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1 Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, WCC, Room 306, 330 Brookline Ave., Boston, MA 02215.
Received February 10, 2007; accepted after revision June 7, 2007.
Address correspondence to C. S. Yam.
OBJECTIVE. The purpose of this article is to describe an alternative for creating scrollable movie loops for electronic presentations including PowerPoint.
CONCLUSION. The alternative provided in this article enables academic radiologists to present scrollable movie loops in PowerPoint. The scrolling capability is created using Flash ActionScript. A Flash template with the required ActionScript code is provided. Users can simply download the template and follow the step-by-step demonstration to create scrollable movie loops. No previous ActionScript programming knowledge is necessary.
Keywords: ActionScript • electronic presentation • Flash • movie clip • PowerPoint • scrollable movie loop
With recent advancements in computing power and imaging technology (e.g., submillimeter MDCT scanners), many functional and dynamic studies such as cardiac CT angiography that could not be performed easily in the past are now routine protocols in many radiology settings. As a result, more and more dynamic data sets from these types of studies are being presented in today's radiology conferences. The traditional approach for presenting dynamic data sets is the use of a movie clip, such as QuickTime (Apple) and AVI (Microsoft) in Microsoft PowerPoint presentations. Although movie clips are adequate for showing an image sequence as a continuous movie loop, they do not provide user interactivity for controlling the image display (i.e., the image scrolling function).
Previously, in 2002 and 2004, two different methods were proposed for enabling image scrolling in PowerPoint [1, 2]. However, both these methods require the installation of third-party software or PowerPoint components (add-ins or plug-ins) on the presentation computer and therefore may not be compatible with the newly established electronic presentation (e-presentation) format in today's radiologic society meetings such as the American Roentgen Ray Society (ARRS) and the Radiological Society of North America (RSNA). For instance, at the RSNA 2005 and 2006 annual meetings, PowerPoint transitions, animations, and other plug-ins could not be supported by the e-presentation system.
Instead, presenters can use Adobe Flash (.swf) for animations in their e-presentations. Besides the capability of creating animations, Flash can also be used to create PowerPoint-style presentations. For instance, since 2005, presenters at the ARRS annual meetings have had the ability to choose between PowerPoint and Flash as their presentation format [3, 4].
Although Flash is a useful alternative for creating interactive content for e-presentations, it is still unfamiliar to many academic radiologists. To help radiologists explore the potential of this new technology, basic concepts and tutorials for Flash have been provided in two recent articles [5, 6]. In the first article [5], an introduction was provided including basic terminologies, screen tools, and function panels. Essential steps for creating simple PowerPoint-style presentations were also discussed. In the second article [6], step-by-step tutorials for converting common movie clips (e.g., AVI and QuickTime) into Flash movies were shown. Detailed information for embedding Flash movies into PowerPoint was also provided. This current article provides the essential techniques for creating interactive content using Flash ActionScript (i.e., a scrollable movie loop for PowerPoint presentations).
ActionScript is a common programming language used by many Flash developers to create interactive Web-based applications. Depending on the complexity of the application, programming ActionScript can be complicated and may require certain software development skills and experience. However, for a simple scrollable movie loop, the required coding is rather standard. An annotated version of this code is provided in Appendix 1. For demonstration, a Flash template containing this code has been prepared for this article (Fig. S1 in the supplemental data). Users can simply download the template and follow the demonstration to create scrollable movie loops (no coding is required).
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To begin, users must download the supplemental data file from the supplemental data for this article (Fig. S1). This is a self-extracting zipped file created using WinZip 11.1 (Win-Zip.com). Double-click the downloaded file, click "Browse" and select a common location (e.g., desktop) for unzipping the data, and then click "Unzip." A folder "\desktop\Supplemental Data" will be created containing six files and one subfolder: ScrollableCine.fla (Flash template for Flash 8 or Flash 9), ScrollableCine_MX.fla (Flash template for Flash 7), JPEGImages (folder of 50 JPEG images), CT.avi (sample movie clip), CT_1.swf (Flash movie), CT_2.swf (Flash movie), and SWF_Into_PPT.ppt (PowerPoint macro for inserting Flash).
Software Requirements
Although Flash Player is freeware required for viewing Flash movies on Web pages or PowerPoint (i.e., a preinstalled component in many new operating systems for both Mac [Apple] and PC), Flash Professional (or Flash Pro) is a commercial product for creating Flash movies. At the time of this writing, the latest version of Flash Pro is 9 (or Adobe Creative Suite 3/CS3 ($699, $199 upgrade, and $123 academic) [7]. To use the Flash template provided in this article, users will need to have Flash Pro installed on their computers. A 30-day trial of this application is available at the Adobe Website (www.adobe.com/products/flash/). Academic institutions may purchase this application for educational use.
Although Flash 8 Pro and Microsoft Windows XP Pro are used for this article, the essential steps described in the following demonstration can be used in other systems (e.g., Mac OS 10.3.9 and Windows 2000; Flash 7/MX2004 and Flash 9).
Demonstration
Launching the Template
To begin, in the supplemental folder (Fig. S1), double-click on the file
"ScrollableCine.fla" to launch the template
(Fig. 1). Depending on software
settings, the screen layout may be different from the one shown in
Figure 1. Closing all the
panels except for Properties can maximize the workspace. Also, use the
"Fit in Window" option to ensure the entire screen is visible
(Fig. 1).
The template dimensions are preset at 550 x 600 pixels (width x height) with a display rate of 10 frames per second (fps). This setting is most appropriate for presenting movie loops of CT, MR, and sonography images for PowerPoint and e-presentations. However, users can modify this setting at the Properties panel as needed (Fig. 1).
The template contains one screen, two buttons (Play and Stop), and one text box. When the Play button is clicked, the movie loop will advance automatically at the preset frame rate (in this case, 10 fps). If the Stop button is clicked, the movie loop will pause, and users can scroll the images manually (i.e., click and drag the computer mouse in up–down directions). The text box at the top of the screen indicates the current frame (e.g., 1/20, 2/20, etc.). As mentioned, this scrolling function is preprogrammed using ActionScript. For advanced users, the source code can be viewed at the Actions panel (Fig. 1).
The next step is to import the source data. For demonstration, the sample image sequence (i.e., the 50 JPEG images provided in the supplemental data) will be used.
When preparing an image sequence, images must be named sequentially (e.g., CT001.jpg, CT002.jpg, and so on) and placed in a single folder before importing the images. See Table 1 for supported image formats.
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Importing the Source Data
While the Flash template "ScrollableCine.fla" is open, import
the sample image sequence with the following steps. Select "Insert
New Symbol" from the top menu, choose the "Movie
clip" option (Fig. 2A),
and then click "OK." Select "File Import
Import to Stage" from the top menu, navigate the file location to the
sample image folder ("\desktop\Supplemental Data\JPEGImages\"),
click the first image (CT01.jpg), and then click "Open"
(Fig. 2B). Click
"Yes" to accept loading all the images
(Fig. 2C). Immediately, click
the "Scene 1" icon to return to the main screen
(Fig. 2D), and then drag the
"Symbol 1" icon from the Library onto the Screen
(Fig. 2D). (If the Library
panel is closed, select "Window Library" to open it.).
Enter "cine" (lowercase) for the Instance Name at the Properties
panel (Fig. 2E). As an option,
users can position and resize the images as needed
(Fig. 2E). Select "File
Export Export Movie" from the top menu, navigate the file
location to desktop and enter the filename "CT_1.swf," then click
"Save." Select "80%" for JPEG quality, and then click
"OK" to finish (Fig.
3). Press the Ctrl + Enter keys to play the movie, and then press
Ctrl + W keys to end. Select "File Exit" from the top menu
to quit. Click "No" to finish. This will keep the Flash template
unchanged for future use.
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Inserting a Flash Movie into PowerPoint
Unlike movie clips that must be linked to PowerPoint as external data,
Flash movies can be embedded into PowerPoint as part of the presentation file.
Unfortunately, the standard method for importing Flash into PowerPoint as
documented by Microsoft is complicated. To simplify this cumbersome process, a
PowerPoint macro SWF_Into_PPT.ppt has been developed
[8] and is included in the
supplemental material. As mentioned, the macro security must be set to Medium
before running this PowerPoint template (i.e., in PowerPoint, select
"Tools Macro Security" from the top menu, choose
"Medium," and then click "OK").
Use the following steps to insert the sample Flash movie. Double-click the PowerPoint template "SWF_Into_PPT.ppt." Select "Enable Macros." Press the Alt + F8 keys together. Choose "Insert Flash" and click "Run." Select a Flash movie (e.g., CT_1.swf) and click "Open." If the "Enable Macros" option does not show when launching the template, change the security setting to "Medium" as described and restart PowerPoint. More detailed information for using this macro is available in a previous article [8].
Besides using an image sequence, users can also choose movie clips as the source data (Table 1). The process for importing movie clips into Flash has been discussed in a previous article [6]. However, for demonstration, the essential steps for importing a sample movie clip into the Flash template are provided in Appendix 2.
Using Flash Movies in Electronic Presentations
There are two options for using Flash movies in an e-presentation. Flash
movies can be used as standalone presentations without the need of PowerPoint,
or they can be embedded into PowerPoint. Nonetheless, because e-presentation
is still in its emerging period, the presenting mechanism among radiology
societies varies, especially for file uploading. For instance, for RSNA annual
meetings, Flash movies and PowerPoint presentations must be uploaded to the
presentation server separately, whereas the ARRS allows Flash to be uploaded
as either a standalone presentation or within PowerPoint. Users should always
follow the submission guidelines.
Limitations
The alternative provided in this article requires the software application Flash. Although some academic radiologists can obtain this application from their institution, many may need to purchase it at their own expense.
Although users do not need to have programming skills to use the Flash template to create scrollable movie loops, coding in ActionScript may not be an easy task for many academic radiologists. For advanced users, an annotated version of the source code is provided for the development of other Flash applications (Appendix 1). Practical examples and basic programming tutorials on Flash and ActionScript are also available at the official Adobe support Website (www.adobe.com/support/flash/) and many other Internet resources such as www.actionscripts.org/tutorials.shtml and www.en.wikipedia.org/wiki/ActionScript.
Because this article focuses on the use of the Flash template to create scrollable movie loops, it does not provide detailed information for collecting teaching images from PACS. Although some of today's new workstations or PACS viewers enable academic radiologists to export teaching images directly to external media such as a USB drive, some clinical settings may not have this function. However, general mechanisms for exporting teaching images from PACS (either as DI-COM files, JPEG images, or AVI movies) have been discussed previously [9, 10]. Users should refer to these references for more detailed information.
Discussion
The solution provided in the article enables academic radiologists to create Flash movies with image scrolling capability that can be used in today's e-presentation systems, including PowerPoint, at major radiology meetings. Users without ActionScript programming experience can follow the step-by-step instructions with the provided Flash template to create scrollable movie loops.
Although this interactive feature is useful for enhancing presentations and education purposes, it may not be a necessary requirement for some academic radiologists. For presenting simple movie loops in e-presentations (i.e., without this image scrolling feature), the animated GIF is already a compatible and adequate solution. A simple method for converting common movie clips, such as AVI, Quick-Time, and MPEG (Motion Picture Experts' Group) movies, into animated GIFs using Adobe Photoshop has been discussed in a separate article [11].
In addition to e-presentation, Flash movies can also be used in Web pages,
especially for Web-based digital teaching files. Flash has built-in functions
for generating HTML pages specifically for this purpose. Select "File
Publish Settings" to open the Publish Settings window. Under the
"Formats" tab, select both "Flash" and
"HTML" as the output options. Click on the "Publish"
button to generate the Web document. Note: Flash can also be embedded into
other types of digital documents such as PDF (portable document format, Adobe
Acrobat).
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APPENDIX 2: Importing the Sample Movie Clip into the Adobe Flash Template
Unlike an image sequence, which must be imported via a Symbol, movie clips such as Microsoft AVI (audiovideo interleaved) and Apple QuickTime can be imported directly onto the screen. To begin, double-click the file "ScrollableCine.fla" (Fig. S1 in supplemental data) to launch the Flash template. While the template is opened, use the following steps to import the sample movie clip (CT.avi), also provided in the supplemental data.
Select "File Import Import
Video" from the top menu.
Click "Browse," select the movie (CT.avi), click "Open," and then click "Next."
Select "Embed video in SWF and play in timeline," and then click "Next."
Select "Movie clip" and accept the default options, and then click "Next" (Fig. 4A).
Select "Flash 8 – High Quality." In the "Advanced Settings" tab, select the "On2 VP6" codec, "Same as source" frame rate, "Custom" quality, and "7000" kbps data rate. Click "Next," and then click "Finish." See Figure 4B for detailed settings.
------The following steps are the same as the image sequence example-----
Enter "cine" (lowercase) for the Instance Name at the Properties panel (Fig. 2E). As an option, users can position and resize the images as needed (Fig. 2E).
Select "File Export Export
Movie" from the top menu, navigate the file location to desktop and
enter the filename "CT_2.swf," and then click
"Save."
Select "80" for JPEG quality, then click "OK" to finish (Fig. 3).
Press the Ctrl + Enter keys to play the movie, and then Ctrl + W keys to end.
Select "File Exit" from the top menu to
quit. Click "No" to finish.
In this case, the size of this Flash movie loop (i.e., \desktop\CT_2.swf) is 2.31 MB.
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