Do I have to pay for PictView?

No, definitely you do not have to do so. However, if you think that PictView is good and that its support should be continued, you can sponsor its further development. The development may include (but is not limited to) adding support of new formats, extending the current support, adding new features, porting to other systems. We are currently working on versions for MS Windows, supporting also command-line conversion. You can already check beta versions. Commercial 32bit DLL libraries for image decompression and conversion are also provided.