Runnable JAR file

I guess in your code you are using something like "images/some-image.png" and the images folder is in your Eclipse project folder.

Running your stuff inside Eclipse works fine, because the working folder is your project folder.

If you try to run the jar from command line, then usually your current working folder is not the project folder and hence the images cannot be found.

You have to somehow define, where either relative to your working folder or with an absolute path your images are.

The imagepath feature in class ImageLocator might be helpful too.

If my guessing is not right come back with more details on how you do it.

In the eclipse project you will have a particular folder structure.

If suppose you have something like this:
MyEclipsePjct
->src
   ->MySikuli.sikuli

and you might be running from the commandline this 'MySikuli.sikuli' jar

then, you can create a separate folder under this sikuli pjct, say 'Library.sikuli'

MyEclipsePjct
 ->src
   ->MySikuli.sikuli
       ->Library.sikuli ( where you could keep all your images)
       ->your_main_script

and add this piece of code in your script(based on the sample eclipse folder above)

myImagePath = "path_upto_your_eclipse_workspace\\MyEclipsePjct\\src\\MySikuli.sikuli\\Library.sikuli"
addImagePath(myImagePath)