# Accept Threshold

For every character it attempts to classify, an OCRMax tool generates a matching score for all the characters in the trained font. Matching scores range from 0.0 to 1.0, with 1.0 for a perfect match. The tool compares the highest matching score to an accept threshold, and gives the character a preliminary Read result when the matching score exceeds the accept threshold. By default, an OCRMax tool uses an accept threshold of 0.8, but you can raise or lower the value as necessary for your vision application.

The accept threshold allows you to vary the sensitivity of the OCRMax tool to character and image variation. As you increase the accept threshold, the OCRMax tool will require a better match between the character in the string and the trained character in the font file.

Raise the accept threshold when your vision application acquires good images of the character strings you want to classify, with characters of consistently good print-quality, and that exhibit little change in rotation and skew. A high accept threshold can improve the execution speed of the tool. If you set the threshold too high, however, the tool will fail to classify one or more characters in the string.

Lower the accept threshold when your production environment cannot ensure a consistent appearance for each character. If, as you are developing your application, the OCRMax tool fails to classify characters correctly, try lowering the accept threshold.