12
colour imaging
is impossible; the camera gathers a lot of information that the spectrometer cannot see. Also, the response of the camera is not uniform, and it is quantified. An eight-bit camera does not have the dynamic range or the resolution of a spectrometer.’
Dealing with data Pierantonio Boriero, product line manager at Matrox Imaging, outlines changes to the ways in which the oldest applications for colour imaging have evolved: ‘It’s fair to say that the printing industry is the sector that has been doing colour analysis for the longest, since the beginning of optical inspection being used in that industry in fact. We’ve been talking to customers in the print industry since the beginning of Matrox. Back then you needed dedicated hardware in order to do the basic colour analysis – you just couldn’t get the throughput with off-the-shelf personal computers. Since then, however, the computational power at the customers’ disposal has increased to the point that most solutions rely purely on software tools.’ Colour imaging is more data-intensive than monochrome data, in part because of the way in which the colour data is captured, as Dalsa’s Ben Dawson explains: ‘Colour cameras usually
use a Bayer pattern (named after Bryce Bayer, who invented the pattern while at Kodak), where tiny, coloured filters are placed over a monochrome sensor to turn it into a colour sensor. This is the typical sensor found in a consumer camera and in most machine vision cameras. The Bayer pattern effectively reduces the sensor resolution by a factor of two in each direction and introduces colour artefacts,’ he says, adding that Dalsa and other suppliers produce algorithms that remove these artefacts. Higher colour resolution and quality can be obtained by using three separate sensors (red, green and blue spectral bands), but most applications, he says, use the lower-cost Bayer pattern cameras. The Bayer pattern means that colour
images contain three times as much data as their monochrome counterparts, and Matrox Imaging’s Lina believes that the difficulties of processing this data may have deterred customers from using a colour imaging solution in the past. ‘I think that the price of a colour camera five years ago and the speed and the power of the available PCs was definitely a limiting factor when deciding whether to go with a colour system, but this is not the case any more. With the multicore CPUs and multi-CPU machines that we have today, the
cost of computing power is much lower.’ Boriero adds that the increased computing power made available by the relatively new field of GPU-acceleration will be useful to colour imaging customers, as will the new breed of GPUs integrated directly into CPUs (the Sandy Bridge architecture from Intel and the APU architecture from AMD). Computing power, however, is no longer
an obstacle to the adoption of colour imaging, but Boriero notes that many applications are yet to make full use of colour imaging, or are using it for unusual reasons. ‘There are quite a few customers who actually integrate colour cameras into their systems, solely for the purpose of producing a colour image for the operator, even though the image processing is all being done in the background in monochrome,’ he says. The challenge, he says, is making sure that the customers understand the capabilities of modern colour imaging.
Further inFormation
l Dalsa:
www.dalsa.com l Basler Vision Technologies:
www.baslerweb.com
l Matrox Imaging:
www.matrox.com/imaging
Always in focus.
Always reliable. Infrared-corrected lenses with 5 megapixels from Fujinon.
www.fujinon.de
High resolution of 5 megapixels and infrared correction – Fujinon combines both of these features in the new
HF35SR4A-1 and HF50SR4A-1 lenses with 35 and 50 mm focal length. As with all machine vision lenses from Fujinon the fixed focal lengths for 2/3" have low distortion values (-0.04% and +0.06% respectively) and minimum chromatic
Medical TV CCTV Machine Vision
Binoculars
aberration. The lenses are not only designed for machine vision but can also be used in various applications for example number plate recognition in traffic monitoring situations. The high resolution and infrared correction ensure sharp pictures down to the smallest detail both for applications in the visible spec- trum and also under IR conditions. Fujinon. To see more is to know more.
FUJINON (EUROPE) GMBH, HALSKESTRASSE 4, 47877 WILLICH, GERMANY, TEL.: +49 (0)2154 924-0, FAX: +49 (0)2154 924-290,
www.fujinon.de,
cctv@fujinon.de
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40