IJ-openCV version of Update site vs github


I have a question about IJ-openCV, specifically the version of the update site and the github repository. Both provide version 1.2.1 of IJ-OpenCV-1.2.1.jar but in the one from the update site some converter modules seem to be missing.
In Eclipse using the dependency


in the pom.xml the converters are available.
In FIJI via the update site of IJ-openCV the methods are missing:
Exception in thread "Run$_Thread-5" java.lang.NoSuchMethodError: ijopencv.opencv.MatImagePlusConverter.toImagePlus(Lorg/bytedeco/javacpp/opencv_core$Mat;)Lij/ImagePlus;

Manually replacing the jar with the one from the github release solves that.

Will the version on github migrate to the update site eventually? Or is there a better way to convert from openCV mat to ImagePlus I’m not aware of jet?

Any help or info is much appreciated.
Many thanks,

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… also regarding the IJ-openCV update site: it deliveres javacpp and javacv jars in version 1.4.2. I stumbled upon a bug fixed from javacpp 1.4.4 on. Can I make a request to include at least these versions, or does that breake a whole lot of other things /other reasons to stick with the included versions?
I just found out on the IJ-openCV Github pages that issues should be reported there or to @joheras and/or @LThomas. Since I started here in the forum I hope it’s ok if I continue to post this here. Otherwise I’ll open an issue over there, whatever is more approriate.


Hi Manuel,

I remember adding this conversion method in a PR, apparently I did a release on GitHub stating that it’s the same as the Fiji version but I don’t actually have the update rights on this site, so it might not have been the case sorry :sweat_smile:

@joheras could you upload the latest release version from GitHub to the update site as suggested ?

Not that I know, but before the PR I mentioned above one had to first do Mat > ImageProcessor and then ImageProcessor > ImagePlus, so this should work with the current version on the update site.

It does not seem to be a code-breaking update if the versioning is correct (minor version change right?).
We could give it a try, testing plugins we know to use javacpp/javacv.
I know @Christian_Tischer also uses it for some stuff.

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Hi Laurent,

great, many thanks! I’ll try to first convert to ImageProcessor and then to ImagePlus, if that works out that’s solved.

The bug in javacpp/javacv occurs for me only in Win7, but unfortunately we’re stuck on a microscope PC with that currently.

Again, thank you & best regards,

Thanks for thinking about me, but don’t worry as my code for this is not really in use.

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Sure, I will upload the latest release version from GitHub to the update site.

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Thanks @joheras.

@manugu I wanted to test with version 1.4.4, I could find javacpp and javacv 1.4.4 on Maven central but not the corresponding opencv artifacts from bytedeco.

Like currently the update site ships opencv-3.4.2-1.4.2.jar and a bunch of platform specific jars, and I believe the version should match javacpp, so I was looking for opencv-x.x.x-1.4.4.jar but I could not find it anywhere. Any clues ?

Hi @lthomas,

I could find this:
But I have not tested that yet!

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Great, however it means changing the opencv major version from 3 to 4.
Hopefully it wont be much of an issue…
I will test that, I put here a link to the artifacts to replace in Fiji.app/jars to test this version 1.4.4/4.0.1
I could not upload directly the zip on the forum (too heavy maybe ?)

Feel free to try it too @joheras with your plugins :wink:

Great thank you @LThomas!
Putting the jars in works, at least on my end. Hopefully for you all too :wink:
Your collection of jars is really helpful.

I just noticed that core FIJI also comes with javacv1.4.4 and IJ-openCV replaces that with 1.4.2 at the moment, but that just as a side remark.

Best regards,

Works for me too ! And I also tested the template matching plugin from Tseng with this new version and it works too.

Interesting, I think you mean javacpp though no ?
This means the IJ-OpenCV update site wouldn’t need to ship that dependency :slight_smile:

yes, I meant javacpp1.4.4 :sweat_smile: