VI User Manual - 第272页
Optical Character Verification 8 - 10 Vision 2007 4.10 User Manual Re v 01 8.2.4.2 Running To reduce cycle time, the confusion algorit hm is only executed in certain conditions. Each letter has its own decisi on score to…
Optical Character Verification
Vision 2007 4.10 User Manual Rev 01 8 - 9
8.2.4 Confusion algorithm explanation
A Confusion algorithm can be auto-
matically performed when verifying
characters to avoid false detection
8.2.4.1 Teaching
The definition of the characters that can be confused is totally automatic.
Example: for the letter O, there is 1 confusion letter: G.
When training the letter O, the score of the model G was 84 which is between 65 and
100. That is why G is a confusion letter.
The Confusion algorithm consists in trying models previously identified as Confusion
letters.
If the model of the Confusion letters returns a higher score than the model of the
letter we are about to verify the system returns an error.
Ex: the system verifies a O but in reality it a G.
On the real picture, the score of the model O = 82
On the real picture, the score of the model G = 84
So it is not a O, but it is a G! The system returns an error.
A maximum of 3 confusion letters is possible. They are ordered by the score
obtain during the test on the original picture.
0 100
Score minimum
If score of another model is between
these limits:
this model will be added in the list
of the confusion letters
Score maximum
Unacceptable score
65
Creation procedure
Optical Character Verification
8 - 10 Vision 2007 4.10 User Manual Rev 01
8.2.4.2 Running
To reduce cycle time, the confusion algorithm is only executed in certain conditions.
Each letter has its own decision score to activate the Confusion algorithm; it is called
the Confusion score.
Example 1
The system verifies a O and it is really a O.
The score of the model O is higher than the Confusion score, the confusion algorithm
is not executed.
Example 2
The system verifies a O but in reality it a G.
The score of the model O is lower than the Confusion score, the confusion algorithm is
executed.
When to start the Confusion algorithm ?
8.2.5 Test of one letter
1. Select the picture.
2.
Scroll to the letter which you want
to test on the center of the alphabet
A Joker letter is a letter which is
not tested.
To change the character drawing, tick the 3 check
boxes (A):
Photo Coarse Grain Fine Grain
For example, if you deci-
de that A is a joker letter,
then all A in you text will
be not tested.
0 1008780
Acceptable score
Confusion algorithm executed
Confusion score
Unacceptable score
Confusion algorithm
NOT executed:
the letter has been found
with its model
A
B
+ =
+ =
+ =
+ + =
Photo + Fine grain
Photo + Coarse grain
Fine grain + Coarse grain
Photo + Fine grain + Coarse grain
Creation procedure
Optical Character Verification
Vision 2007 4.10 User Manual Rev 01 8 - 11
Click on the icon (B) to display all trained characters
in the opposite window.
In order to not test a character, put them in quaran-
tine with horizontal arrows.
To change the order of the execution of the models,
use the vertical arrows.
To delete one or more models, select them in Cur-
rent letters or Letters in quarantine, and click on
Dustbin icon.
3. Draw the area on the image.
4. Click on Test button to test one model, the result is shown in the table.
If the character is in quarantine, a cross appear in the second column
.
If the Confusion is activated, the algorithm confusion is launched if necessary. If it is the
case, the letter of confusion appears in the table.
If you want to test all the models of the current character, use the Test All button
The winner letter is notified by a cross (You can use the algorithm confusion too)
Creation procedure