Phtcache.bin

File header:
00000-00007: Header 1UJQ00_1
00008-0000B: Number of pictures plus 1 (why?)
0000C-00011: Unknown value (seems to be static?) B80B01000000
00012-00013: Total number of photos (excluding 2D dups)
00014-00017: Appears to be file size. It's only 32 bits = 4GB max. A few hundred K
                larger than the actual size of every file in DCIM (?)
                1607971 vs DCIM/100NIN = 1441792 vs DCIM = 147560 vs files = 1409024
                vs non-disk usage = 1224857
                phtcache non-disk = 456024, disk = 458752
                phtcache (non) + files (non) = 1680881 - 1607971 = 72910 = 72K hmm...
                maybe the 72910 is some kind of checksum?
                ( I have no clue, all these notes were probably worthless)

From 0x0018, one block per picture. Each block is 0x98 bytes long and formatted as such:
00000-00003: Preferred image file format. Should be MPO\x00 or JPG\x00. The inner cam is the only
                one that will yield JPG. 3D pictures are taken even with screen switched to 2D.
00004-0000B: Name of image
0000C-00013: Subfolder of image
00014-0001B: Time taken based on "DS epoch" (start of 1/1/2000) (UNIX+946684800)
0001C-00023: Time last viewed?
00024-00027: UNKNOWN 
00028-0002B: UNKNOWN
0002C-0002D: UNKNOWN
0002E-0002F: UNKNOWN
00030-0003F: UNKNOWN
00040-00043: File size

File Header

Name	Size	Description
Unknown	0x08	always 1UJQ00_1
Number of Pictures	0x04
Unknown	0x05	seems to be static?
Total number of photos	0x01	excluding 2D dups
Unknown	0x05	File size?
Pictures Property	0x98 * Number of Pictures	Index refereed by 3DS Camera

Pictures Property

Name	Size	Description
Extension	0x04