Canon DR-2580C Service Manual page 54

CHAPTER 2 FUNCTION & OPERATION
iii) The front side of a document is overlaid
on the back. And the part of the over-
lapping images, in which the black
points of the front and back sides
overlap one another, is extracted from
the target image area (margins with the
width of 20 mm). And then, an image
data is created. This image is called
hole pattern image.
If there are some binder holes, a hole
pattern image is created.
20mm
Figure 2-525
iv) In case that both the front and back
side images have some black objects
(which are not binder holes) on the
same spots in the previous step, those
should be determined as holes and a
hole pattern image should be created.
Thus, some black objects other than
those binder holes will be deleted as
well. In this case, the low-pass filter
processing should be done to handle
and delete small objects.
v) The shapes (such as area, circumfer-
ence, and center of balance) of the
binder holes of the hole pattern, front
and back side images are compared. If
they are the same, those black objects
are determined as binder holes. And
then, they are removed from the front
image.
2-28
vi) In case that both sides of document are
The binder hole removal function does not
successfully work under the following
conditions.
• In case that a binder hole and figure or
20mm
COPYRIGHT © 2005 CANON ELECTRONICS INC.
scanned, after the binder holes on the
front image are removed, those on the
back side image are removed as well.
character overlap one another, the binder
hole is not removed because the shape
of the hole on the front should be different
from that on the back. However, if the
object which overlaps a binder hole is a
thin line which can be deleted by the
low-pass filter processing, the hole is
successfully removed.
(Front)
Figure 2-526
CANON DR-2580C FIRST EDITION APR. 2005
(Back)