IDL GUI FOR OPTIMIZING COLOR TOLERANCE EQUATIONS Presented

IDL GUI FOR OPTIMIZING COLOR TOLERANCE EQUATIONS Presented By: Rohit A. Patil Instructor: Rolando Raqueño 1

INTRODUCTION o o o Useful for making pass-fail decisions of batches in quality control Typical Industrial practice included a ‘single observer’ making pass-fail judgments of batches. This had many disadvantages: n n Observer not a standard observer ‘Acceptability’ Vs ‘Perceptibility’ o Observer’s tolerance increases 2

SOLUTION o o Use of spectrophotometer Advantages: n n o Judgments based only on ‘perceptibility’ Savings in wages Key requirement: n Optimum color tolerance equation 3

SELECTION OF A COLOR TOLERANCE EQUATION o Options available n n o DEab CIE 94 CIEDE 2000 Derive a new equation (DEopti) Good things about DE 94 and DE 00 n Use of parametric factors 4

THE EQUATIONS o DE 94 ∆E 94 = [(∆L/k. LSL)2+(∆C/k. CSC)2+(∆H/k. HSH)2]1/2 o DE 00 ∆E 94 =[(∆L’/k. LSL)2+(∆C’/k. CSC)2+(∆H’/k. HSH)2+RT(∆C’/k. CSC)(∆H’/k. HSH)]1/2 o DEopti=[C 1+C 2∆L 2+C 3∆a 2+C 4∆b 2+C 5∆a∆b+C 6∆L∆a+C 7∆L∆b]1/2 5

REQUIREMENTS FOR OPTIMIZATION o o Pass-fail visual data around a color standard converted to an interval scale ∆V = loge[f/(1 -f)] ∆V will increase with increase in actual color difference Color tolerance equation fitted to this data using multiple linear regression Closeness of fit given by correlation coefficient 6

THE GUI o Divided into three widgets n n n Starting instruction widget Widget for DE 2000 Widget for optimizing and comparing the equations 7

DE 2000 WIDGET o o Calculate DE 00 for any number of samples around a single standard Save the calculated data in a text file 8

COLOR TOLERANCE WIDGET o o Includes import data buttons Table widgets: n n n o Giving coefficients of optimized equation Giving l, c, h values for DE 94 and DE 00 Giving correlation coefficients of the five equations Slider widget: n Allow user to manipulate the coefficients of optimized equation 9

DATA USED o Pass-fail experiment carried out for Color Measurement Lab-I o Sixteen observers o Took two days to do the calculations 10

FUTURE ENHANCEMENTS o o Tool for analyzing inter-observer variance Add a tool for calculating instrumental wrong decisions 11

LETS LOOK AT THE DEMO! Thank you! 12