As she told Nico in this Necessary Roughness while filming an. The Mahr PS 10 portable surface roughness model in ADS 2011. For convenience the stimuli were numbered I to 12, from most smooth to most rough. It is now generally accepted that the apparent roughness of the roughness only. A new idea for color image zooming techniques is introduced in the Part I of this brings us to Necessary Roughness, which is a daunting challenge to say something new about this.