Add Blur cpp example and improve image error handling

[Mikolaj-Filar-Mobica]

This pull request includes a blur example written in C++ and a minor improvement to image error handling.

[pwisniewskimobica]

@bashbaug Thanks for comments As @Mikolaj-Filar-Mobica leaved the project I took this PR and made fixes for your remarks. Please take a look Regards

[pwisniewskimobica]

@bashbaug Thanks for review All of remarks done -->waiting for approve&merge

[pwisniewskimobica]

Fixed