Take a screenshot via a Python script on Linux
I want to take a screenshot via a python script and unobtrusively save it.
I'm only interested in the Linux solution, and should support any X based environment.
This works without having to use scrot or ImageMagick.
import gtk.gdk
w = gtk.gdk.get_default_root_window()
sz = w.get_size()
print "The size of the window is %d x %d" % sz
pb = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB,False,8,sz[0],sz[1])
pb = pb.get_from_drawable(w,w.get_colormap(),0,0,0,0,sz[0],sz[1])
if (pb != None):
pb.save("screenshot.png","png")
print "Screenshot saved to screenshot.png."
else:
print "Unable to get the screenshot."
Borrowed from http://ubuntuforums.org/showpost.php?p=2681009&postcount=5
Just for completeness: Xlib - But it's somewhat slow when capturing the whole screen:
from Xlib import display, X
import Image #PIL
W,H = 200,200
dsp = display.Display()
try:
root = dsp.screen().root
raw = root.get_image(0, 0, W,H, X.ZPixmap, 0xffffffff)
image = Image.fromstring("RGB", (W, H), raw.data, "raw", "BGRX")
image.show()
finally:
dsp.close()
One could try to trow some types in the bottleneck-files in PyXlib, and then compile it using Cython. That could increase the speed a bit.
Edit: We can write the core of the function in C, and then use it in python from ctypes, here is something I hacked together:
#include <stdio.h>
#include <X11/X.h>
#include <X11/Xlib.h>
//Compile hint: gcc -shared -O3 -lX11 -fPIC -Wl,-soname,prtscn -o prtscn.so prtscn.c
void getScreen(const int, const int, const int, const int, unsigned char *);
void getScreen(const int xx,const int yy,const int W, const int H, /*out*/ unsigned char * data)
{
Display *display = XOpenDisplay(NULL);
Window root = DefaultRootWindow(display);
XImage *image = XGetImage(display,root, xx,yy, W,H, AllPlanes, ZPixmap);
unsigned long red_mask = image->red_mask;
unsigned long green_mask = image->green_mask;
unsigned long blue_mask = image->blue_mask;
int x, y;
int ii = 0;
for (y = 0; y < H; y++) {
for (x = 0; x < W; x++) {
unsigned long pixel = XGetPixel(image,x,y);
unsigned char blue = (pixel & blue_mask);
unsigned char green = (pixel & green_mask) >> 8;
unsigned char red = (pixel & red_mask) >> 16;
data[ii + 2] = blue;
data[ii + 1] = green;
data[ii + 0] = red;
ii += 3;
}
}
XDestroyImage(image);
XDestroyWindow(display, root);
XCloseDisplay(display);
}
And then the python-file:
import ctypes
import os
from PIL import Image
LibName = 'prtscn.so'
AbsLibPath = os.path.dirname(os.path.abspath(__file__)) + os.path.sep + LibName
grab = ctypes.CDLL(AbsLibPath)
def grab_screen(x1,y1,x2,y2):
w, h = x2-x1, y2-y1
size = w * h
objlength = size * 3
grab.getScreen.argtypes = []
result = (ctypes.c_ubyte*objlength)()
grab.getScreen(x1,y1, w, h, result)
return Image.frombuffer('RGB', (w, h), result, 'raw', 'RGB', 0, 1)
if __name__ == '__main__':
im = grab_screen(0,0,1440,900)
im.show()