How to rip sprites/backgrounds from Wonder Project J2?

[SEAMUS]

I tried to rip sprites from this game before, but the graphics are a bunch of segmented textures because of the Nintendo 64's notoriously low 4 Kb texture cache. They seem to use 8-bit color palettes from a 16-bit color base. I can't seem to see anything in the ROM because the data is compressed aside from the color palettes. Also, next to no one has documented this game's data.