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To the best of our knowledge, proposed is a novel variable depth of field smart imager design using intelligent laser targeting for high productivity multiple barcodes reading applications. System smartness comes via the use of an Electronically Controlled Variable Focal-Length Lens (ECVFL) to provide an agile pixel (and/or pixel set) within the laser transmitter and optical imaging receiver. The ECVFL in the receiver gives a flexible depth of field that allows clear image capture over a range of barcode locations. Imaging of a 660 nm wavelength laser line illuminated 95-bit one dimensional barcode is experimentally demonstrated via the smart imager for barcode target distances ranging from 10 cm to 54 cm. The smart system captured barcode images are evaluated using a proposed barcode reading algorithm. Experimental results after computer-based post-processing show a nine-fold increase in barcode target distance variation range (i.e., range variation increased from 2.5 cm to 24.5 cm) when compared to a conventional fixed lens imager. Applications for the smart imager include industrial multiple product tracking, marking, and inspection systems.

Optical coherence tomography (OCT), as an interferometric method, has been studied as a distance ranger. As a technology capable of producing high-resolution, depth-resolved images of biological tissue, OCT had been widely used for the application of ophthalmology and has been commercialized in the market today. Enlightened by the emerging research interest in biomedical domain, the applications of OCT in industrial inspection were rejuvenated by a few groups to explore its potential for characterizing new materials, imaging or inspecting industrial parts as a service solution[3]. Benefiting from novel photonics components and devices, the industrial application of the older concepts in OCT can be re-visited with respect to the unique performance and availability. Commercial OCT developers such as Michelson Diagnostics (MDL; Orpington, U.K.) and Thorlabs (Newton, NJ) are actively exploring the application of OCT to industrial applications and they have outlined meaningful path toward the metrology application in emerging industry[3]. In this chapter, we will introduce the fundamental concepts of OCT and discuss its current and potential industrial applications.

We present a polarization-controlled terahertz (THz) wave spectroscopic imaging modality to investigate the anisotropy of the detected materials. The polarization of the emitted THz wave is controlled to be horizontal and vertical by changing the relative phase of the fundamental and second-harmonic waves in the two-color laser-induced air plasma THz generation configuration. The anisotropy of the industrial sprayed-on-foam-insulation (SOFI) is characterized by measuring its azimuthal angle dependent THz polarization response. This work demonstrated that THz wave polarization-controlled imaging technique can be used for highly sensitive industrial inspection and biological related characterization.

Optical tools offer a route to increasing throughput and efficiency in industrial inspection operations, one of the most time-consuming and labour-intensive aspects of modern manufacturing. One prominent example in the medical device industry is inspection of drilled holes, particularly in narrow-bore tubes (precision-flow devices, such as catheters for drug delivery, radio-opaque contrast agents, etc). The products in which these holes feature are increasing in complexity (reduced dimensions, increasing number of drilled features- in some products now reaching into the hundreds). These trends present a number of technical challenges, not least to ensure that holes are completed and that no damage to the part occurs as a result of over-drilling, for example. This paper will present a novel sensor based on back-side illumination of the drilled hole using side-glowing optical fibers to detect, qualify and quantify drilled holes. The concept is based on inserting a laser-coupled side-glowing optical fiber into the lumen of the tube to be drilled, and imaging the light emitted from this fiber through a drilled hole using a vision system mounted external to the tube. The light from the fiber allows rapid determination of hole completion, shape and size, as well as quantity in the case of products with multiple holes. If the fiber is mounted in the tube prior to drilling, the light emitted from the fiber can be used as a real-time hole breakthrough sensor, preventing under or overdrilling of the tube.

Industrial inspection requires very fast and reliable measurements. One of the techniques, recently widely used for monitoring of engineering objects, is digital holographic interferometry (DHI). In the paper we present novel digital holographic cameras (DHC). Their configuration allows to provide high accuracy information about shape, out-of-plane and in-plane displacement distributions, through capture of digital hologram by CCD, numerical reconstruction of phases and their proper manipulation. Digital holographic systems presented have compact design, fibre optics light delivery system and automatic data acquisition and processing. The cameras capture data in real-time and have low sensitivity to environmental changes. In the paper several examples of engineering application of these cameras are presented.

In this paper, we will derive a phenomenological model of the bidirectional reflectance distribution function of non-Lambertian metallic materials typically used in industrial inspection. We will show, how the model can be fitted to measured reflectance values and how the fitted model can be used to determine a suitable illumination position. Together with a given sensor pose, this illumination position can be used to calculate the necessary shutter time, aperture, focus setting and expected gray value to successfully perform a given visual inspection task. The paper concludes with several example inspection tasks.

With the recent technological advances, there is an increasing need for measurement systems providing interferometer resolution for inspection of large quantities of individual samples in manufacturing environments.. Such applications require high measurement rates, robustness, ease of use, and non-contact systems. We show here that Digital Holographic Microscopy (DIM), a new method that implements digitally the principle of holography, is particularly well suited for such industrial applications. With the present computers power and the developments of digital cameras, holograms can be numerically interpreted within a tenth of second to provide simultaneously: the phase information, which reveals object surface with vertical resolution at the nanometer scale along the optical axis, and intensity images, as obtained by conventional optical microscope. The strength of DHM lies in particular on the use of the so-called off-axis configuration, which enables to capture the whole information by a single image acquisition, i.e. typically during a few ten of microseconds. These extremely short acquisition times make DHM systems insensitive to vibrations. These instruments can operate without vibration insulation means, making them a cost effective solution not only for R&D, but also especially for an implementation on production lines. Numerous application examples are presented in this paper such as shape and surface characterization of high aspect ratio micro-optics, surface nanostructures, and surface roughness.

Building of three-dimensional models is an important topic in computer vision. Range finders only let to reconstruct a partial view of the object. However, in most part of applications a full reconstruction is required. Many authors have proposed several techniques to register 3D surfaces from multiple views. In this paper, a survey of the most common techniques is presented. Furthermore experimental results are performed, and a 3D model is obtained.

We propose a novel structured light method, namely trapezoidal phase-shifting method, for 3-D shape measurement. This method uses three patterns coded with phase-shifted, trapezoidal-shaped gray levels. The 3-D information of the object is extracted by direct calculation of an intensity ratio. Theoretical analysis showed that this new method was significantly less sensitive to the defocusing effect of the captured images when compared to the traditional intensity-ratio based methods. This important advantage makes large-depth 3-D shape measurement possible. If compared to the sinusoidal phase-shifting method, the resolution is similar, but the processing speed is at least 4.5 times faster. The feasibility of this method was demonstrated in a previously developed real-time 3-D shape measurement system. The reconstructed 3-D results showed similar quality as those obtained by the sinusoidal phase-shifting method. However, since the processing speed was much faster, we were able to not only acquire the images in real time, but also reconstruct the 3-D shapes in real time (40 fps at a resolution of 532 x 500 pixels). This real-time capability allows us to measure dynamically changing objects, such as human faces. The potential applications of this new method include industrial inspection, reverse engineering, robotic vision, computer graphics, medical diagnosis, etc.

When it was first introduced two years ago, Indigo Systems Corporation's UL3 Alpha, a miniature uncooled infrared camera, set new standards for ultra-low size, weight and power within the thermal imaging industry. Now Omega, the next generation in Indigo's UL3 product line, takes advantage of novel algorithms and packaging concepts to further reduce size, weight, and power while still improving performance. These qualities make Omega an ideal candidate for many commercial and military applications, including fire-fighting, law enforcement, industrial inspection, remote surveillance, miniature unmanned aerial vehicles (UAVs), unmanned ground vehicles (UGV), and numerous other possibilities. This paper describes the design, performance and salient features of the Omega camera. Current and future applications of the UL3 product line are also discussed.

This paper will guide the first-time user toward proper selection and use of IR detectors for applications in industrial inspection, process control, and laser measurements.

Vision systems for color measurement should be designed with the basic principles of colorimetry in mind. A lack of understanding that a vision based color measurement system could fall if it ignores the basic principles of colorimetry is the main reason for some earlier color vision system failures. The purpose of this paper is to clarify how the color measurement principles have to be applied to vision systems and how the electro-optical design features of colorimeters have to be modified in order to implement them for vision systems. Despite their considerable advantages color vision systems are not capable of solving all color and appearance problems. Not understanding the limitations of this new technology is another reason for the slow progress of color vision systems. Sometimes color vision systems have been used for solving problems which, for a variety of reasons cannot be successfully resolved with them. A critical overview of the major areas of applications for color vision systems will be presented.

Rochester, NY 14511ABSTRACTAutostereoscopy is finding acceptance in applications wherestereoscopic imaging is critical and where the use of stereoglasses and virtual reality head mounted displays (HMDs) isunacceptable. A wide variety of telerobotic activities arebeginning to rely on autostereoscopic displays for visual input.Experimental applications have been found in industrial inspectionand sign language learning/communication.Keywords: autostereoscopic, stereoscopic, 3D, display, virtualreality, yR1 telerobotics, industrial inspection, sign language.2. AN AUTOSTEREOSCOpIC VIDEO SYSTEM FOR INDUSTRIAL

In some applications, such as industrial inspection, it is often convenient or necessary to generate a stereo pair of images with a single photographic, X-ray, or video camera. The left and right views are created by moving the objects or the camera. This paper discusses this method of stereo image acquisition, illustrates some pitfalls, and shows how to overcome them. Examples images are presented that have come from applying the methods to the radiographic inspection of armament and tires.

We propose a new technique of AHI which combines the high speed operation advantages of dynamic holographic interferometry and a real- time, high resolution, high stability, Denisyuk's holograms. Based on a new high sensitive phototerfractive reversible crystals group 23 doped (P and Cu) a small power CW laser was used for continuously hologram read and read-out processing. Portable wariant of a small size AHI sensor and practical demonstration of this technique are described.

Recent developments of interferometric techniques for industrial inspection in Japan are reviewed, with special emphasis on automatic fringe analysis, use of unique interferometers, use of advanced devices.

The design of a confocal microscope including a fiber-optic imaging bundle is discussed, and experimental results are presented. The imaging bundle extends the range of the confocal microscope to image samples inaccessible to a conventional confocal system. The main advantage of this design over the single-fiber confocal microscope is the simplified mechanism required in the sample region. Applications of this design include biological research, industrial inspection, and potentially in-vivo medical systems.

A family of high performance industrial laser scanners has been developed at Philips, based on a unique, reflective, field flattening system as an alterative for f-(Theta) scan lenses that are usually applied in laser scanners. This novel scan approach enables pure telecentric and flat field scanning of wide formats at very high resolution and speed. The attractive features of this particular scan concept are demonstrated by two different 2-D industrial inspection problems that have been solved at Philips during the last ten years.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Electronic speckle pattern interferometry (ESPI) is applied to 3-D deformation mapping in practical problems from constructional engineering. The shrinking behavior and bonding ability of repair mortars applied in the restoration of historical stone buildings is monitored. Strategies are illustrated to process the huge amount of deformation data toward parameters characteristic of the relevant processes. Thus, ESPI is extended to routine applications in industrial inspection.

Now that image processing techniques applied to industrial inspection have become well established, vision systems are being used in manufacturing in increasing numbers. This paper examines various approaches to multiple vision systems and introduces the concept of a distributed vision system. This concept is illustrated by describing how a number of compact inspection modules can be connected to a single supervisory computer to form a distributed vision network.

Surface parameterisation using phase measurement of interferometric fringe patterns is supported by a strong theoretical basis. However, little work has been published with regard to the practical implementation of the available methods as tools for industrial inspection. This paper attempts to justify the choice of Fourier Fringe Analysis for this purpose and addresses some aspects of its implementation.

Time delay and integration (TDI) imaging was first applied in the early 1970's to aerial photoreconnaissance as an electronic replacement for photographic film. Since that time, TDI has been applied elsewhere infrequently with bare printed circuit board inspection and document digitizing as the only well-known recent applications. Now, TDI has been effectively brought to bear on an ubiquitous problem, that of inspection of moving webs. Although other imaging techniques have been and are being used for web inspection, none shows the broad adaptability and ease of use of TDI-based imaging. Herein is a review of the TDI technique, a specific implementation of TDI in a unique web-imaging-compatible camera and a comparison of the TDI technique with other current technologies.

Measures of Circularity for Automatic Inspection ApplicationsJ Illingworth and J KittlerSERC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 OQX, UKAbstractMany automatic visual inspection applications involve checking circular holes. In thispaper four circularity measures based on shape compactness, distribution of radius values,distribution of chord lengths between random border points and the Hough transform arecomparatively studied. Properties of the various approaches are investigated over a rangeof image resolutions which are considered to be pertinent to industrial inspection tasks.IntroductionMany automatic visual inspection applications involve checking circular holes. Theparameters that need to be verified include the size, position and circularity of the hole

The image processing of contour type fringe patterns to extract coordinate information is well understood. This paper discusses the further processing of this information in order to determine the fundamental geometrical nature of the underlying surface. Particular reference is made to the use of such analysis techniques for industrial inspection of surface form.

The inspection of centering takes place often in industrial inspection. In this paper, we consider that the two parts can have the sam eor different shape such as rectangle, square, circle, ellipse, regual or irregular polygon.

Product inspection continues to play a growing role in the improvement of quality and reduction of scrap. Recent emphasis on precision measurements and in-process inspection have been a driving force for the development of noncontacting sensors. Noncontacting sensors can provide long term, unattended use due to the lack of sensor wear. Further, in applications where, sensor contact can damage or geometrically change the part to be measured or inspected, noncontacting sensors are the only technical approach available. MTI is involved in the development and sale of noncontacting sensors and custom inspection systems. This paper will review the recent advances in noncontacting sensor development. Machine vision and fiber optics sensor systems are finding a wide variety of industrial inspection applications. This paper will provide detailed examples of several state-of-the-art applications for these noncontacting sensors.

Mapvision is a photogrammetric machine vision system developed by the Technical Research Centre of Finland primarily for industrial inspection and assembly control applications. The system consists of four simultaneously operating solid state cameras and an especially programmed photogrammetric microprocessor. The three-dimensional measuring accuracy is better than 1:5,000. The Mapvision is an automated system enabling for example the dimensional feed-back and interaction between computer aided design and manufacturing phases.

The design of a special purpose configuration recognition system is described brieflyfrom problem statement through specification. The system inspects assemblies for correctpart placement and part type. A variety of uses for such an on -line inspection device aredescribed based on its particular three dimensional measurement capabilities.IntroductionFor the wide variety of industrial inspection needs there is an even wider variety ofcandidate techniques. Very complicated problems may require highly specialized methods.We report here a complex industrial inspection problem and the indicated solution. Followingthat, we seek to describe the general characteristics a problem must have to justify theparticular solution.Some Peculiarities of the Cummins Inspection ProblemThe Cummins Engine Company produces diesel engines. As Figures la,b,c and d canonly begin to show, these engines may differ substantially from one to another. For variousmarket reasons it is not desirable to cut down on the variety of engine options.FIGURE

This paper reviews some of the activity in the UK directed towards realisation and exploitation of practical shop-floor automatic inspection systems. There are still considerable barriers to widespread applications because of the generally specialised nature of each situation, and the complexity and cost associated with achieving satisfactory solutions to image analysis problems. However, rugged solid-state imagers and microprocessor-based signal processing systems are beginning to advance the state-of-the-art to the point at which autonomous and robust equipment of moderate sophistication can be built at reasonable cost. The impact of microelectronics on performance and cost of equipment for inspection applications, and the problems of justifying and maintaining this equipment, are examined. Projects in which Sira Institute has been involved are referred to briefly to illustrate some of the points made.© (1979) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.