Prerequisite: Introduction to pyqt-5
PyQt5 is a cross-platform GUI toolkit, a set of python bindings for Qt v5. One can develop an interactive desktop application with so much ease because of the tools and simplicity provided by this library.
In this article, we will see how we can create a simple camera application using PyQt5, which will capture the images and save them in the desired location which can be changed any time.
GUI Implementation Steps :
- Create the main window.
- Add QCameraViewfinder object as the central widget to the main window.
- Add a status bar to the window for status tips.
- Add the toolbar to the window.
- Add Click and change location actions to the toolbar, and a combo box for selecting the camera, below is how toolbar will look like.
Back-End Implementation Steps :
- Create a path variable and set it currently to blank.
- Add available cameras to the combo box and set the first camera as default.
- Add action to the Take Photo button.
- Inside the click action, capture the photo at the given path with name as a timestamp and increment the count.
- Add action to the change location button.
- Inside the change location action, open the dialog box to get the path and update the path and the counter.
- Add action to the combo box.
- Inside the combo, box action get the selected camera, set viewfinder to it, and the mode of capture.
- Create an alert method that shows an error message if any error is shown while selecting the path and changing the camera.
Below is the implementation :
Python3
# importing required libraries from PyQt5.QtWidgets import *from PyQt5.QtMultimedia import *from PyQt5.QtMultimediaWidgets import *import os import sys import time # Main window class class MainWindow(QMainWindow): # constructor def __init__(self): super().__init__() # setting geometry self.setGeometry(100, 100, 800, 600) # setting style sheet self.setStyleSheet("background : lightgrey;") # getting available cameras self.available_cameras = QCameraInfo.availableCameras() # if no camera found if not self.available_cameras: # exit the code sys.exit() # creating a status bar self.status = QStatusBar() # setting style sheet to the status bar self.status.setStyleSheet("background : white;") # adding status bar to the main window self.setStatusBar(self.status) # path to save self.save_path = "" # creating a QCameraViewfinder object self.viewfinder = QCameraViewfinder() # showing this viewfinder self.viewfinder.show() # making it central widget of main window self.setCentralWidget(self.viewfinder) # Set the default camera. self.select_camera(0) # creating a tool bar toolbar = QToolBar("Camera Tool Bar") # adding tool bar to main window self.addToolBar(toolbar) # creating a photo action to take photo click_action = QAction("Click photo", self) # adding status tip to the photo action click_action.setStatusTip("This will capture picture") # adding tool tip click_action.setToolTip("Capture picture") # adding action to it # calling take_photo method click_action.triggered.connect(self.click_photo) # adding this to the tool bar toolbar.addAction(click_action) # similarly creating action for changing save folder change_folder_action = QAction("Change save location", self) # adding status tip change_folder_action.setStatusTip("Change folder where picture will be saved saved.") # adding tool tip to it change_folder_action.setToolTip("Change save location") # setting calling method to the change folder action # when triggered signal is emitted change_folder_action.triggered.connect(self.change_folder) # adding this to the tool bar toolbar.addAction(change_folder_action) # creating a combo box for selecting camera camera_selector = QComboBox() # adding status tip to it camera_selector.setStatusTip("Choose camera to take pictures") # adding tool tip to it camera_selector.setToolTip("Select Camera") camera_selector.setToolTipDuration(2500) # adding items to the combo box camera_selector.addItems([camera.description() for camera in self.available_cameras]) # adding action to the combo box # calling the select camera method camera_selector.currentIndexChanged.connect(self.select_camera) # adding this to tool bar toolbar.addWidget(camera_selector) # setting tool bar stylesheet toolbar.setStyleSheet("background : white;") # setting window title self.setWindowTitle("PyQt5 Cam") # showing the main window self.show() # method to select camera def select_camera(self, i): # getting the selected camera self.camera = QCamera(self.available_cameras[i]) # setting view finder to the camera self.camera.setViewfinder(self.viewfinder) # setting capture mode to the camera self.camera.setCaptureMode(QCamera.CaptureStillImage) # if any error occur show the alert self.camera.error.connect(lambda: self.alert(self.camera.errorString())) # start the camera self.camera.start() # creating a QCameraImageCapture object self.capture = QCameraImageCapture(self.camera) # showing alert if error occur self.capture.error.connect(lambda error_msg, error, msg: self.alert(msg)) # when image captured showing message self.capture.imageCaptured.connect(lambda d, i: self.status.showMessage("Image captured : " + str(self.save_seq))) # getting current camera name self.current_camera_name = self.available_cameras[i].description() # initial save sequence self.save_seq = 0 # method to take photo def click_photo(self): # time stamp timestamp = time.strftime("%d-%b-%Y-%H_%M_%S") # capture the image and save it on the save path self.capture.capture(os.path.join(self.save_path, "%s-%04d-%s.jpg" % ( self.current_camera_name, self.save_seq, timestamp ))) # increment the sequence self.save_seq += 1 # change folder method def change_folder(self): # open the dialog to select path path = QFileDialog.getExistingDirectory(self, "Picture Location", "") # if path is selected if path: # update the path self.save_path = path # update the sequence self.save_seq = 0 # method for alerts def alert(self, msg): # error message error = QErrorMessage(self) # setting text to the error message error.showMessage(msg) # Driver code if __name__ == "__main__" : # create pyqt5 app App = QApplication(sys.argv) # create the instance of our Window window = MainWindow() # start the app sys.exit(App.exec()) |
Output :
When we click on the change location, this dialog will appear
Let’s go to this folder and see if the images are captured or not
