Cognex DataMan Communications And Programming Manual page 44

Property
reflectMin
edgeContrastMin
Type 1D Standards
Metric 1D Readability, ISO/IEC
15416
Metric 1D Readability, ISO/IEC
15416
44
DataMan Application Development
2D Standards
The reflectance
minimum. This metric
measures how dark
the dark part of a
barcode is. A low
value indicates that
the dark parts of the
code are dark, and a
high value indicates
that they are not. A too
low value may
indicate that there is
not enough light or
too short exposure
time is being used. A
too high value might
indicate a hotspot, too
much light, or that a
too high exposure
time is being used.
Print quality troubles,
like a printer
depositing less ink
than intended, may
also be indicated by
the minimum
reflectance grade.
The edge contrast
minimum measures
the ratio of minimum
edge contrast to the
maximum contrast in
the symbol. The
metric is designed to
pick up any artifacts in
the symbol, such as a
damaged bar, which
generate low contrast
variations in the
symbol. A poor grade
here might indicate
poor focus in the
optical system, poor
lighting, or poor
printing.
Description