CREATING A SNAPSHOT
Transana offers a number of ways of bringing still images into the data analysis process. We have already discussed adding an image to a Document or Transcript as a mechanism for situating a still image in text data or in a media file’s Transcript.
You can also create free-standing codable images, called Snapshots, for analysis in Transana. These images may be independent, or they may be linked to a media file. They may be loaded from still image files or can be captured from video within Transana.
Create and Code A Snapshot From A Graphics File
Right-click a Collection where you would like to place a Snapshot. Choose Add Snapshot from the popup menu.
To load an image from a graphic file, press the Browse button and browse to the directory where you stored the image you would like to import and select the file. Press Open to confirm the file selection. Notice that if you have not entered a Snapshot ID, Transana will name the Snapshot after the file name.
If you want to associate this graphic file with a particular spot in a particular Episode, select the appropriate Library ID, Episode ID, and Transcript ID, then enter the Episode Position and Duration for the Snapshot. You should be able to determine these values by looking at the Visualization Window’s Current Time indicator while working with your Episode. If you do this, the Snapshot’s coding will be reported as part of the Episode’s coding in appropriate Reports, Maps, and Graphs.
We also may add some Keywords on this form. Keywords added here are coded for the entire image. Then press OK to indicate you are done defining the Snapshot Properties.
Transana now displays the Snapshot in the Snapshot Window, ready for detailed coding. Press the Edit / Read-only Mode button to place the Snapshot into Edit mode so that your upcoming changes will be retained.
The first thing to do is to frame the image properly. Use a combination of zooming, positioning the image in the frame, and resizing the Snapshot Window to get the image to look exactly the way you want. We want to reduce the amount of white space around the image in our example, but you may want to focus on a particular portion of your image.
(Credit: Images copyright Digital Globe www.digitalglobe.com)
Our sample image contains two satellite views of Biloxi, Mississippi, one taken before Hurricane Katrina and one taken two days after the hurricane made landfall. We will use Detailed Image Coding to highlight some of our observations about these photos.
In this example, I’ve drawn green and blue dashed ovals around buildings that appear in both photos, orange dotted lines about neighborhoods of desctruction and debris, and pink and red solid rectangles around two casinos clearly destroyed by the storm. As you can see, each Keyword gets its own color, shape, line style, and line thickness. The Coding Key shows you what keyword each combination of drawing features represents.
If you can’t draw a coding shape on your image, check to make sure you’re in Edit Mode and have selected a Keyword. If you don’t get the line positioned exactly like you want it on your first try, you can always right-click the coding shape and select Delete from the popup menu, then try again. Note that you can draw as many coding shapes on a Snapshot as you wish. It’s best if each Keyword has a unique combination of color, shape, line thickness, and line style.
Leave Edit Mode to save the sizing, positioning, and coding you’ve done on the Snapshot.
When you are in Exploration Mode (i.e. when you are NOT in Edit Mode), you can explore your coded Snapshot, including hiding and showing different codes, resizing the image or frame, and so on, without affecting the saved settings of the Snapshot. Changes are only saved when you are in Edit Mode.
Create A Snapshot By Capturing A Video Screen Shot
You can also create a Snapshot by capturing a frame from a video file within Transana. Start by loading an Episode Transcript with an associated video file. Play the video until you come across in interesting visual and pause the video there.
Now right-click a Collection where you would like to place the Snapshot. Choose Add Snapshot from the popup menu.
We want to capture a screen shot from the currently loaded and positioned video, so press the Capture Snapshot for Coding button next to the “Browse” button on the Add Snapshot dialog box. This will call up Transana’s Media File Conversion tool.
When you capture a screen shot to be placed in a Document or Transcript, you do not have to worry about the file name given to that screen shot. That’s because images are actually imported into a Document or Transcript and immediately lose their connection with the source image file. Snapshots, on the other hand, maintain a connection to the source file, much the same way that Transana’s Episodes and Clips maintain a connection to the media file(s) they are connected to.
As a result, you need to change the Destination Media File name on the Media File Conversion form. This greatly reduces the chances of accidentally over-writing your Snapshot image with a different screen shot from the same media file. Change the file name from the default name to something unique and identifiable. (Transana will automatically append the necessary “_%06d” text to the end of the file name.) Press “Convert”.
Edit the Snapshot ID if desired. Notice that this Snapshot is automatically connected to the current video position in the Episode from which it was captured. However, you may wish to adjust the Episode Position to and the duration to more accurately reflect the time that the image appears in the video. Finally, you may wish to add some Keywords as Whole Snapshot Keywords. Press “OK”.
You will now see the Snapshot Window, as described in our first example. Go into Edit mode so you can frame and code the image as you wish.
Press the “Show Coding Key” button in the Snapshot Window so the Coding Key is displayed. You will note that the coding key helps connect the color, shape, style and line thickness of the Coding Shapes to your Keywords.
Our Analyzing Still Images with Transana ScreenCast takes you step by step through importing, creating, coding and analyzing images in Transana (12:43, Transana 2.60 shown).
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