This is a small tool which I developed for personal use but I thought it might be useful for some other hacks. Recently I began on hacking Rune Factory 4 with good success so far and this game has tons of BCTEX files which I wanted to edit. After analyzing the format and messing around with "Every File Explorer" I learned that editing these files isn't that difficult.
You can actually open BCTEX files with Every File Explorer but the only problem is that the saved file is not correctly formatted for BCTEX. So I kept a backup of the original files and compared them and it turned out that restoring the header of the original file, as well as deleting a sequence of 30 Bytes at the end of the file made it work properly. Then I did the same with BCTEX files which contain multiple images and it worked as well.
However having to open a Hex-Editor for each graphical change is a bit annoying so I decided to develop a tool which does exactly the same thing but faster:
How does it work?
The screen shows multiple replaced BCTEX files.
You can also restore multiple BCTEX files by selecting folders which is useful if you make multiple texture changes and don't want to select each file.
As I already mentioned: I made it for personal purposes and therefore cannot guarantee that it works 100% for other games but it might be worth a try for you.
I hope it helps some people.
You can actually open BCTEX files with Every File Explorer but the only problem is that the saved file is not correctly formatted for BCTEX. So I kept a backup of the original files and compared them and it turned out that restoring the header of the original file, as well as deleting a sequence of 30 Bytes at the end of the file made it work properly. Then I did the same with BCTEX files which contain multiple images and it worked as well.
However having to open a Hex-Editor for each graphical change is a bit annoying so I decided to develop a tool which does exactly the same thing but faster:

How does it work?
- Keep a backup of the file/s you want to edit
- Open BCTEX files in Every File Explorer and import your PNG-Replacement. (You have to filter all files as EFE doesn't recognize BCTEX files with it's default filter)
- Save your file and open BCTEXRecreate
- Choose your Backup and your changed file and click on "Restore Information"
- Create your RomFS and try it out: You should now see your changed BCTEX graphics

The screen shows multiple replaced BCTEX files.
You can also restore multiple BCTEX files by selecting folders which is useful if you make multiple texture changes and don't want to select each file.
As I already mentioned: I made it for personal purposes and therefore cannot guarantee that it works 100% for other games but it might be worth a try for you.
I hope it helps some people.