most sprites, including the player sprites, are 3D models. not still 2D images you can simply grab from the ROM.
ripping means screenshoting each frame as it displays in the DS resolution.

ripping a sprite's code is also utterly pointless, so of course he's not aiming to do that. sorry to say, but please stop talking out of your ass.

turns out there is indeed a lack of proper rips for luigi. I seem to remember there being rips available from google in the past, but I don't find any nowadays. neither mariouniverse or the spriter's resource has it.

a way to record all frames efficiently is to use DeSmuMe's record to AVI feature. keep in mind you may have to record several times over unless you max out the quality settings, thus making the output have many dupe frames so you won't end up skipping some.

you'll have to record while moving around to the fullest of the player's extent, then convert the video to still frames, remove dupe frames, rip luigi from the remaining, and then compile it to a spreadsheet.
having a unicolor background and fully transparent tiles helps as you can't deal with the background everytime you rip luigi. I recommend purple, it's the furthest from green or any color on luigi.

you don't need a locked camera so long as you stay away from the left/right or up/down edges of the level. the camera centers around the player by default.