TRULY AUTOMATED LIGHT AND COLOR MEASUREMENT FOR … · SEE THE DIFFERENCE 2 Truly Automated Light...

1 S E E T H E D I F F E R E N C E © 2016 Radiant Vision Systems, LLC. All Rights Reserved. Truly Automated Light and Color Measurement for Tell-Tales and Indicators

TRULY AUTOMATED LIGHT AND COLOR MEASUREMENT FOR TELL-TALES AND INDICATORS

Presented by Shannon Roberts

November 30, 2016


TODAY’S SPEAKER

Shannon Roberts Product Manager, Radiant Vision Systems Shannon Roberts is a Product Manager at Radiant Vision Systems. Having begun her career at Radiant in the role of Applications Engineer, and later Applications Engineering Lead, Shannon has a thorough knowledge of light and color measurement as applied through the use of imaging colorimeters and sophisticated software tools that simplify customer projects. Her understanding of light and color theory has guided customers in defining technical parameters for display and illuminated component inspection in automotive industries and beyond. Shannon received a B.A. in Physics from the University of Colorado, Boulder, and has a passion for improving science education and solving challenging technical problems.


AGENDA

•  About Radiant •  Measuring Tell-Tales and Indicators •  The Trouble with Current Methods •  The Solution: Auto-POI •  Setting Up Automatic Points of Interest •  Addressing Challenges in Manufacturing •  Software Demonstration •  Summary •  Q&A

TODAY’S AGENDA


•  Designs, manufactures, and sells camera-based solutions that simplify sophisticated light and color measurements for R&D and production

•  Has thousands of imaging colorimeters and photometers testing millions of displays and illuminated components in production settings

•  Headquartered in Redmond, WA, USA, with offices in Shanghai, Shenzhen, and Seoul

•  Acquired by Konica Minolta in August 2015

ABOUT RADIANT VISION SYSTEMS


TRULY AUTOMATED LIGHT AND COLOR MEASUREMENT •  Automated Visual Inspection (AVI)

systems are used to measure visual quality of devices quickly and accurately

•  AVI of light and color incorporates an imaging colorimeter and sophisticated software calibrated to human perception

•  This presentation outlines new developments in imaging software that assist instrument cluster manufacturers in the successful integration of AVI for their test and measurement


MEASURING TELL-TALES AND INDICATORS

Requirements and Challenges


MEASURING TELL-TALES AND INDICATORS •  Image of dash with indicators and tell-tales (set

the scene) – possible add a failed value


POINTS OF INTEREST STANDARDS •  Points of Interest (POIs) can

provide average luminance and color values within a region, report out values, and have pass/fail associated for production-level control.

•  Automotive displays include unique arrangements of indicators and tell-tales, and therefore an adaptable method is needed for quality control in real time.


CALCULATING AVERAGE LUMINANCE OF A CHARACTER •  The average luminance of an illuminated indicator can be found using a

large POI to encompass the entire character.

•  Then, employ a threshold to exclude non-illuminated areas.

Average Luminance (No Threshold): 26.6 cd/m^2

No Luminance Threshold:

Average Luminance (10% Threshold): 114.7 cd/m^2

Luminance Threshold:


THE TROUBLE WITH CURRENT METHODS: MANUAL POI •  Manually draw POI around

each symbol to be measured.

•  Time-consuming, especially for complex, multi-symbol displays where symbol position and size may vary.

•  Green rectangles indicate POI boundaries in image.


THE SOLUTION: AUTO-POI

•  New software feature for Radiant ProMetric® or TrueTest™.

•  Draw one area across entire display.

•  Software automatically traces POI around symbols and enables measurement of precise values for symbols and across symbol sets.

•  Green outlines indicate software has located POI (blob) automatically.


THE TROUBLE WITH CURRENT METHODS: STATIC POI •  Static POI are areas drawn in

specific locations relative to the camera Field of View (FOV).

•  Green rectangles indicate static POI boundaries in image.

•  If alignment is not perfect , the static POIs will not capture the character or symbol correctly.


THE SOLUTION: AUTO-POI •  Using Auto-POI, automatic POIs

adjust to any device location in the Field of View of the imager.

•  POIs are created for each image, so perfect alignment is not required.



THE TROUBLE WITH CURRENT METHODS: MULTI-SYMBOL SETS

•  Symbols not adjacent to each other must have uniform light and color across a display.

•  Separate regions of interest must be drawn around each symbol to acquire measurement data.

•  Measurements must be correlated to determine average luminance/ color and uniformity of set (time consuming).

Draw static POI for each symbol and correlate measurements for each symbol set.

All red symbols.


All yellow symbols.







All symbols at once.








•  Using Auto-POI, a single creation region captures all symbols of a given set.

•  Software uses programed luminance and color thresholds to automatically find and measure related symbols.

Single creation region drawn for entire display with automatic POI drawn for symbols based on target color value.

All red symbols.


All yellow symbols.






All symbols at once.






SETTING UP AUTOMATIC POINTS OF INTEREST


SETTING UP AUTOMATIC POINTS OF INTEREST •  Step 0: Take Measurement of Representative Device •  Step 1: Define Creation Region •  Step 2: Set Creation Thresholding Criteria

(Luminance and Color) •  Step 3: Set Pass/Fail Values for POIs to Be Created •  Step 4: Measure Luminance and Color

(POI Are Automatically Drawn) •  Step 5: Report Results


STEP 0: MEASURE DEVICE

•  Capture image of representative device/display using imaging colorimeter •  An imaging colorimeter captures a

wide area to enable measurement across multiple illuminated characters at once


STEP 1: DEFINE CREATION REGION

Creation Region:

•  Rectangle, circle, oval, or polygon

•  Defined areas in the FOV of imaging colorimeter

•  Used as regions to automatically create POIs and assign pass/fail values


User-input thresholds

Search the Creation Region

Pixels above min

threshold

Finds contiguous

pixels

Grouped pixels ! POI

STEP 2: SET CREATION THRESHOLDING CRITERIA

Global Threshold of 30% applied. Only brighter characters found.

.

. Finds

contiguous pixels

Software adapts to variation

Locally adjusts

threshold





Pixels above min

threshold

Finds contiguous

pixels




Global Threshold of 5% applied. Dimmer characters are found, but POI around brighter symbols too large.

.

. Finds

contiguous pixels


Locally adjusts

threshold





Pixels above min

threshold

Finds contiguous

pixels




Global Threshold of 5% applied. Dimmer characters are found, but POI around brighter symbols too large.

Local Thresholding used. All symbols correctly identified.

.

. Finds

contiguous pixels


Locally adjusts

threshold



GLOBAL THRESHOLD: COLOR

•  The user can specify a minimum and maximum CIE x, y (or u’,v’) that the pixel must be between. Only pixels that meet the luminance and color criteria are included in the POI set.

•  Useful when two icons of

similar luminance values, but different colors, are overlapping in the FOV

To create a POI for just the needle, an Auto-POI has been created thresholded to red in the CIE chart

Red needle intersects white “0”.

Luminance only threshold connects characters together in one POI


STEP 3: SET PASS/FAIL VALUES

•  Typical pass/fail types •  Luminance •  Color •  CCT •  STD Dev, Min/Max •  Dominant Wavelength •  Purity •  Min/Max in Region


PASS/FAIL VALUES: COLOR REGION •  Define color region pass/fail criteria

beyond simple minimums and maximum of CIE x,y or CIE u’v’.

•  Tier 1 and Tier 2 suppliers define

regions for any color across a wide variety of instrument clusters and manufacturers.

•  Region Types: •  Rectangle •  Ellipse •  Polygon


PASS/FAIL VALUES: COLOR REGION •  To specify pass/fail values based on

user perceptions of noticeable differences in color, a pass/fail color region in the shape of an ellipse can be used. MacAdam ellipses is one example.

MacAdam ellipses enlarged by a factor of 10 [2]


STEP 4: MEASURE LIGHT/COLOR

•  Run the same inspection against new devices and indicator sets.

•  Saved parameters are applied to appropriate areas, colors, or symbol sets of new display.

•  Can be used to inspect different displays for luminance and color consistency during production-level quality control.

•  Same inspection criteria can be applied to single product or across line changes.

Set #1


STEP 4: MEASURE LIGHT/COLOR

•  Run the same inspection against new devices and indicator sets.

•  Saved parameters are applied to appropriate areas, colors, or symbol sets of new display.

•  Can be used to inspect different displays for luminance and color consistency during production-level quality control.

•  Same inspection criteria can be applied to single product or across line changes.

Set #1 Set #2


STEP 5: REPORT RESULTS

•  Results recorded in software for off-line measurement or in-line pass/fail QA.

•  Depending on software package, measurement results can be saved via: •  Table of values for each POI.

•  Export results report and save.


ADDRESSING CHALLENGES IN MANUFACTURING


CHALLENGES IN MANUFACTURING Problem Solution Measure luminance of multiple points quickly, impossible with spot meter

Imaging Colorimeter and software


MEASURE LUMINANCE OF MULTIPLE POINTS

QUICKLY, IMPOSSIBLE WITH SPOT METER

Spot meter takes single-spot measurements at defined points.

Auto-POI measures entire symbol at once.


Problem Solution Measure luminance of multiple points quickly, impossible with spot meter


Measure absolute luminance and color Imaging Colorimeter and software

CHALLENGES IN MANUFACTURING


MEASURE ABSOLUTE LUMINANCE AND COLOR

Auto-POI applies the same programmed luminance and CIE color tolerances to all displays and devices that are measured.





Fixture tolerances not tight enough to ensure perfect alignment to camera

Adaptable, automatic software solution to find characters in any location



FIXTURE TOLERANCES NOT TIGHT ENOUGH TO ENSURE PERFECT ALIGNMENT TO CAMERA

Auto-POI automatically adjusts to new symbol positions.







Many configurations of displays and instrument clusters; lines change quickly

Adaptable software with pre-set creation regions to find indicators in any location



MANY CONFIGURATIONS OF DISPLAYS AND INSTRUMENT CLUSTERS; LINES CHANGE QUICKLY

Auto-POI automatically adapts to new symbols within same luminance/color tolerance.







Many configurations of displays and instrument clusters; lines change quickly

Adaptable software with pre-set creation regions to find indicators in any location

Need different pass/fail criteria for different color LEDs

Creation regions with Color Thresholding, to create POI and set specific pass/fail for each color LED



NEED DIFFERENT PASS/FAIL CRITERIA FOR DIFFERENT COLOR LEDS

Auto-POI Color Thresholding detects symbols of the same color and applies unique pass/fail parameters

to all symbols of that color.


SUMMARY

•  Auto-POI measures illuminated tell-tales and indicators with imaging colorimeters at increased speed and accuracy of measurement over previous methods.

•  Employs auto-finding techniques, eliminating the need to ensure perfect alignment between imaging colorimeter and sample, or multiple tests for multiple points of interest in a single panel.

•  Indicators measured for various pass/fail criterial including user-defined color regions. •  Both production and R&D applications can benefit from Auto-POI.


THANK YOU! Questions? [email protected]

TRULY AUTOMATED LIGHT AND COLOR MEASUREMENT FOR … · SEE THE DIFFERENCE 2 Truly Automated Light...

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