CODEWITHSUNDEEP
javaandroideclipsejarimagej
user3507655
user3507655

Reputation: 23

Trouble integrating ImageJ into Android App

I am creating an Android app that can filter photos. To perform the image processing necessary for these filters, I use ImageJ's API. The user selects the filters to apply to a photo collection in a dialog box. Upon pressing "OK," however, the app crashes, and the following output appears in LogCat (I'm using Eclipse):

04-07 15:09:24.094: E/AndroidRuntime(14901): FATAL EXCEPTION: main
04-07 15:09:24.094: E/AndroidRuntime(14901): Process: edu.wpi.khufnagle.lighthousenavigator, PID: 14901
04-07 15:09:24.094: E/AndroidRuntime(14901): java.lang.NoClassDefFoundError: ij.io.Opener
04-07 15:09:24.094: E/AndroidRuntime(14901):    at edu.wpi.khufnagle.lighthousenavigator.filter.ImageManipulator.validateOriginalImage(ImageManipulator.java:38)
04-07 15:09:24.094: E/AndroidRuntime(14901):    at edu.wpi.khufnagle.lighthousenavigator.filter.LighthousePresenceFilter.<init>(LighthousePresenceFilter.java:120)
04-07 15:09:24.094: E/AndroidRuntime(14901):    at edu.wpi.khufnagle.lighthousenavigator.filter.PhotographFilter.filterPhotos(PhotographFilter.java:137)
04-07 15:09:24.094: E/AndroidRuntime(14901):    at edu.wpi.khufnagle.lighthousenavigator.PhotographsActivity$5.onClick(PhotographsActivity.java:623)
04-07 15:09:24.094: E/AndroidRuntime(14901):    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
04-07 15:09:24.094: E/AndroidRuntime(14901):    at android.os.Handler.dispatchMessage(Handler.java:102)

As you might guess, the line in question within the validateOriginalImage() method creates a new Opener object from ImageJ (used for opening the image as an ImagePlus object on the following line for later processing).

This exception occurs when I add the "ij.jar" to my app's build path as an external JAR file (on the "Libraries" tab of Eclipse's "Configure Build Path" dialog) or when I include the entire ImageJ source code as a separate Java project in my workspace on the app's build path (on the "Projects" tab). I am using version 1.48 of the "ij.jar" file or version 1.47v of the source code (never both, as that would obviously cause some conflicts during the build process).

In an attempt to solve this problem, I included the ImageJ source code (1.47v as above) within the "src" directory of the app project itself, and I receive a different but equally fatal exception when I attempted to select something in the filtering dialog within the app:

04-07 15:11:07.530: E/AndroidRuntime(29709): FATAL EXCEPTION: main
04-07 15:11:07.530: E/AndroidRuntime(29709): Process: edu.wpi.khufnagle.lighthousenavigator, PID: 29709
04-07 15:11:07.530: E/AndroidRuntime(29709): java.lang.ExceptionInInitializerError
04-07 15:11:07.530: E/AndroidRuntime(29709):    at ij.Menus.<clinit>(Menus.java:80)
04-07 15:11:07.530: E/AndroidRuntime(29709):    at ij.io.Opener.<clinit>(Opener.java:51)
04-07 15:11:07.530: E/AndroidRuntime(29709):    at edu.wpi.khufnagle.lighthousenavigator.filter.ImageManipulator.validateOriginalImage(ImageManipulator.java:38)
.
.
.
04-07 15:11:07.530: E/AndroidRuntime(29709): Caused by: java.lang.StringIndexOutOfBoundsException: length=1; regionStart=0; regionLength=3
04-07 15:11:07.530: E/AndroidRuntime(29709):    at java.lang.String.startEndAndLength(String.java:588)
04-07 15:11:07.530: E/AndroidRuntime(29709):    at java.lang.String.substring(String.java:1475)
04-07 15:11:07.530: E/AndroidRuntime(29709):    at ij.IJ.<clinit>(IJ.java:65)
04-07 15:11:07.530: E/AndroidRuntime(29709):    ... 15 more

That StringIndexOutOfBoundsException is occurring on a line of code in the IJ.java that checks the version of Java I'm running. Apparently, ImageJ thinks this version string is blank, and when it attempts to take the substring of this (seemingly) blank string, the code throws an exception.

Are there any ImageJ/Eclipse gurus who can help integrate ImageJ into my app successfully?

Upvotes: 2

Views: 1346

Answers (1)

MMendes
MMendes

Reputation: 84

Be aware that in java you get the java version like this:

System.getProperty(“java.version”)

http://deviltechie.wordpress.com/2011/03/16/get-the-version-of-java-runtime/

But in Android its a bit different:

PackageInfo pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
version = pInfo.versionName;

Get application version programmatically in android

That would explain the NoClassDefFoundError.

Upvotes: 1

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