Ready for prime time

It has been 36 years since I last watched a motion picture in three dimensions. That particular motion picture, Andy Warhol's Frankenstein, as most critics would agree, featured the highest camp this side of the Appalachian Trail. Although the movie itself was awful, the 3-D effects that were produced were as I recall rather impressive.

So, when the prospect of watching another motion picture in 3-D arose last month, I was eager to see the progress that had been made in 3-D cinema over the last three decades.

Early one Saturday morning my son and I drove to the nearest 3-D cinema to view Pixar Animation Studio's latest masterwork Up. Duly equipped with digital cinema servers from Doremi Cinema, the state-of-the-art cinema we attended featured more comfortable seats than can be found in the first-class cabin of a Boeing 787 Dreamliner.

Upon entering, every audience member was handed the latest X101 Series 3-D active glasses from Pasadena, CA-based XpanD. Unlike the polarized 3-D glasses of the past, these digital glasses use the company's patented "pi-cell" liquid- crystal cell to deliver alternate right- and left-eye images and thus the perception of depth.
This, the company claims, produces the brightest, flicker-free stereoscopic image possible. Unfortunately, as the company should have mentioned, only the brightest image possible with this particular technology. Because despite the all-digital cinema, the loss of luminance caused by donning the all-digital glasses rendered the image somewhat dark.

Sadly, I must report that, despite the advent of all-digital cinemas, the progress made in 3-D projection technology in the past 30 years has been minimal. However, the advances in computer animation techniques have proved just the opposite, making Up the best motion picture Pixar has ever produced.

Up, up, and away
For those involved in machine vision, the advent of 3-D systems has resulted in a number of different technologies being deployed in an increasingly larger variety of applications. However, rather than advancing the way images are displayed, these technologies use a variety of methods to capture and process 3-D image data.

Using single and multiple camera-based systems, time-of-flight measurement sensors, and structured light-based cameras, system integrators are now deploying these technologies in applications for bin picking, robotic-guidance systems, and depth perception. Last month, many of these different technologies and applications were on show at the International Robots, Vision & Motion Control Show held near Chicago, IL. As well as highlighting these technologies, a system integrator pavilion allowed attendees to interact with system developers who proudly showed what they had accomplished.

Just as the machine-vision industry has evolved to embrace these new technologies, so too has the business of trade publishing. For those of you who could not attend the show, Vision Systems Design magazine decided to enter the motion picture business, producing a number of "shorts" that allowed vendors, system integrators, and manufacturers to broadcast their messages.

Although not quite as well produced, directed, or written as Pixar's Up, these videos do reflect the progress made by automation companies using 3-D technologies. And, rather than pay a $12 fee to view these videos, we have made them freely available on our web site at www.vision-systems.com.

In the coming months we will be adding more of these videos. Then, later this year, our trusty film crew will also be in Stuttgart, Germany, to bring you the latest news from VISION -- the world's largest machine vision and image processing show. We are sure you will find these videos informative and hopefully entertaining.

Although embracing new technology may not be a wise choice in certain consumer industries, it is certainly applicable to boththe machine-vision and publishing fields. And, for those of our readers who might be wondering, our videos can be viewed without the use of 3-D glasses.

Something old, something new

Many years ago, before the advent of personal computers, journalists used typewriters to compose their musings. After an article was typed, it was proof-read and then sent to be typeset on a typesetting machine that produced long strips of type known as galleys.

The galleys were returned to the publishing company, where they were pasted onto boards, photographed, and the negative images stripped into pages along with negative images of any pictures that accompanied the article. These were then sent to the printer, made into forms that consisted of multiple pages, and set on a print drum for final printing.

With the introduction of the personal computer and direct-to-plate printing systems, this process has been automated, making typesetting companies, prepress houses, and film technology obsolete. But the journey from there to here was not as easy as some may think.

For a number of years the typewriter coexisted with the personal computer as users found it difficult, if not impossible, to print labels using dot-matrix printers, for one thing. With the introduction of graphical user interfaces, a plethora of software standards, and hardware products such as laser writers, these problems no longer exist in today's business world.

Unfortunately, the same cannot be said for the machine-vision industry. Like the publishing days of old, the machine-vision industry is replete with products ranging from lighting and illumination sources, cameras, and software that provide single-point solutions for specific machine-vision applications.

While researching this month's article on machine-vision lighting (see "Spanning the Spectrum", Vision Systems Design, June 2009), for example, I discovered a number of companies who have produced LED light sources that claim to replace older products that use halogen lamps. In their literature these manufacturers promote the products' long lifetimes, high luminous intensity, and reduced running costs.

Peaceful coexistence

Take one look at the spectral characteristics of these illumination systems, however, and you realize that the spectral output and linearity (light output vs. light intensity) of LED light sources is far different from those that use halogen lamps. Thus, microscopy users, who have for a number of years used halogen illumination to capture their images, will not obtain comparable images by simply replacing the halogen light source with one based on LED technology.

Before deploying an LED system, the user may need to optically filter the light source in an attempt to spectrally match the light output obtained by the older halogen lamp. Still, increasing the light intensity of the LED source may not provide the same results as the halogen lamp.

System integrators facing these tasks are also challenged in every other aspect of machine vision. Every year, new camera standards are being introduced, each of which offers its own unique benefits. For example, while Camera Link is fast and deterministic, GigE Vision products can extend camera-to-computer distances by up to 100 m.

Once again, the system integrator must determine which camera interface best suits the application, as well as factors such as the type of sensor used, the lens mount options, and the published specifications of the camera.

In developing new systems, of course, the problem of accommodating older technologies may not matter. If a problem can be solved using new products or technologies, then they will obviously be adopted. However, where backward-compatibility with existing installed systems is important, a complete understanding of the specifications of OEM product replacements is especially important.

Indeed, just as the typewriter and dot-matrix peacefully coexisted for a number of years in every publisher's office, so too will older and newer technologies continue to coexist in the next generation of machine-vision systems on the factory floor. This prospect is likely to continue until future hardware and software standards are developed to unify the choice of components for any specific machine-vision application.