How to Remove Mask or Corrupted Image from PDF?

I am new in programming as well as in ruby on rails.

I want to remove mask images or i can say corrupted images from extracted content and images from PDF. I have a extracted data from PDF which contains all text and images of PDF. When i display that text and images at that time it show's some bad or corrupted images. I want to remove all those images from my page.

Anyone can help me out?

Sorry for silly question.