Need Help Ripping From a PSP Game

[Samevi]

Hey there. I'm not particularly new - I've ripped from two 3DS games so far, those being Detective Conan: Phantom Rhapsody and Detective Conan: Marionette Symphony (the latter of which I'm still working on), but I'm curious about how to rip sprites from a specific PSP game; Detective Conan: Prelude from the Past (or Meitantei Conan - Kakokara no Zensou Kyoku).

Now, I've got the ISO already, but I don't really know how to proceed at all. This is rather different than the kinds of things that ripping from 3DS games requires, so any help would be much appreciated.
Also, I've tried playing through the game and dumping sprites as I go, but that seems particularly inefficient, since I don't know Japanese and there is no English version or even a patch of the game, which is required to properly progress due to puzzle elements - so if at all possible, I'd like to avoid that.

UPDATE: I've discovered the sprites are packed in .gim files - along with that, I've discovered a neat program that allows me to convert gims to PNGs (GimConv). The only problem is that it only cuts a small portion of the sprite and converts that. If anyone can help me figure out how to use that software to get a full sprite, that'd be a big help!

[Raccoon Sam]

GIM files are to PSP what TIM files are to PS1 and TM2 files to PS2.
Try GimConvert. If that doesn't work either, the files may be compressed. Please upload as many as you can here so let's take a look!

[Samevi]

GIM files are to PSP what TIM files are to PS1 and TM2 files to PS2.
Try GimConvert. If that doesn't work either, the files may be compressed. Please upload as many as you can here so let's take a look!

It works better than what I was trying, for sure. However, it seems that it's only ripped some parts of some sprites. It's either the sprite's right elbows or darkness. I'll upload a file containing some of these .gims (and accompanying .bins that I failed to mention) as suggested.