The original is a CGI creatd in Photoshop.

Gaussian Blur in gamma spaces do not bite to deep shadows correctly because of the very steep gamma function there.

In fact all computer generated shadings need to be rendered in linear space in order them to appear natural.

Linear space processing

1. Open the original CGI.
2. apply Gaussian Blur at radius=1.2.
3. apply inverse gamma 2.2.
4. save as accurate gi

Gamma-space processing

1. Open the original CGI.
2. apply inverse gamma 2.2.
3. apply Gaussiaan Blur at radius=1.2.
4. save as accurate gif