Thank you. Yes, you are right. Sorry. I am used to png with level of compression. It is surprise for me that png is lossless..
https://en.wikipedia.org/wiki/Portable_Network_GraphicsUnfortunately if I use [Ctrl]+[s] or [s] Verve doesn't produce png output correctly on my machines (desktop at home with AMD Radeon 5850, laptop in the office with AMD Radeon HD 7400M ).
[Ctrl]+[s] and [Ctrl]+[Shift]+[s] both work correctly.
Attached is the example of the result png (black image) and jpg snapshot of the source "painting".