At the risk of commenting on a software that I haven't used personally, I don't think it is possible for ddrescue.
It is a disk/partition imaging software, not a data recovery one. I don't think it even looks at directory structure. In the form of a partition, you just tell it a starting and ending cylinder, then all it does is to somehow copy all the blocks/sectors in-between, without caring or analyzing what those blocks contain.
What you are asking for is the job of data recovery software and it can be done reliably only if the partition table itself is intact (I'm not sure about that in your case). If the majority of the content on the partition can be read without errors, then I would assume that the partition table is good, and you may try programs like "scrounge-ntfs" (only for ntfs partitions) or "safecopy" to try recovering files ignoring errors. Both these programs are available in Ubuntu repositories. All of these software can be run on either the partition itself, or more safely, on the mounted image that you are creating with ddrescue.
That's a good idea. The very purpose of creating images like this is to prevent any further loss due to physical wear & tear.
I'd like to take a minute and thank everyone who's helped me out this far. Even with the bad sectors, this image.dd has helped me recover years of files and memories that would've been lost to broken hardware. Even if everything isn't salvageable, i'm glad to have recovered as much as these programs did. I feel foolish for pushing my computer so far when it began slowing down months ago, but at least now i'll be able to recognize the signs of a failing harddrive.
Currently, i'm picking through the files and backing them up to my new computer. Once that's done, i'll clear space on my external for the ddrescue and start with that project.
Thank you all, again
So i had an interesting thing happen today.
I was going through the .jpg's that Photorec had recovered on my external when i came across some strange files. When made them strange was that when i tried deleting them, i couldn't because of I/O device errors. The thumbnails and previews of many of these images showed complete parts of the image blacked out and missing. I wasn't surprised because i thought this was to be expected.
Then i started scrolling down and I could watch the thumbnails of once-normal files become partially blacked out. Does anyone know what is going on with this?
By the way, did you try to open the files whose thumbnails seemed blacked out (of earlier healthy files)? Thumbnails do not necessarily represent the actual file always and can be dodgy sometimes, especially when there are hundreds of files in a single folder.
However, if the files are corrupt too (like the thumbnails represent), and you are sure they were healthy earlier, then I'm afraid it is also an indication of a failing drive !
If it occurs again, i'll be sure to report back. Once i've gotten this drive clear of the things i need, i'll format and repair it.
But this kind of behaviour can also indicate a hardware failure, ranging from a mere loose connection to a failing drive or motherboard (the I/O controller) or memory leakage.
If any weird behaviour occurs again, you should try running "memtest" (Test Memory) option from the live cd/usb for at least 4-6 hours (recommended duration is 24 hours though). It will give you errors if there is a memory leakage problem. It may also freeze in case of a motherboard problem. But can't test the drive or its connection.