# Clean Print Mode

By default, an OCVMax tool allows the character strings in the images you acquire to exhibit a wide range in various degrees of freedom from one image to the next. In addition, using Standard Mode allows your strings to be verified in an array of lighting conditions, as well as allowing the tool to be trained despite the level of image noise in the background.

An OCVMax tool also supports Clean Print Mode, which you can use to verify character strings but only if your acquired images show a great deal of consistency with respect to several characteristics. Specifically, all your acquired images must have all the following qualities to be candidates for Clean Print Mode:

- Little to no rotation
- Uniform scale
- Little or no image noise

For example, the following series of images are valid candidates for Clean Print Mode:

A new OCVMax tool is configured for Standard mode by default. If you switch to Clean Print Mode, the OCVMax tool restricts the Angle and Uniform Scale degrees of freedom to an allowable range, overwriting any settings you might currently have. In addition, the tool disables other degrees of freedom from consideration, such as shear and non-uniform scale.

In addition, be aware of the following usage notes regarding Clean Print Mode:

- You should attempt to limit the enabled character set in the selected font to as few characters as possible.

  An OCVMax tool might fail to train a character string that uses a large character set.

- Candidate strings for Clean Print Mode require a higher level of contrast than images that can be analyzed in Standard Mode.

  Normally, character strings require a contrast of 30 grey levels between characters and background. In Clean Print Mode, character strings should have a minimum contrast between 60 and 100 grey levels.

- An OCVMax tool typically yields better results when 5 to 8 pixels of white space exists below the string.

- You do not normally need to perform tuning when you use Clean Print Mode.

  Tuning an OCVMax tool with Clean Print Mode enabled can require a significant amount of time.

See the following sections for more information: