Cognex In-Sight Explorer

New Tools for Defect Detection – Hands On

SE06

5 other Cognex Sessions on;

Vision, Bar Code, Checker

Visit Cognex in Booth # 704

See Cognex Gear on the Motion and

Mechatronics Demo in Solution Area #5

Cognex Resources at the Expo

Image Subtraction has been used for a long time to compare images

and find differences (defects) between a “Golden Image” of a good part

and images of a part under inspection. http://homepages.inf.ed.ac.uk/rbf/HIPR2/pixsub.htm

Good Part

Inspected Part

Difference Image

Do Blob Analysis

on Difference Image

Traditional Defect Detection

Image Subtraction

Problems with this technique, all the parts have to be precisely lined up

on top of each other for this too work well.

Cognex’s PatMax software works very well for lining up the images

Allignment errors cause “ghosts” around the edges of the part, Cognex’s

Flexible Flaw Detect Tool removes these from the edges.

Traditional Defect Detection

Image Subtraction

Blob analysis requires a threshold for the entire inspection region.

Blob analysis is unable to handle lighting variations, even gradual ones

over the inspection region.

Blob and Image Subtraction Techniques often have trouble with variation

at the edges of parts, we often have to ignore part edges with these

tools because of edge variation from one part too the next.

Traditional Defect Detection

Blob Analysis

Flexible Flaw Detection Tool (Spreadsheet Only)

Able to detect defects for graphically complex images

Surface Flaw Detection (EasyBuilder and Spreadsheet)

Finds defects in uniform areas

Has a “Mask” function for complex areas, but ignores these areas

Edge Defect Detection (EasyBuilder and Spreadsheet)

Allow Defect Detection at the edges of parts

Find Min and Max Deviation from Line

Find Gaps along a Line

New Tools for Defect Detection

| Confidential © 2013 Cognex Corporation

FlexFlaw Detection (FFD)

Good Part

Bad Part (Logo / Pad Print Defect)

| Confidential © 2013 Cognex Corporation

FlexFlaw Detection (FFD)

Good Part

Bad Part (Logo / Pad Print Defect)

Surface Flaw Modes

Source Image

“Fast” Mode finds edge of defects “Light & Dark” Modes find area of defect

Surface Flaw Example

Application

Part: Rubber Valve

Detect Tears

Detect Holes

InspectEdge

Good Part

Bad Part (Injection Mold Short Shot)

InspectEdge

Good Part

Bad Part (Injection Mold Short Shot)

InspectEdge

Good Part

Bad Part (Injection Mold Short Shot)

Please Open your Lab Manuals

Lab Time: 35 Minutes

5 other Cognex Sessions on;

Vision, Bar Code, Checker

Visit Cognex in Booth # 704

See Cognex Gear on the Motion and

Mechatronics Demo in Solution Area #5

Enjoy the rest of the Expo!

Cognex Resources at the Expo