Toshiba e-studio281c, Service Manual, Page: 178 / 414

e-STUDIO281c/351c/451c © 2005 - 2008 TOSHIBA TEC CORPORATION All rights reserved
IMAGE PROCESSING
7 - 6
The above averaging operation is performed for all the pixels to accomplish the high reproducibil-
ity of original.
(The following is the case that the low pass filtering is applied on the primary scanning pixel.)
Fig. 7-5
High-pass filter processing
Character outline blurs when the original, such as text, with big difference in density among the
pixels is optically scanned and output from the CCD. Characteristic of the lens and other factors
cause this phenomenon. In this equipment, processing such as edge enhancement is applied
between the targeted pixel and the neighboring pixels to eliminate this phenomenon and realize
high reproducibility of original.
Fig. 7-6
5) Image memory editing
This function performs editing such as enlargement/reduction, mirror imaging, etc., by using a line
memory. Pixel data for one line in the primary scanning direction is stored in the line memory and
the memory is renewed at each line.
- Enlargement/Reduction
Enlargment/Reduction is accomplished by using the line memory control function in the process
of the image processing operation.
<Example> Enlargement
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
Density
After low-pass filter
Primary scanning pixel positions
Density
Primary scanning pixel positions
Solid black area
Original
Image signal
After correction
Low contrast area
100%
200%
1 1 2 2 3 3 4 4 5 5
1 2 3 4 5 6 7 8 9 10