I may be misunderstanding your request to "grab the poster image" but if you are talking about the cover image that will be in the same folder as the video file, with the same name. You can easily copy that image if you want to use it elsewhere.
There are a few ways to accomplish your naming issue. You can manually edit the .nfo data in JavLuv. Just open the file in question. Make sure to double click the thumbnail of the video cover which will open that file's sub-directory, and onthe Right side of the movie data you can add details, for instance, you could add DeCensored to the Genre information and then a search in Javluv will bring up everything that has decensored somewhere in the file description or .nfo data.
Depending upon your application though here is a much better solution. In windows explorer browse to the parent directory of your file, your folder (Decensored) will be listed in the subfolders. Right click on the decensored folder and choose "Copy as path". Now go back to javluv and in the search bar paste that folder path that you copied, now Javluv will only display the contents of that folder. This, for me, is easier than doing a lot of editing. Let me know if you need more detail or someone with better technical knowledge. Cheers.
One other option you could do but it is a bit convoluted if you already have the files scanned. You could delete the metadata for all of the files that you want to change. Then if they are all in the same folder use a renaming program. I use Renamer Lite. You can configure it to add whatever you like to the end of the file, be careful not to add to the beginning because you will have to unfuck that.
A good practice is to look at the preview to make sure the files are named like youwant. Anyway, use the renaming tool to add some code/word/symbol, whatever it is that will indicate some special attribute that you want to be able to search for. YOu coule add a word or several words, depending on your file structure. IN any case, rename to filenames of those files andthen re-scan them back into Javluv, now when you do a search you can search for one or more of those words you added to the file name. IF you decide to go with the last option you can get renamer lite here:
https://renamer-lite.en.softonic.com/?ex=RAMP-3385.4&rex=true There's other places to download it too. Play with it a bit to get acclimated and make sure to look at the preview before you click change. Cheers. Good luck.
One last little thing, if you decide to use renamer, open the program. In the top window either right click in the open space or double click in the open space, Choose "insert" then on the Right side in the "insert" window type the word or words that you want to add to the end of the file, and them make sure to select "suffix" now click "add Rule" (once you start to play with the program you can add multiple rules but for now stick with the renaming. NOw hit the add folders button and browse to your target folder. Now click preview to make sure that the results (in blue) are what you want. IF they are, click rename. now have javluv rescan the folder and all of your appended names will show up when you search for that name. Sorry about the long dialog.