Seeing is believing

Image processing has made significant strides over the past few years, as better sensors and cheaper processing power have brought image processing components into the mass-market of consumer products.

Image processing has made significant strides over the past few years, as better sensors and cheaper processing power have brought image processing components into the mass-market of consumer products, such as mobile phones.

This increase, both in the number and diversity of applications, has led to falls in prices per component — and thus good times for manufacturers.

In a recent US survey, 64 per cent of respondents involved in specifying, recommending and/or buying machine vision equipment said they expected to increase expenditure in this area over the next 12 months, up from 35 per cent a year previously.

Earlier in the year a report from business consulting firm Frost and Sullivan noted that such systems are benefiting from greater user-friendliness, easier integration and reduced operator training time as systems themselves become more capable.

Much of the push for superior image sensors comes from the market for domestic devices such as mobile phone cameras. More powerful image sensors are being developed to have high power and low costs and are being released on a frequent basis.

A recent example is Eastman Kodak’s 1.3 megapixel CMOS image sensor, the KAC 01301, which is designed to be used in non-mobile phone applications.

Another company offering such upgraded sensors is Avago Technologies, which has also introduced a 1.3 megapixel CMOS image sensor, the ADCC-3000. Small size, low cost and high power are selling points for these new sensors.

In a similar vein, OmniVision recently introduced its own 1.3 mega-pixel camera chips. Automotive accessories firm Hella uses Omni-Vision sensors in its rear-view cameras, which have an aperture angle of more than 120 degrees and show the driver an image behind the vehicle to enable safe manoeuvering.

Cameras used in machine vision systems have been developing as rapidly as the sensors within them. Industrial Vision Systems’ new NeuroCheck camera series enables users to make application changes in real time as they communicate via an IEEE 1394 (FireWire) bus.

The big advantage of FireWire is not only its speed, but the fact that communications are possible in both directions, enabling software changes to be made to the camera from a control computer.

Ease of use is also improving rapidly. Industrial Vision Systems director Earl Yardley said: ‘More complex functionality is being represented by ever simpler user interfaces. Manufacturers are putting much effort into ergonomic design, to make systems easier to install and use.’

Manufacturers are also addressing the issue of integration. Relationships between companies such as Sony and National Instruments are leading to developments such as the new Sony XSI-SX1 smart camera being compatible with National Instruments’ NI Vision Builder for automated inspection software.

The software comes with a suite of machine vision tools (such as pattern matching, optical character recognition, particle analysis etc), which engineers can configure, removing the need for programming.

Infrared (IR) cameras are following the same trends. For example, Cedip Infrared Systems’ latest IR camera, the Silver 660M, is compatible with standard Windows-driven computers, as well as third-party frame grabbers and other image processing software.

Cedip produces its own Altair image processing software, as well as providing a Labview on C++ driver interface for controlling the camera and processing images on other systems.

Manufacturers are also designing equipment and interfaces for storing records and producing easily traced documentation, especially for the medical and pharmaceutical industries.

For example, in the US, FDA legislation requires companies wishing to sell pharmaceuticals to comply with Good Automated Manufacturing Practices (GAMP); this calls for documentation of every stage of the production process, to ensure the safety of the end user.

Traceability is also important in the manufacture of medical devices, and vision systems are often a good way to automate inspection and associated data handling. In one recent case, Industrial Vision Systems installed a system for the Pfeiffer Company to provide automatic documentation from the examination of pump bodies (similar to those for nasal sprays) with a pumping atomiser.

The pump bodies are mounted on a rotary plate and inspected using two progressive scan cameras. Industrial Vision Systems’ NeuroCheck software evaluates the items and sends information to a PC. Traceability is provided by storing data in in an XML format, allowing all inspection criteria to be easily retrieved.

Medical devices are also subject to draconian legislation before they are accepted for use in many markets. Cognex have installed a vision system for French specialist medical devices manufacturer Central Labo, which provides secure identification of biological samples with complete traceability.

The Cognex system was designed to mark very small containers in a way that was readable automatically and to the human eye. A laser marks samples with a data matrix code, which can be read with a Cognex In-Sight 1010 camera and associated software, as well as with an identification that humans can read. The laser marker and code-reader system have improved identification accuracy and traceability of the samples, leading to a very high confidence level in identification.

Another example of laser marking for medical traceability comes from Australia, where Absolute Vision has supplied an image processing system for the Melbourne-based Southern Health Authority.

The company’s updated medical instrument reader, called the Witness, reads data matrix codes as well as directly applied marks (DAMs) on the surfaces of surgical instruments made from a variety of materials, including plastics and metals.

The software’s high accuracy and ease of use have greatly improved instruments’ accuracy and traceability, lowering the risk of cross-contamination in hospitals.

These few examples highlight specific uses for traceability systems. As such systems become cheaper and easier to use, we can expect to see them more and more widely employed.