Orbotech Symbion S36, Руководство программиста

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© Orbotech 2005 Symbion™ Programmer Guide 75
Draft - Confidential
OCR Parameters
The following parameters controlling the OCR Engine are available;
•
Expected Text defines the text to be read from the OCR Inspection Area,
the text may be entered using wildcards (
* ?
)
Regardless of the text entered in Expected Text if the
Minimum Length or Maximum Length conditions are set and
not met the Inspection will fail.
•
Type describes the marking type, as Black on White , White on Black or
Laser Etched
The chosen Type determines the default lighting used initially
•
Filter can be set to apply a filter to the processed image prior to reading.
Two Filter types are available, Blur and Median each may be applied with
a factor from 1 to 4
Filters can be used to improve contrast in the processed image.
•
Brightness Offset will manipulate the processed image
When the offset is
0
the image is processed automatically. Setting an
offset can reduce noise in the image.
The offset may be both +ve and –ve
•
Orientation determines the direction (relative to the component) in which
the text should be read.
Setting default the system reads the text from the component orientation.
•
Dust Size [mm] defines the smallest object that may be read as text.
Setting
0
the system attempts to read all objects.
Use the ruler to check the size of objects in the processed
image
•
Max Char Size [mm] defines the largest object that may be read as text.
Setting
0
the system attempts to read all objects.
•
Min Font Aspect Ratio [%] and Max Font Aspect Ratio [%] define rules
for the ‘shape’ of characters.
Setting
0
the system attempts to read all objects.
The Aspect Ratio is calculated as Width / Height