unsharp vs vapid

unsharp

adj
  • dulled or intentionally blunt. 

  • out of focus; blurry. 

verb
  • To sharpen (an image) by creating a blurred ("unsharp") negative as a mask, and then combining that mask with the original. 

vapid

adj
  • Lifeless, dull, or banal. 

  • Offering nothing that is stimulating or challenging. 

  • Tasteless, bland, or insipid. 

How often have the words unsharp and vapid occurred in a corpus of books? (source: Google Ngram Viewer )