Quality Characteristics In Optical Character Recognition - Siemens SIMATIC MV440 Operating Instructions Manual

Image processing
4.3 Optical character recognition with "Text-Genius" and "Text-Genius Plus" (SIMATIC MV440 only)
4.3.6

Quality characteristics in optical character recognition

Fast feedback about the reliability of the character recognition
To obtain fast feedback about the reliability of the character recognition: In much the same
way as code verification, during optical character recognition, quality characteristics are
calculated and output on the user interface or via the interfaces.
Quality characteristic
Poorest character quality
Highest confusion risk
Minimum character height
Maximum character height
Average character quality
Average confusion risk
Assignment of the numeric evaluation of OCR to the quality levels
Grade
Poorest character quality (OCQ)
Highest confusion risk (OCC)
Minimum character height (OCL)
Maximum character height (OCH)
Average character quality (OAQ)
Average confusion risk (OAC)
84
Value output
The value output is the poorest (lowest) probability value of all the
characters found.
Since plain text cannot be uniquely identified, a probability is
calculated for a character that is found. This can be interpreted as a
match between the printed a theoretical, "ideal" character.
The value output is the poorest (lowest) probability difference of all
the characters found.
For each identified character position, up to seven character
hypotheses each with their own probability are calculated. The
hypothesis with the highest probability is selected as the read result
for the character position. The confusion risk is the difference in
probability between the two hypotheses with the highest evaluation.
Height in pixels of the smallest character found measured
perpendicular to the reading direction.
Height in pixels of the highest character found measured
perpendicular to the reading direction.
Average probability of all characters found
Average probability difference for all characters found
4
≥ 208
≥ 208
> 26
and
≤ 30
> 26
and
≤ 30
≥ 208
≥ 208
Operating Instructions, 04/2013, A5E02371045-06
3 2 1
≥ 156 ≥ 104 ≥ 52
≥ 156 ≥ 104 ≥ 52
> 30 and ≥ 20 and ≥ 45 and
< 40 < 25 < 50
or
≥ 40 and
< 45
> 30 and ≥ 20 and ≥ 45 and
< 40 < 25 < 50
or
≥ 40 and
< 45
≥ 156 ≥ 104 ≥ 52
≥ 156 ≥ 104 ≥ 52
SIMATIC MV420 / SIMATIC MV440
0
< 52
< 52
< 20
or
≥ 50
< 20
or
> 50
< 52
< 52