KEYENCE SR-750 Series - Manual (Page 23)

23 E SR-750 UM
ISO/IEC TR 29158 (AIM DPM-1-2006)
Decode success/failure DEC (Decode)
Description Evaluates whether decoding is possible or not.
―
Calculation
formula
―
Criterion ―
Cell contrast CC (Cell Contrast)
Description
Evaluates the difference between the average
brightness value of bright cell (ML) and
average brightness value of dark cell (MD).
Calculation
formula
CC = (ML - MD)/ML
ML : Average brightness value of bright
cell
MD : Average brightness value of dark
cell
Criterion
A : more than 0.30
B : 0.25 to 0.30
C : 0.20 to 0.25
D : 0.15 to 0.20
F : less than 0.15
Cell modulation CM (Cell Modulation)
Description
Evaluates the variation degree in cell
brightness
― Calculation
formula
[White cell]
CM = (R - GT)/(ML - GT) (When R
≥ GT)
[Black cell]
CM = (GT- R)/(GT- MD) (When R
< GT)
R : Brightness value
GT : Binarization threshold value
ML : Average brightness value of bright cell
MD : Average brightness value of dark cell
Criterion ―
Reflectance margin RM (Reflectance Margin)
Description
Evaluates the variation degree in cell
brightness with black and white of the correct
cell considered.
―
Calculation
formula
[White cell]
R >= MARGIN = (R-GT)/(ML-GT)
R < GT
→ MARGIN = 0
[Black cell]
R < GT
→MARGIN = (GT-R)/(GT-MD)
R >= → MARGIN = 0
MARGIN : Margin of each cell
R
: Brightness value
GT : Binarization threshold value
CC : Cell contrast
Criterion ―
Fixed pattern damage FPD (Fixed Pattern Damage)
Description
Evaluates the degree of the fixed pattern
damage (area on the right) dependent on the
code type.
Calculation
formula
―
Criterion ―
Format information damage
FID
(Format Information Damage)
Description
Evaluates the format information damage
degree of QR code.
Calculation
formula
―
Criterion ―
Version information damage
VID
(Version Information Damage)
Description
Evaluates the version information damage
degree of QR code (Model 2, version 2 and
later versions).
Calculation
formula
―
Criterion ―
Axial nonuniformity AN (Axial Nonuniformity)
Description
Evaluates the distortion degree in vertical and
horizontal size of the code.
Calculation
formula
AN = abs (Xavg - Yavg)/((Xavg + Yavg)/2)
Xavg : Average cell size in horizontal
direction
Yavg : Vertical cell size in horizontal
direction
Criterion
A : less than 0.06
B : 0.06 to 0.08
C : 0.08 to 0.10
D : 0.10 to 0.12
F : more than 0.12
Grid nonuniformity GN (Grid Nonuniformity)
Description
Evaluates the maximum position slip of each
cell
Calculation
formula
GN = Hmax/X
Hmax : Maximum position slip amount
X
: Cell size
Criterion
A : less than 0.38
B : 0.38 to 0.50
C : 0.50 to 0.63
D : 0.63 to 0.75
F : more than 0.75
Unused error correction
UEC
(Unused Error Correction)
Description
Evaluates the ratio of error correction unused
at the time of decoding.
―
Calculation
formula
UEC = 1.0 - ((e + 2t)/(d - p))
e : Number of code words that cannot be
read
t : Number of error code words
d : Number of error corrected code words
p : Number of error detected code words
Criterion
A : more than 0.62
B : 0.50 to 0.62
C : 0.37 to 0.50
D : 0.25 to 0.37
F : less than 0.25
Print growth (horizontal)
PGH
(Print Growth Horizontal)
Description
Evaluates the mark cell growth in the
horizontal direction.
Calculation
formula
(D - 0.5)/0.15
D : On the horizontal clock pattern
Ratio of the number of pixels of mark
cell
Criterion
A : -0.50 to 0.50
B : -0.70 to -0.50 or 0.50 to 0.70
C : -0.85 to -0.70 or 0.70 to 0.85
D : -1.00 to -0.85 or 0.85 to 1.00
F : less than -1.00 or more than 1.00
Print growth (vertical) PGV (Print Growth Vertical)
Description
Evaluates the mark cell growth in the vertical
direction.
Calculation
formula
(D - 0.5)/0.15
D : On the vertical clock pattern
Ratio of the number of pixels of mark
cell
Criterion
A : -0.50 to 0.50
B : -0.70 to -0.50 or 0.50 to 0.70
C : -0.85 to -0.70 or 0.70 to 0.85
D : -1.00 to -0.85 or 0.85 to 1.00
F : less than -1.00 or more than 1.00