Parameter range:

i= 00H (0): Enable halftoning mode A (hard tone): B1 B2 B3 B4 B5 A5

i= 10H (16): Enable halftoning mode B (soft tone): B2 B3 B4 B5 A5

i= 20H (32): Enable halftoning mode C (net-screen): B2 B3 B4 B5

i= 80H (128): Dither mode A (4 x 4 Bayer): B4 B5 A5

 

i= 90H (144): Dither mode B (4 x 4 spiral): B4 B5 A5

 

i= A0H (160): Dither mode C (4 x 4 net screen): B4 B5 A5

 

i= B0H (176): Dither mode D (8 x 4 net screen): B4 B5 A5

 

i= C0H (192): User-defined dither pattern A: B4 B5 A5

 

i= D0H (208): User-defined dither pattern B: B4 B5 A5

 

i= 01H (1): Disable the halftoning process, Disable Text

Enhancement

Technology: B1 B2 B3 B4 B5 A5

 

i= 03H (3): Disable the halftoning process, Enable Text

Enhancement

Technology: B5 A5

 

Default value: i = 00H

 

Explanation:

This command enables or disables the halftoning process modes for bi-level (1 bit per pixel per color) and quad-level

(2 bits per pixel per color) data.

This command also enables or disables Text Enhancement Technology, which optimizes the threshold value and eliminates background noises.

During halftoning mode, the level (on or off) and color of newly read pixels is determined in conjunction with the calculated level and color of surrounding dots that have already been read. This method is designed to interpolate for possible errors during the process of digitizing the image data. In contrast, the dither modes use fixed patterns in a matrix to simulate tonal values.

When the halftoning mode is disabled, the image data becomes plain bi-level or plain quad-level data, according to the data format.

The halftoning process simulates tone differences in an image with bi-level or quad-level data. It is suited for scanning originals with continuous tones, such as photographs. This process is not suited for images without varying tones, such as line art.

3-46Command Reference