IBM CF Series manual K Ip Averager Lut

5.1.20(K) IP AVERAGER LUT

The image processor board contains a set of lookup tables used for thresholding of image data. There are 256 tables (numbered 00-FF hex) containing 256 bytes each. Only one table is used at a time. The table used is determined by the Threshold, Filter and Tracking settings selected by the operator. The input to the table is the local area average (40 x 40 pixels) of the neighborhood of the pixel under consideration. The output from the table is a threshold value. If the pixel under consideration is less than the threshold, it is classified as a mark. Otherwise, it is classified as media.

<T> Select Table

Enter a hex table number in the range 00-FF. The contents of the table will be displayed on the screen. Only one table can be viewed at a time.

<D> Loads default contents into all tables.

Tables used for absolute thresholding contain the same value in all locations. Tables used for local area thresholding contain an ascending pattern.

<A> Ascending

Writes the pattern 00,01,02,...FE,FF into the selected table.

<U> Uniform

Enter a hex number in the range 00-FF. This number will be written into all locations of the selected table.

<Z> Clear

Zero is written into all locatons of the selected table.

<S> Set Low Limit

Enter a hex number in the range 00-FF. This number is used by the scanner when calculating the tables used for local area thresholding. Table values lower than the low limit are replaced by the low limit. Setting a low limit may be necessary to prevent unwanted removal of marks from a scanned image when Tracking is on. The value set here may be saved in NVRAM ( see section 5.2 ) .

<X> Exit

Exits to the Diagnostic Tests Menu.