I have currently written an python script that takes input from the user's video camera with the following code:
import numpy as np
import cv2
import cv
import datetime
import math
import time
import os
cap = cv2.VideoCapture(0)
def init():
ret, imgBase = cap.read()
print(type(imgBase))`
The above code is completely functional and it does get input from the user. However, instead of getting input from the user's web cam, I want to get input from user's screen. I need something like cap = cv2.ScreenCapture(0) I understand that that doesn't work, but I need something that does a similar function so I can read and capture an image from the user screen. In essence, I need to get a screenshot of the monitor/user's screen.
Only works on Mac:
import os
os.system('screencapture out.jpg')
You can read the screenshot into memory using default python functions.
For further info type man screencapture in a terminal or check this link: https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/screencapture.1.html.
Related
I'm using pyautogui to take few screenshots per second and save them.
pyautogui save the screenshot without the cursor, can I take the screenshot with it by default (without edit the photo)?
This is the code I'm using:
import time
import pyautogui
def takeScreenshot(count):
myScreenshot = pyautogui.screenshot()
myScreenshot.save(r'imgs\screenshot_'+str(count)+'.png')
time.sleep(0.2)
takeScreenshot(count+1)
takeScreenshot(0)
I have a Python Script, which has to import very large image-files (.tiff, ca. 3GB).
Is there a way to display a progressbar in the command line?
I haven't found a way to measure the progress of an import except for text files.
My current function looks like this:
from skimage import io
def import_tiff(filename):
im = io.imread(filename)
return im
Thank you very much!
I check other question on google or stackoverflow, they are talking about run cv2.imshow in script, but my code run in jupyter notebook.
Here is my configuration:
ubuntu 16.4x64
python 3.5
opencv 3.1.0
I start a jupyter notebook: here is the code I put it notebook:
%pylab notebook
import cv2
cvim2disp = cv2.imread('data/home.jpg')
cv2.imshow('HelloWorld', cvim2disp)
cv2.waitKey() #image will not show until this is called
cv2.destroyWindow('HelloWorld') #make sure window closes cleanly
When I execute these code. image will show in a pop up window, but I can not close this window by clicking the x on the top right corner, and a moment later, system will prompt me that the window is not responding, it will give me 2 choices: "wait" , "fore quit". if I hit wait, then It will show the same prompt later, If I hit 'fore quit', then the jupyter notebook kernel die and I have to start over.
I google around, many solution suggest that I should add this code
cv2.startWindowThread()
before imshow, but situation get worse, the kernel hang forever!.
anybody have some idea what's going on.
Here is the pic of my error:
%matplotlib inline
#The line above is necesary to show Matplotlib's plots inside a Jupyter Notebook
import cv2
from matplotlib import pyplot as plt
#Import image
image = cv2.imread("input_path")
#Show the image with matplotlib
plt.imshow(image)
plt.show()
I was having a similar problem, and could not come to a good solution with cv2.imshow() in the Jupyter Notebook. I followed this stackoverflow answer, just using matplotlib to display the image.
import matplotlib.pyplot as plt
# load image using cv2....and do processing.
plt.imshow(cv2.cvtColor(image, cv2.COLOR_BGR2RGB))
# as opencv loads in BGR format by default, we want to show it in RGB.
plt.show()
The API documentation for cv2.waitKey() notes the following:
This function is the only method in HighGUI that can fetch and handle events, so it needs to be called periodically for normal event processing unless HighGUI is used within an environment that takes care of event processing.
So perhaps calling the function in an endless loop would make the window responsive? I haven't tested this, but maybe you would like to try the following:
import cv2
cvim2disp = cv2.imread('data/home.jpg')
cv2.imshow('img', cvim2disp)
while(True):
k = cv2.waitKey(33)
if k == -1: # if no key was pressed, -1 is returned
continue
else:
break
cv2.destroyWindow('img')
This will help you understand what is happening:
import cv2
cvim2disp = cv2.imread('data/home.jpg')
cv2.imshow('HelloWorld', cvim2disp)
cv2.waitKey(0)
cv2.destroyWindow('HelloWorld')
waitKey(0) method is waiting for an input infinitely. When you see a frame of the corresponding image, do not try to close the image using close in top right corner.
Instead press some key. waitkey method will take that as an input and it will return back a value. Further you can also check which key was pressed to close the frame.
Additionally waitKey(33) will keep the frame active for 33 ms and then close it automatically.
destroyWindow() will destroy the current frame if there.
destroyAllWindows() will destroy all the frames currently present.
This will solve.
if your facing problem in google collab ,you can use this patch
from google.colab.patches import cv2_imshow
cv2_imshow(img)
%matplotlib inline
from matplotlib import pyplot as plt
img = cv2.imread(valid_img_paths[1])
plt.imshow(cv2.cvtColor(img, cv2.COLOR_BGR2RGB))
plt.show()
The following code works fine in Jupyter to show one image
%matplotlib inline
import cv2
from matplotlib import pyplot as plt
cap = cv2.VideoCapture(videoFName)
ret, image = cap.read()
image=cv2.resize(image,None,fx=0.25,fy=0.25,interpolation=cv2.INTER_AREA)
plt.imshow(image)
plt.show()
If you want to show the video instead of an image in a separate window, use the following code:
import cv2
cap = cv2.VideoCapture(videoFName)
while cap.isOpened():
ret, image = cap.read()
image=cv2.resize(image,None,fx=0.25,fy=0.25,interpolation=cv2.INTER_AREA)
cv2.imshow('image',image)
k = cv2.waitKey(30) & 0xff # press ESC to exit
if k == 27 or cv2.getWindowProperty('image', 0)<0:
break
cv2.destroyAllWindows()
cap.release()
Make sure the window name match, otherwise it will not work. In this case I use 'image' as window name.
The new window that opens up from Jupyter uses the same kernel as notebook. Just add this below to the code and it would work fine.
cv2.waitKey(0)
cv2.destroyAllWindows()
image = cv2.imread(file_path)
while True:
# Press 'q' for exit
exit_key = ord('q')
if cv2.waitKey(exit_key) & 255 == exit_key:
cv2.destroyAllWindows()
break
cv2.imshow('Image_title', image)
I have just developed a library that is exactly similar to cv2.imshow and it can be used in both Jupyter and colab. It can update the window. Therefore you can easily see the video inside it. It uses HTML canvas and is browser friendly :)
Installation:
pip install opencv_jupyter_ui
Usage:
This is the replacement of cv2.imshow for Jupiter. you need only to replace cv2.imshow with jcv2.imshow. It will work in Jupiter.
First:
please import the library
import opencv_jupyter_ui as jcv2
Then:
change cv2.imshow ->jcv2.imshow
More details exist on the Github Repository. Binder Demo gif
It also supports jcv2.waitKey(100) and jcv2.destroyAllWindows(). In case of the absence of Jupyter, it fallbacks to original cv2 functionality.
In order to change the default keys you can use jcv2.setKeys(['a','b','esc']). Please follow the document for more information
I am not sure if you can open a window from Jupyter Notebook.
cv2.imshow expects a waitKey which doesn't work in Jupyter.
Here is what I have done (using OpenCV 3.3):
from IPython.display import display, HTML
import cv2
import base64
def imshow(name, imageArray):
_, png = cv2.imencode('.png', imageArray)
encoded = base64.b64encode(png)
return HTML(data='''<img alt="{0}" src="data:image/png;base64, {1}"/>'''.format(name, encoded.decode('ascii')))
img = cv2.imread('./media/baboon.jpg',cv2.IMREAD_COLOR)
imshow('baboon', img)
If you don't need to use cv2, just:
from IPython.display import Image
Image('./media/baboon.jpg')
Is there a way to use and plot with opencv2 with ipython notebook?
I am fairly new to python image analysis. I decided to go with the notebook work flow to make nice record as I process and it has been working out quite well using matplotlib/pylab to plot things.
An initial hurdle I had was how to plot things within the notebook. Easy, just use magic:
%matplotlib inline
Later, I wanted to perform manipulations with interactive plots but plotting in a dedicated window would always freeze. Fine, I learnt again that you need to use magic. Instead of just importing the modules:
%pylab
Now I have moved onto working with opencv. I am now back to the same problem, where I either want to plot inline or use dedicated, interactive windows depending on the task at hand. Is there similar magic to use? Is there another way to get things working? Or am I stuck and need to just go back to running a program from IDLE?
As a side note: I know that opencv has installed correctly. Firstly, because I got no errors either installing or importing the cv2 module. Secondly, because I can read in images with cv2 and then plot them with something else.
This is my empty template:
import cv2
import matplotlib.pyplot as plt
import numpy as np
import sys
%matplotlib inline
im = cv2.imread('IMG_FILENAME',0)
h,w = im.shape[:2]
print(im.shape)
plt.imshow(im,cmap='gray')
plt.show()
See online sample
For a Jupyter notebook running on Python 3.5 I had to modify this to:
import io
import cv2
import numpy as np
from IPython.display import clear_output, Image, display
import PIL.Image
def showarray(a, fmt='jpeg'):
a = np.uint8(np.clip(a, 0, 255))
f = io.BytesIO()
PIL.Image.fromarray(a).save(f, fmt)
display(Image(data=f.getvalue()))
There is also that little function that was used into the Google Deepdream Notebook:
import cv2
import numpy as np
from IPython.display import clear_output, Image, display
from cStringIO import StringIO
import PIL.Image
def showarray(a, fmt='jpeg'):
a = np.uint8(np.clip(a, 0, 255))
f = StringIO()
PIL.Image.fromarray(a).save(f, fmt)
display(Image(data=f.getvalue()))
Then you can do :
img = cv2.imread("an_image.jpg")
And simply :
showarray(img)
Each time you need to render the image in a cell
What imaging modules for python will allow you to take a specific size screenshot (not whole screen)?
I have tried PIL, but can't seem to make ImageGrab.grab() select a small rectangle
and i have tried PyGame but i can't make it take a screen shot outside of it's main display panel
You can use pyscreenshot module.
The pyscreenshot module can be used to copy the contents of the screen to a PIL image memory or file.
You can install it using pip.
$ sudo pip install pyscreenshot
Usage:
import pyscreenshot as ImageGrab
# fullscreen
im=ImageGrab.grab()
im.show()
# part of the screen
im=ImageGrab.grab(bbox=(10,10,500,500))
im.show()
# to file
ImageGrab.grab_to_file('im.png')
I have tried PIL, but can't seem to make ImageGrab.grab() select a small rectangle
What did you try?
As the documentation for ImageGrab clearly states, the function has a bbox parameter, and:
The pixels inside the bounding box are returned as an “RGB” image. If the bounding box is omitted, the entire screen is copied.
So, you only get the whole screen if you don't pass a bbox.
Note that, although I linked to the Pillow docs (and you should be using Pillow), old-school PIL's docs say the same thing:
The bounding box argument can be used to copy only a part of the screen.
So, unless you're using a really, really old version of PIL (before 1.1.3, which I believe is more than a decade out of date), it has this feature.
1) Use pyscreenshot, ImageGrab works but only on Windows
2) Grab the image and box it, then save that image
3) Don't use ImageGrab.grab_to_file, it saves the full size image
4) You don't need to show the image with im.show if you just want to save a screenshot
import pyscreenshot as ImageGrab
im=ImageGrab.grab(bbox=(10,10,500,500))
im.save('im.png')
You could use Python MSS.
From documentation to capture only a part of the screen:
import mss
import mss.tools
with mss.mss() as sct:
# The screen part to capture
monitor = {"top": 160, "left": 160, "width": 160, "height": 135}
output = "sct-{top}x{left}_{width}x{height}.png".format(**monitor)
# Grab the data
sct_img = sct.grab(monitor)
# Save to the picture file
mss.tools.to_png(sct_img.rgb, sct_img.size, output=output)
print(output)
You can use pyscreenshot at linux or windows platforms . I am using Ubuntu it works for me. You can force if subprocess is applied setting it to false together with mss gives the best performance.
import pyscreenshot as ImageGrab
import time
t1 = time.time()
imgScreen = ImageGrab.grab(backend="mss", childprocess=False)
img = imgScreen.resize((640,480))
img.save("screen.png")
t2 = time.time()
print("The passing time",(t2-t1))