainWindow):
		MainWindow.setObjectName("MainWindow")
		MainWindow.resize(498, 522)
		self.centralwidget = QtWidgets.QWidget(MainWindow)
		self.centralwidget.setObjectName("centralwidget")
		self.gridLayout_2 = QtWidgets.QGridLayout(self.centralwidget)
		self.gridLayout_2.setObjectName("gridLayout_2")
		self.horizontalLayout = QtWidgets.QHBoxLayout()
		self.horizontalLayout.setObjectName("horizontalLayout")
		self.label = QtWidgets.QLabel(self.centralwidget)
		self.label.setText("")
		self.label.setPixmap(QtGui.QPixmap("images/H.png"))
		self.label.setObjectName("label")
		self.horizontalLayout.addWidget(self.label)
		self.gridLayout = QtWidgets.QGridLayout()
		self.gridLayout.setObjectName("gridLayout")
		self.verticalSlider = QtWidgets.QSlider(self.centralwidget)
		self.verticalSlider.setOrientation(QtCore.Qt.Vertical)
		self.verticalSlider.setObjectName("verticalSlider")
		self.gridLayout.addWidget(self.verticalSlider, 0, 0, 1, 1)
		self.verticalSlider_2 = QtWidgets.QSlider(self.centralwidget)
		self.verticalSlider_2.setOrientation(QtCore.Qt.Vertical)
		self.verticalSlider_2.setObjectName("verticalSlider_2")
		self.gridLayout.addWidget(self.verticalSlider_2, 0, 1, 1, 1)
		self.label_2 = QtWidgets.QLabel(self.centralwidget)
		self.label_2.setAlignment(QtCore.Qt.AlignCenter)
		self.label_2.setObjectName("label_2")
		self.gridLayout.addWidget(self.label_2, 1, 0, 1, 1)
		self.label_3 = QtWidgets.QLabel(self.centralwidget)
		self.label_3.setAlignment(QtCore.Qt.AlignCenter)
		self.label_3.setObjectName("label_3")
		self.gridLayout.addWidget(self.label_3, 1, 1, 1, 1)
		self.horizontalLayout.addLayout(self.gridLayout)
		self.gridLayout_2.addLayout(self.horizontalLayout, 0, 0, 1, 2)
		self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
		self.horizontalLayout_2.setObjectName("horizontalLayout_2")
		self.pushButton = QtWidgets.QPushButton(self.centralwidget)
		self.pushButton.setObjectName("pushButton")
		self.horizontalLayout_2.addWidget(self.pushButton)
		self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
		self.pushButton_2.setObjectName("pushButton_2")
		self.horizontalLayout_2.addWidget(self.pushButton_2)
		self.gridLayout_2.addLayout(self.horizontalLayout_2, 1, 0, 1, 1)
		spacerItem = QtWidgets.QSpacerItem(313, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
		self.gridLayout_2.addItem(spacerItem, 1, 1, 1, 1)
		MainWindow.setCentralWidget(self.centralwidget)
		self.statusbar = QtWidgets.QStatusBar(MainWindow)
		self.statusbar.setObjectName("statusbar")
		MainWindow.setStatusBar(self.statusbar)

		self.retranslateUi(MainWindow)
		self.verticalSlider.valueChanged['int'].connect(self.brightness_value)
		self.verticalSlider_2.valueChanged['int'].connect(self.blur_value)
		self.pushButton_2.clicked.connect(self.loadImage)
		self.pushButton.clicked.connect(self.savePhoto)
		QtCore.QMetaObject.connectSlotsByName(MainWindow)
		
		# Added code here
		self.filename = 'Snapshot '+str(time.strftime("%Y-%b-%d at %H.%M.%S %p"))+'.png' # Will hold the image address location
		self.tmp = None # Will hold the temporary image for display
		self.brightness_value_now = 0 # Updated brightness value
		self.blur_value_now = 0 # Updated blur value
		self.fps=0
	
	def loadImage(self):
		""" This function will load the camera device, obtain the image
			and set it to label using the setPhoto function
		"""
		cam = True # True for webcam
		if cam:
			vid = cv2.VideoCapture(0)
		else:
			vid = cv2.VideoCapture('video.mp4') # place path to your video file here
		cnt=0
		frames_to_count=20
		st = 0
		fps=0
		
		while(vid.isOpened()):
	
			img, self.image = vid.read()
			self.image  = imutils.resize(self.image ,height = 480 )
			
			gray = cv2.cvtColor(self.image, cv2.COLOR_BGR2GRAY) 
			faces = faceCascade.detectMultiScale(
			gray,
			scaleFactor=1.15,  
			minNeighbors=7, 
			minSize=(80, 80), 
			flags=cv2.CASCADE_SCALE_IMAGE)
			
			for (x, y, w, h) in faces:
				cv2.rectangle(self.image, (x, y), (x + w, y + h), (10, 228,220), 5) 
			
			if cnt == frames_to_count:
				try: # To avoid divide by 0 we put it in try except
					print(frames_to_count/(time.time()-st),'FPS') 
					self.fps = round(frames_to_count/(time.time()-st)) 
					
					
					st = time.time()
					cnt=0
				except:
					pass
			
			cnt+=1
			
			self.update()
			key = cv2.waitKey(1) & 0xFF
			if key == ord("q"):
				break
	
	def setPhoto(self,image):
		""" This function will take image input and resize it 
			only for display purpose and convert it to QImage
			to set at the label.
		"""
		self.tmp = image
		image = imutils.resize(image,width=640)
		frame = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
		image = QImage(frame, frame.shape[1],frame.shape[0],frame.strides[0],QImage.Format_RGB888)
		self.label.setPixmap(QtGui.QPixmap.fromImage(image))
	
	def brightness_value(self,value):
		""" This function will take value from the slider
			for the brightness from 0 to 99
		"""
		self.brightness_value_now = value
		print('Brightness: ',value)
		self.update()
		
		
	def blur_value(self,value):
		""" This function will take value from the slider 
			for the blur from 0 to 99 """
		self.blur_value_now = value
		print('Blur: ',value)
		self.update()
	
	
	def changeBrightness(self,img,value):
		""" This function will take an image (img) and the brightness
			value. It will perform the brightness change using OpenCv
			and after split, will merge the img and return it.
		"""
		hsv = cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
		h,s,v = cv2.split(hsv)
		lim = 255 - value
		v[v>lim] = 255
		v[v<=lim] += value
		final_hsv = cv2.merge((h,s,v))
		img = cv2.cvtColor(final_hsv,cv2.COLOR_HSV2BGR)
		return img
		
	def changeBlur(self,img,value):
		""" This function will take the img image and blur values as inputs.
			After perform blur operation using opencv function, it returns 
			the image img.
		"""
		kernel_size = (value+1,value+1) # +1 is to avoid 0
		img = cv2.blur(img,kernel_size)
		return img
	
	def update(self):
		""" This function will update the photo according to the 
			current values of blur and brightness and set it to photo label.
		"""
		img = self.changeBrightness(self.image,self.brightness_value_now)
		img = self.changeBlur(img,self.blur_value_now)

		# Here we add display text to the image
		text  =  'FPS: '+str(self.fps)
		img = ps.putBText(img,text,text_offset_x=20,text_offset_y=30,vspace=20,hspace=10, font_scale=1.0,background_RGB=(10,20,222),text_RGB=(255,255,255))
		text = str(time.strftime("%H:%M %p"))
		img = ps.putBText(img,text,text_offset_x=self.image.shape[1]-180,text_offset_y=30,vspace=20,hspace=10, font_scale=1.0,background_RGB=(228,20,222),text_RGB=(255,255,255))
		text  =  f"Brightness: {self.brightness_value_now}"
		img = ps.putBText(img,text,text_offset_x=80,text_offset_y=425,vspace=20,hspace=10, font_scale=1.0,background_RGB=(20,210,4),text_RGB=(255,255,255))
		text  =  f'Blur: {self.blur_value_now}: '
		img = ps.putBText(img,text,text_offset_x=self.image.shape[1]-200,text_offset_y=425,vspace=20,hspace=10, font_scale=1.0,background_RGB=(210,20,4),text_RGB=(255,255,255))


		self.setPhoto(img)
	
	def savePhoto(self):
		""" This function will save the image"""
		self.filename = 'Snapshot '+str(time.strftime("%Y-%b-%d at %H.%M.%S %p"))+'.png'
		cv2.imwrite(self.filename,self.tmp)
		print('Image saved as:',self.filename)
	
	
	def retranslateUi(self, MainWindow):
		_translate = QtCore.QCoreApplication.translate
		MainWindow.setWindowTitle(_translate("MainWindow", "PyShine video process"))
		self.pushButton_2.setText(_translate("MainWindow", "Start"))
		self.label_2.setText(_translate("MainWindow", "Brightness"))
		self.label_3.setText(_translate("MainWindow", "Blur"))
		self.pushButton.setText(_translate("MainWindow", "Take picture"))

# Subscribe to PyShine Youtube channel for more detail! 

# WEBSITE: www.pyshine.com


if __name__ == "__main__":
	import sys
	app = QtWidgets.QApplication(sys.argv)
	MainWindow = QtWidgets.QMainWindow()
	ui = Ui_MainWindow()
	ui.setupUi(MainWindow)
	MainWindow.show()
	sys.exit(app.exec_())



You may also like the following extension of the above GUI: