Electronic Imaging Fundamentals: BISCUITS

“..any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clark

July 2008

Background: Quality control is of major importance in the food industry. Inspection of the biscuit by human inspectors prone to short and long term variations.An automated biscuit inspection system using cameras is proposed.

Requirement: Provide image analysis technology linked to a camera to measure biscuit size / thickness / colour / shape and filling.ALARM when measurement obtained is outside SPEC, allowing biscuit to be rejected.

Why do Image Analysis?

Better Definition of Contrasting Areas Improved Precision/Accuracy in Measurements Reproducibility of Results Higher Throughput than Manual Methods

A Word About Our Eyes Eyes are very good contrast adjusters, but

not good for distinguishing subtle variations in color

Eyes can discern about 30 continuous levels of gray or color in a field of view

Eyes are not good judges of distance Eyes cannot accurately reproduce

measurements

Which is BIGGER / LONGER???

Electronic Imaging Fundamentals

AcquireProcessIdentify AnalyzeReport

Arguably, the most important aspect of all Proper setup of imaging apparatus is vital Obtain maximum contrast and dynamic range Reduce “noise” and other unwanted artifacts Uniform lighting (light) Product presentation (right way up) Speed (CCTV VS DIGITAL)

Acquiring the Image

Slide 9

www.I-Cube.co.za

Lens

Image sensor Digitizing Pre-processing

Timing Interface

PLC

Cat-5e Ethernet cable up to 100 m

Local I/Os:- Trigger input- Results output

Illumination control

Image ProcessingIn PC

Illumination

(Lens Iris Video)

Power

Acquire

Calibration

Size (length, width) Colour (filling; biscuit) Combinations of the above

Site visit:2 cameras per lane

1 for filling, 1 for breakages10-15 biscuits per second

10 cm working areaConcern of cream on lens?

Thresholding an Image Select appropriate morphometric characteristics

Identify regions of interest to analyse

Mask regions

ColourSizeShapeIntensity

Damaged Biscuits

Recorded Rejected % allowed % to alarm % to turn off machine

NEXT STEP: 2 Options Option 1: Order System 3 Payment Options:

Capital (+- R 45 000.00 per line) Rental per Month (+-R 8 000.00) Cost per Biscuit (0.08 c)

Option 2: Consulting @ R 7 500.00 to prove above costs