ludios / Desktopmagic

Robust multi-monitor screenshot grabbing library for Python 2.x/3.x on Windows

Desktopmagic

Desktopmagic takes screenshots on Windows. It supports any arrangement of multiple monitors, and does not leak memory in any failure mode (locked workstation, no monitor attached, etc). If you wish, it can be used continuously to take millions of screenshots.

You may want this instead of PIL's ImageGrab because:

• Desktopmagic can take a screenshot of all monitors. You can:

  • Take a screenshot of the entire virtual screen.

  • Take a screenshot of the entire virtual screen, split into one PIL Image per display.

  • Take a screenshot of just one display.

  • Take a screenshot of an arbitrary region of the virtual screen.

  (See below for usage)

• ImageGrab leaks memory if you try to take a screenshot when the workstation is locked (as of 2011-01).

Requirements

• Python 2.6, 2.7, or 3.3+

• pywin32: http://sourceforge.net/projects/pywin32/files/pywin32/

• PIL or Pillow, unless you don't need getScreenAsImage, getDisplaysAsImages, or getRectAsImage.

  • PIL: http://www.pythonware.com/products/pil/

  • Pillow: https://pypi.python.org/pypi/Pillow/

Installation

pip install --user Desktopmagic

or:

git clone https://github.com/ludios/Desktopmagic
cd Desktopmagic
pip install --user .

or without pip:

python setup.py install --user

This installs the module desktopmagic and the script screengrab_torture_test.

Examples

from __future__ import print_function

from desktopmagic.screengrab_win32 import (
	getDisplayRects, saveScreenToBmp, saveRectToBmp, getScreenAsImage,
	getRectAsImage, getDisplaysAsImages)

# Save the entire virtual screen as a BMP (no PIL required)
saveScreenToBmp('screencapture_entire.bmp')

# Save an arbitrary rectangle of the virtual screen as a BMP (no PIL required)
saveRectToBmp('screencapture_256_256.bmp', rect=(0, 0, 256, 256))

# Save the entire virtual screen as a PNG
entireScreen = getScreenAsImage()
entireScreen.save('screencapture_entire.png', format='png')

# Get bounding rectangles for all displays, in display order
print("Display rects are:", getDisplayRects())
# -> something like [(0, 0, 1280, 1024), (-1280, 0, 0, 1024), (1280, -176, 3200, 1024)]

# Capture an arbitrary rectangle of the virtual screen: (left, top, right, bottom)
rect256 = getRectAsImage((0, 0, 256, 256))
rect256.save('screencapture_256_256.png', format='png')

# Unsynchronized capture, one display at a time.
# If you need all displays, use getDisplaysAsImages() instead.
for displayNumber, rect in enumerate(getDisplayRects(), 1):
	imDisplay = getRectAsImage(rect)
	imDisplay.save('screencapture_unsync_display_%d.png' % (displayNumber,), format='png')

# Synchronized capture, entire virtual screen at once, cropped to one Image per display.
for displayNumber, im in enumerate(getDisplaysAsImages(), 1):
	im.save('screencapture_sync_display_%d.png' % (displayNumber,), format='png')

For more information, see the docstrings in https://github.com/ludios/Desktopmagic/blob/master/desktopmagic/screengrab_win32.py

Known issues

• Screenshots are incorrectly cropped on high-DPI displays. Windows returns display geometry data scaled for the DPI, while the actual screenshots are unscaled. Workaround: Right-click on python.exe, Properties, Compatibility tab, check 'Disable display scaling on high DPI settings'. Repeat for pythonw.exe.