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# Digitizer Coordinate Adjustment Algorithm

IP.com Disclosure Number: IPCOM000079300D
Original Publication Date: 1973-Jun-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 43K

IBM

## Related People

Holub, EA: AUTHOR [+2]

## Abstract

This algorithm allows digitized circuit pattern data to be adjusted any amount in any direction, at any grid size and scale size, and automatically corrects for linear drawing distortion on both x and/or y axis. It allows almost any circuit design to be digitized. Steps Description Calculation 1 READ input coordinate and SHIFT Coord = Coord * shift value decimal point to denote input coordinate in inches. 2 SUBTRACT scale size from coor- Coord =Coord - scale size dinate (RSl)* to allow linear drawing distortion to be corrected from 1st digitizer coordinate channel, rather than data zero, zero. 3 MULTIPLY zero origin coordinate Coord = Coord * Linear (RS2) by linear distortion error.

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Digitizer Coordinate Adjustment Algorithm

This algorithm allows digitized circuit pattern data to be adjusted any amount in any direction, at any grid size and scale size, and automatically corrects for linear drawing distortion on both x and/or y axis. It allows almost any circuit design to be digitized.

Steps Description Calculation 1 READ input coordinate and SHIFT Coord = Coord * shift value

decimal point to denote input

coordinate in inches.

2 SUBTRACT scale size from coor- Coord =Coord - scale size

dinate (RSl)* to allow linear

drawing distortion to be

corrected from 1st digitizer

coordinate channel, rather

than data zero, zero. 3 MULTIPLY zero origin coordinate Coord = Coord * Linear (RS2) by linear distortion error. distortion

to arrive at corrected coordinate

point. 4 ADD one-half x or y grid dimen- Coord = Coord + Grid sion to scaled coordinate (RS3) Dimension over 2

to arrive at distortion free

half-adjusted coordinate point. 5 ADD scale size back to distortion Coor = Coord + scale size free half-adjusted coordinate

(RS4) to arrive at corrected

true coordinate point. 6 DIVIDE corrected true coordinate Grid Pos = Coord (RS5) by grid size to arrive Grid Dimension

at grid position of corrected

coordinate and drop any

fractional remainder. *Abbreviation of "Result of Step 1"

Steps Description Calculation 7 MULTIPLY grid position (RS6) Coord = Grid Pos * Grid by grid size, to arrive at Dimension

coordinate of center of

channel coordinate falls in

point). 8 DIVIDE grid position of corrected Block = Grid Pos. true coordinate (RS6) by No. of Channels per

channels per block, to arrive at Block

Block No. coordinate falls in and

drop fractional remainder, if any. 9 MULTIPLY Block No. coordinate Block start = Block * falls in (RS8) by channel count Channels per

per block to arrive at 1st grid Block

position of block.

1

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10 SUBTRACT block start grid Channel = Grid

position (RS9) from grid Pos - Block

position of corrected Start + 1

coordinate (RS6) and add one to

result, since channel 1 starts

at grid position phi result is

channel No. coordinate falls in. 11 ADD adjustment for channel No. Coord = Coord + Adj (RS10) and coordina...