[NDS] What on earth is an .ospr?

[Samevi]

I've been trying to rip a DS game now, and encountered a file format with little to no documentation online whatsoever.
If anyone can help me figure this one out, that'd be much appreciated.

---

Quick update: Using Tinke, I managed to open the game this is from (Meitantei Conan: Kakokara no Zensou Kyoku) and extract/decompress the ospr file.
Running it through TileGGD and setting the image to 32bit per-pixel gave me a greyscale image. Furthermore, it's squished horizontally...
It'd seem that this is the best lead though, if anyone else is willing or able to take a crack at it.

[Raccoon Sam]

the file is compressed with the lz11 format.
Using DSDecmp as DSDecmp ho_ch_107_03_sp.ospr whatever.bin will give you the uncompressed file, and opening it in a graphic viewer like GGD as 8bpp linear will make it all look good. Palettes are in the end-ish part of the file.

[Samevi]

It worked! This is fantastic, thank you very much!