java.lang.UnsatisfiedLinkError when using binaries built from source.

asked 2015-07-19 09:24:12 -0500

smwikipedia gravatar image

updated 2015-07-19 10:06:03 -0500

I just built the opencv-300.jar and opencv_java300.dll from source with extra modules from the opencv contrib repo. I used the jar and dll in my Java project. But it reports the following error when I try to create the BRISK DescriptorExtractor.

Exception in thread "main" java.lang.UnsatisfiedLinkError: org.opencv.features2d.DescriptorExtractor.create_0(I)J
    at org.opencv.features2d.DescriptorExtractor.create_0(Native Method)
    at org.opencv.features2d.DescriptorExtractor.create(DescriptorExtractor.java:127)
    at mainPkg.MainApp.MatchExperiment(MainApp.java:54)
    at mainPkg.MainApp.main(MainApp.java:45)

***** VIDEOINPUT LIBRARY - 0.1995 - TFW07 *****

Based on my understanding of the UnsatisfiedLinkError, it seems the native method DescriptorExtractor.create_0() cannot be found.

Any hint is appreciated...

Add 1

Based on my limited JNI knowledge, I started to search for the JNI declarations in the source code of OpenCV extra modules. It is org.opencv.features2d.DescriptorExtractor missing. So I searched for Java_org_opencv_features2d_DescriptorExtractor. And just as expected, it is not found. So it is never exported as JNI. So I cross my fingers and start to recall... Based on my limited experience with Machine Learning, I remember the jargon feature is intimately related to it. And I remembered I glimpsed some ml in the CMake configuration for OpenCV. So I go through the configuration entries and found this:

BUILD_opencv_ml

And it is NOT selected.

So I checked it. And regenerated the VS project files. And this time I found the Java_org_opencv_features2d_DescriptorExtractor.

Now I am crossing my fingers again and waiting for the new build to complete... Hopefully, it will work...

edit retag flag offensive close merge delete

Comments

Hi, I have the exact same problem after building the wrapper for Java. Did it worked? In case it didn't, can you provide a idea? I'm stuck at this problem.

Thanks!

IordacheStoicescu gravatar imageIordacheStoicescu ( 2017-06-11 16:09:08 -0500 )edit