I am currently working with SimpleCV for some image processing. Basically my goal is to have my application take a picture from a simple command in Python, i.e. 'GetPicture()'.
In SimpleCV, it is very easy to get an image from the camera, by using
cam = Camera()
img = cam.getImage()
My problem is that the first line actually shows the camera stream on the screen, and this I don't want. I would like to be able to get the image while displaying something else on the screen, thus taking the picture in 'blind mode'. Possible ?
Any help is much appreciated.
Julien
For those interested...
Eventually I used Pygame in combination with v4l (video for linux) driver. The v4l driver has a no-preview option, which once set, enables one to take a picture in 'blind' mode.
Julien
Related
Environment:
win10 PC notbook
python 3.9
PyQt5==5.15.4 pywin32==304 opencv-python==4.5.5.64 Pillow==9.1.0
Question:
I am trying to grab my whole screen by python. The function is easy, but I get a strange question.
The screenshot image is always blurry and unsharp.
screenshot by windows10 self: windows10 self (PNG)
screenshot by my codes: my codes (PNG)
My Codes as follows:
import cv2
import os
from PIL import ImageGrab
import numpy as np
if os.path.exists('xx.jpg'):
os.remove('xx.jpg')
captureImage = ImageGrab.grab()
width,height = captureImage.size
img = cv2.cvtColor(np.asarray(captureImage), cv2.COLOR_RGB2BGR)
cv2.imwrite('./xx.jpg',img)
cv2.waitKey(0)
I have try alternative method to achieve screenshot function, just like pyqt5/mss/pywin32/pyautogui, but every method leads to the same question.
And I google lots of articles, I found that my screen has scaled to 125%(as recommended), as follow:
PNG:
So I revise it to 100%, the screenshot is sharp. But 125% is normal and comfortable vision.
Then I doubt if it's DPI. But I try these codes, it does not work.
from ctypes import windll
user32 = windll.user32
user32.SetProcessDPIAware()
I am so crazy and curious that how those screenshot software resolve it. After all, we can not ensure every user has the 100% scale and has normal dpi.
I will be grateful if u could give me solutions or advices.
Solution:
Thanks to Christoph Rackwitz.
I had grab a PNG screen and update it and the two PNG image still same. But it's really different in my PC before upload.
I test a lot and I found that I open my codes screenshot by iQIYI Player. But I open windows10 self screenshot by windows Player.
It's the Reason!!!My codes is right and everything is right except iQIYI Player Software. Maybe it's the software bug.
Thanks again.
I have an extremely simple application for a Raspberry Pi. (It's an educational kiosk for a children's museum if anyone cares.) In python, I have an infinite loop in a thread reading a line from a serial port. Based on the input, I display one of 14 different jpg images. I am not putting all the code here, but it's a very bare-bones GDK application. I have an Arduino feeding the serial port the information to cycle through all the images for debug purposes. In response to the input, I do the following:
self.CurrentImage.set_from_file("image.jpg") # the name here is one of 14
Not to anyone's great surprise, this works. But as I let the Arduino hammer at the input, the screen would randomly show a white image and nothing again after. I checked the standard out window and the data was still coming and the images still being read. And when I say random I mean that at some point in the input-and-display process, it stops displaying. There are no errors being reported. Sometimes I might get 4-5 images in sequence before it dies, or I might make it through the list twice. It's simply not deterministic. My mind wandered to thinking maybe I'm not clearing first and having a memory leak. I made the following amendment:
self.CurrentImage.clear()
self.CurrentImage.set_from_file("image.jpg")
The problem persisted. I decided to scrap the method and go for something that didn't involve reloading images. At startup I created a separate GTK Image widget for each file. Then in response to the input data, I did this:
self.CurrentImage.hide()
self.CurrentImage = self.AlphaImage # or one of the other 13 Images I created
self.CurrentImage.show()
The nice thing about this method is that the image displays much faster. The first method had the screen briefly go white as the image was loaded. However, once again, after a random number of image switches, the window goes white. Diagnostic output shows that the loop is happily reading data and selecting images.
In the original version where I loaded images as needed, there was exactly one widget on the window. So it's not possible that another widget is covering it. The second version has an Image widget for each jpg file. If one is covering another, I should still at least see that image.
I'm good at thinking outside the box, but I admit that Linux is a weak area for me. Nothing is occurring to me to try to make this work. I'd whinge that I'm under time pressure here and children will be disappointed... but it was supposed to be done before Christmas and I only got the final art yesterday. That reminds me that there's one final note and the reason I thought my first method was failing: I created temporary graphics of my own that was one word of black text on a white background. Those images displayed without problem until the screensaver kicked in.
I'm open to any suggestion as to how to track this down and fix it.
Thanks to Sylvester, I figured this one out. The problem isn't how I was updating the images, it was where I was doing it. In the thread catching the serial input was not the place to do it. I reduced the thread to simply reading the line, then did the following:
GLib.idle_add( self.updateImage, lineInput )
then in the function updateImage I did the business logic of selecting the correct image and updating. Problem solved.
Is there any way of embedding a video player into the GUI of a python program and then displaying video from a piCamera to it in real time?
Currently, when I preview it fills the whole screen and makes any GUI unusable.
I would like to overlay information over the video capture.
I'm not too hot on Python but on Visual Studio for example you could use the VLC plug-in and use it as a display component.
There's lots of tutorials about how to host video and stream it to a server but nothing covers local display.
Cheers.
I'm not sure if this is exactly what you are looking for, but I use RPi-Cam-Web-Interface. If you are not aware of it you may want to take a look: http://elinux.org/RPi-Cam-Web-Interface
I am trying to understand how I can use PIL in Python 2.7 to search the whole screen for a certain image and click on it. I've been searching around and haven't been able to find a solution. I want to create a small GUI with one button in the middle of it that when clicked will search the entire screen for a predefined image. Once the image is found the program will then click in the centre of it and end. In short the program will detect if an image is present on the users screen and click it.
I did find an interesting bit on Sikuli, but that doesn't help me because it's unable to export to an .exe.
The image that the program will look for will most likely be in the same place each time it searches, but I didn't want to hard-code the location as it has the potential to move and I don't want that being an issue later on.
What I need is the code method I would use to search for the image on screen and send back the cords to a variable.
Image explanation/example:
Reference image of rifle:
PIL is the wrong tool for this job. Instead you should look into openCV (open source computer vision), which has fantastic python bindings. Here is a link to an example (in C but should be easy to redo with the python bindings) that does what you are looking for, but even allows the image to be rotated, scaled, etc.
http://docs.opencv.org/doc/tutorials/features2d/feature_homography/feature_homography.html
http://docs.opencv.org/doc/tutorials/features2d/detection_of_planar_objects/detection_of_planar_objects.html
Edit:
I assume you are using windows, as your example image looks like window. In this case you can use:
from PIL import ImageGrab
pil_img = ImageGrab.grab()
opencv_img = numpy.array(pil_img)
then use opencv to process the image to find sub image you are looking for.
If you want to do this cross platform, then you will need to use wxWidgets to do the screengrab: https://stackoverflow.com/a/10089645/455532
Even I wanted to do the same but using different module - pyautogui. I finally found the solution for my problem and I am sure this solution will also help you.
You have to just go to this webpage and read the locate function topic completely
and you'll be able to solve your problem.
I recommend you give a look on PyAutoGUI, a well documented library to control mouse and keyboard, also can locate imagens on screen, find the position, move the mouse to any location and clicks on location, also can simulate drag and drop, type on input fields, give double clicks and much more.
I am using the Pygame module in python to take pictures with my webcam. The problem is that I would like to export a video file (don't care what type) to use elsewhere. Since pygame cannot export video directly, I guess that there is two ways to do it:
Somehow stitch the photos Pygame creates into a video. (my preferred method)
Use an external library.
I only need 4 frames per second, and I don't care about the picture quality.
How can I make a video with python / pygame?
I have the same problem and am searching the solution.
I found this
This seems work well though I didn't try yet.
Hope this helps.