View Thumbnails in iPod touch? (.ithmb)

I explored "Raw File System" of my iPod touch with i-FunBox and I found a folder with two .ithmb files (120x120.ithmb and 158x158.ithmb). These took about 50mb in my iPod and I found that these are photo cache.

Is there any free software to convert these files for PC? I tried ithmbconverter but I must pay.

I searched every website and I didn't find anything.

Thanks