Yep much the same way as they are originally created check out redump.org if you have any actual interest in doing that.
ISObuster can be used as well as Exact Audio Copy if you want to do it the best possible way (the most perfect copy you can get having the tracks split up and various compression/re-encodings ect done to get the ecm+ape+cue combo).
Exact Audio Copy would need the disc image mounted (shame as ISObuster does not), to be honest I'm not a fan of that, it makes rebuilding a usable disc image a bit of a pain, don't mind the ecm bit it gives good compression in 7-zip but don't feel the need to split the tracks up, but it does give a bit of extra space back.
P.S. that is not done so much to save space on a HDD/Server but more to enable easier/quicker downloading (easier because large files have a greater chance to mess up during downloads, but I use a DL manager that helps big time to avoid such issues) [You can't use those disc images as it downloaded like that they do require converting first so not the best method for noobs I guess].
I like using ecm for uploads as it making it quicker to upload as well as download, but for playing I keep my collections for emulation in Bin+Cue format or ISO depending if the disc images are CD or DVD.
Games I have collected for burning ecm or for use with other consoles (PSP via emulation/iso and xbox via emulation as well as disc images for the respective consoles) is fine for those are not going to be actively used so would have those ecm'd for storage.
P.S. Akumajou Dracula X - Gekka no Yasoukyoku (Japan) (v1.2) [En by Gemini+Throughhim413 v1.0] I don't know exactly what that one is but it is an english translated version of Castlevania it might not be the same as the PSP version but it should have subs in english while keeping the Japanese extra's (I presume voices aswell)
I was about to look at this today a little bit, went to get the files anyway, I may still do the re-translated Eng dubs/Eng subs and Jap dubs/Eng subs versions though as these are re-translated in the PSP version (the game on the PSP is based on the Jap version rather than the English versions, or rather a mix of the two)
I will not be rushing into this just thought I would take a quick look, alot of the PSX is emulated in the PSP version but it is a mix of PSP sound and movie files and PSX original files, so it is a pick and mix of formats used between PSX and PSP, so there is a bit of work needed to get the correct format then it is a case of rebuilding the files, I will need to dig out some really old tools to do all of that and possibly Win98
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