APPENDIX - A. Image Processing Example A-1 Fixed Threshold ..................................................................................... 1 A-2 OCR DTC (Dynamic Threshold for OCR)............................................ 2

A-2.1 Ball Point Pen Fiter ............................................................................................. 2 A-2.2 Gradation............................................................................................................. 3 A-2.3 Threshold Table................................................................................................... 3 A-2.4 Noise Removal.................................................................................................... 4 A-2.5 Smoothing ........................................................................................................... 6

A-3 Form DTC (Dynamic Threshold for FORM) ........................................ 7 A-3.1 Sensitivity ........................................................................................................... 7 A-3.2 Threshold ............................................................................................................ 7

A-4 Dither....................................................................................................10 A-5 Minimize Average Error.......................................................................12 A-6 Random Dither .....................................................................................15 A-7 Filter .....................................................................................................17 *) Depending on the scanner yo

the sample image indicated in

P3PC-E087-02ENC2

u use or the document you scan, an actual scanning result may differ from this document.

Back to “Image Processing Software Option User’s Guide” >

1

A-1 Fixed Threshold

Original

Threshold = 192

Threshold = 128

Threshold = 64

User’s Guide →

2

A-2 OCR DTC (Dynamic Threshold for OCR) A-2.1 Ball Point Pen Fiter

Ball Point Pen Filter = OFF

Ball Point Pen Filter = ON

User’s Guide →

3

A-2.2 Gradation

A-2.3 Threshold Table

Gradation 0 Gradation 1 Gradation 2 Gradation 3

Threshold Table 0

Threshold Table 1

Threshold Table 2

Threshold Table 3

Threshold Table 4

Threshold Table 5

Threshold Table 6

Threshold Table 7

4

A-2.4 Noise Removal

Original (Noise Removal=OFF)

Noise Removal = 2x2 Noise Removal = 3x3

Noise Removal = 4x4 Noise Removal = 5x5

5

Noise Removal = 2x2

Noise Removal = 3x3

Noise Removal = 4x4

Noise Removal = 5x5

6

A-2.5 Smoothing

Smoothing = OFF

Smoothing = IMAGE

Smoothing = OCR

7

A-3 Form DTC (Dynamic Threshold for FORM) A-3.1 Sensitivity

A-3.2 Threshold

Sensitivity=0 (Threshold=128) Sensitivty=255 (Thr

Sensitivity=24, Threshold=128

(Sensitivity=24) Threshold=0 (Sensitivity=24) Thr

eshold=128)

eshold=255

User’s Guide →

8

Adjusting Sensitivity Default Sensitivity=24 is noisy. There are 2 ways to reduce noises.

1. Set higher value (ex. Sensitivity=32). Sensitivity is reduced but noises are reduced. 2. Use Average 3x3 Filter. Sharpness is lost but noises are reduced.

Sensitivity=32, Threshold=128

Sensitivity=24, Threshold=128

Sensitivity=24, Threshold=128 + Average 3x3

9

Adjusting Threshold Sensitivity is decided next to adjust the Threshold for background to be best suited.

Threshold=64

Threshold=128

Threshold=192

Using Average Filters In FORM processing, usually document condition are not good. Use of average filter is recommended. ‘Average 3x5 Filter’ is effective, if resolution is not required. ‘Average 3x3 Filter’ is effective, in typical cases.

Average 3x5 + FORM DTC (Sensitivity=24, Threshold=128)

Average 3x3 + FORM DTC (Sensitivity=24, Threshold=128)

10

A-4 Dither See also A-5 for “Adjusting Brightness”, “Adjusting Contrast”.

Dither 0

Dither 1

Dither 2

Dither 3

User’s Guide →

11

Dither 0 Dither 1

Dither 2 Dither 3

12

A-5 Minimize Average Error

MINIMIZE AVERAGE ERROR

User’s Guide →

13

Adjusting Brightness

Brightness=64 Brightness=192

Brightness=128

14

Adjusting Contrast

Contrast=64 Contrast=192

Contrast=128

15

A-6 Random Dither See also A-5 for “Adjusting Brightness”, “Adjusting Contrast”.

Text Fine (2x2 Solid)

Photo Fine (8x8 Blight)

Text Fine (2x2 Solid) Photo Fine (8x8 B

light)

User’s Guide →

16

Adjusting Outline Detection Threshold

Outline Detection Threshold = 0 Outline Detection Threshold = 127

A-7 Filter

User’s Guide →

17

Emphasis 3x3

Original (Threshold=128)

Average 3x3

Average 3x5