1.6.1-6 VDU Image Linearity

The display should be free of geometric distortion.

Additional Information:
Linearity, the horizontal displacement of a symbol position relative to the symbol positions directly above and below the symbol position, should vary by not more than five percent of the symbol box height. The vertical displacement of a symbol position, relative to the symbol positions to the right and left of the symbol position, should vary by not more than five percent of the symbol box height. Nonlinearity of any column or row should be not more than two percent of the length of the column or row. Lines and columns should be parallel and orthogonal one to the other within the limits of the linearity requirement. This may be expressed as: