[fitsbits] Question - FITS support & difficult to read images

[Andy]

 Hi group.

  I am currently finishing a shareware/freeware program (PC) to
read/write and apply effects to a range of image formats; including
Fits/Pds/Vicars amongst 20ish other formats. These 3 formats read only
any need to create them ? . 
 
  Does anybody have any difficult to read files that are known to
contain image data ? - if please post.

  TIA.
  
  Andy