CognitiveTPG B780 - Manual (Page 146)

Chapter 5: Programming commands 134
A776 (B780) Programming Guide A776-PG00001 C 12/09
r specifies the number of saved gray levels = scale resolution (default value = 0) as follows:
Value Definition
0 No change from previous setting
1 Minimal noise cleaning preserving 128 gray levels
2 Low Standard noise cleaning preserving 64 gray levels
3 High Standard noise cleaning preserving 32 gray levels
4 Maximum noise cleaning preserving 16 gray levels
5 No noise cleaning and full 256 gray level as captured is preserved, default
Return: None
Description: The parameters set the image’s internal orientation and number of scanned gray levels. The internal
format of the image is always 256 level gray scale, one byte per pixel; when sending to the host a reformatting (if not
raw) is then done when needed. Normally 16 – 32 gray levels are suggested for viewing on displays, thus allowing
more effective LZW compression while preserving distinguishable artifacts of a gray scale image. A TIFF structure is
used to return all formats. This structure holds height & width and other document identifying tags as well as images
of both sides.
The newest configured values are retained in non-volatile memory, persisting across power cycles.
Configure Binarization Methods and Attributes
Hexadecimal: 1D C5 nL nH m d1 – dn-1
Parameters: n is the number of bytes that follow. n values of 1 indicate a choice of threshold method only without
changing methods properties. m selects the threshold method and optional attributes that the application may
choose to set: m= 0 reserved for future; a dynamic function threshold method based on experience lookup tables;
m = 1 (default) selects the US banking average area threshold method, m = 2 selects fixed value thresholding, m >2
reserved for future other method(s) that may be standardized by the industry. Any dx value = 0 sets the attribute at its
default value. Any dx value not sent will remain unchanged.
Method M d1 d2 d3
Dynamic (Future) 0 Black bias cross point, 5
<=d1<=95; default =50 NA NA
Averaging 1 % difference from average,
5<=%<=95; default = 20% Reflectance below which pix is
always black; default = 51 Reflectance equal or above
which pix is always white;
default = 178
Fixed Threshold 2 The reflectance value to
be used, 1 <= d1 <= 254,
default = 96. NA NA
For m = 0, the bias cross point selects where favoring black pixels changes over to favoring white pixel.
The averaging method uses 20% as the default difference for a pixel to be judged different than an 1/8” square
background average. Absolute values are also used to decide on a pixel’s color (either black or white).
The fixed threshold method uses a simple comparison test against the value.
Return: None
Description: This allows for selection of threshold method and tweaking of any threshold method variables. These are
used when TIFF G4 binary format for the transferred image is selected.
The newest configured values are retained in non-volatile memory (persist across power cycles).