Screen Capture 3
Procedure
for capturing a single, multiple, and portions of a screen
Document Version: 3.0 (January 23, 2006) 2.0
(03072005); 1.0 (09132004)
Keywords: Single and multiple screen
capture, Portions of screen, Screen Dump, Print Screen, X windows dump, xwd,
xwud, gimp, Paint Shop Pro, Image Magick, import, Adxv, XdisplayF, snapshot,
and ksnapshot.
Introduction
This note describes several procedures for capturing a single and/or multiple screen shots as well as portions of a computer screen (a procedure referred to as screen capture, or screen dump). Screen capture is a quick way to make pictures of your work that can be used for informal presentation or for research discussions. Please note that in general the quality of picture generated using this technique is NOT high enough for publications or for quantitative work. This note is intended for the users of IMB X-Ray Crystallography Facility. This Note is Version 3 in this series about Screen Capture and I have included a procedure for taking a snapshot of a portion of an image rather than the whole window (similar to crop).
List of Programs
The following is the list of programs that can be used to capture the screen:
ii. Windows Utility
ii. gimp
iv. import (ImageMagick): whole window
v. import(ImageMagick): window portion
i. Adxv
ii. XdisplayF
iii. Paint Shop Pro 5.0 (Including Multiple captures)
Operating System Utilities
The operating system utilities are the simplest to use but may not produce the best images. Here we look at both the Linux/UNIX native utility ‘xwd/xwud’ and Window’s ‘PrintScreen’.
Linux’s native utility ‘xwd/xwud’
Most Linux and UNIX operating systems have native utilities called xwd (x-window dump) and xwud (x-window un-dump) that allow the user to capture either the whole screen or a specific window. In order for the user to capture specific window, issue the following command,
soma@raccoon> xwd >myimage.xwd
and then click with the mouse inside the window of choice (if the whole screen needs to captured, simply click anywhere in the screen). The utility will write out an image in the special ‘.xwd’ format. The created image can be viewed either using the related utility ‘xwud’ or using any number of image processing software like, display, gimp, or xv. To view using ‘xwud’ issue the following command,
soma@raccoon> xwud
-in myimage.xwd
The image can be converted to .jpg or .png using the convert utility.
soma@raccoon> convert
myimage.xwd myimage.jpg
MS Window’s native utility ‘PrintScreen’
Similar to Linux’s xwd utility MS Windows has a keyboard combination that will capture the image of the whole screen or a specific window. If you need to capture image of the whole screen simply press “PrintScreen” on your keyboard, open a document or a paint program and paste the captured image. If you need to capture image of a specific window, first select that window with the mouse then press “ALT” and “PrintScreen” keys together. Now paste image into a document or to a paint program for further work.
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To capture image of the whole screen, press ‘PrintScreen’ key and paste the image to a document or a paint program. |
To capture image of a selected window, select the window with mouse, press ‘Alt’ and ‘PrintScreen’ keys together and paste the image to a document. |
Image Processing Programs (Linux/UNIX)
Ksnapshot (snapshot)
Snapshot or (ksnapshot) is an image utility found in many versions of Linux that can be used to capture the entire screen or a specific window. Users can launch the program by issuing the command “ksnapshot” (or equivalent).
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1)
In command line mode: >ksnapshot Or 2)
From “Start Menu” > “KDE Menus” > “Graphics” > “KSnapshot” |
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Now,
1) Input a value of 2 or 3 seconds in “Delay” box, 2) Select a name for
saving the image, here it is snapshot1.png,
and 3) Select “Only grab … pointer” radio button if you need a specific
window, otherwise leave it unselected.
When you are ready capture an image click “Grab” button and point your
mouse cursor to the window of choice.
After 3 seconds delay the image will be captured. Now click “Save” it save the image. |
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The
result will look like the image on the right |
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gimp
Gimp (GNU image manipulation program) is another image manipulation utility found in many versions of Linux that can be used to capture the entire screen or a specific window. The procedure is very similar to that for ksnapshot. The user launches “gimp” from a command line mode which starts the program
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1)
In command line mode: >gimp |
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Select
“File” > “Acquire” > “Screenshot” to open next window |
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Select
1) “Single Window” or “Whole Window” radio button depending on whether you
need to capture full screen or one window, and 2) “With Decorations” to get
image with a border, and 3) input 2 or 3 seconds delay. Press “OK” button and place the cursor on
the image you need. After 2 seconds
delay the captured image will be displayed.
Right click inside the image, select “File” > “Save” menu to save
the image. |
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The
result will look the image on the right.
Note this image acquired with
“No Decorations”. |
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Display (ImageMagick)
Display or Image Magick is another versatile image manipulation utility found in many versions of Linux/UNIX that can be used to capture the entire screen or a specific window. The procedure is very similar to that for gimp.
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In command line mode: > display |
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This
opens Image Magick display program |
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Right
click to get Commands menu. In
Commands menu select “File” > “Open” menu.
In Browse and Select menu select “Grab”. In “Delay Dialog” menu input 2 seconds. |
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Next hit the “Grab” button and point the cursor to the specific window. After 2 seconds delay that window will be captured and displayed. Left click select “Save” and save the image in desired format. |
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The
final image will look like one shown on right |
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Import (ImageMagick): Full Window
Import is another versatile image manipulation utility (part of Image Magick) found in many versions of Linux/UNIX that can be used to capture single or multiple screen shots (as a function of time). The best way to use import utility, however, is from the command line interface.
Let us say you want to capture four (4) images of a window at five (5) second intervals spanning a total duration of twenty (20) seconds. Since we are capturing images as a function of time we can not and should not use mouse click or cursor point to capture the image as that is not practical and is prone to error. So first we need some basic information about the window (xwininfo) we are capturing and second we need to position that window on top of all other windows to avoid overlap. Once all the information is available we can issue the command “import” with specific arguments. First issue xwininfo command and click the mouse on the window you are planning to capture to get the following output.
soma@neptune[11:36am]~>xwininfo | User input
xwininfo: Please select the window about which you would like information by clicking the mouse in that window.