Anders Johannesson, Senior Expert Engineer at Axis Communications provides Smithers Apex with an exclusive into the security imaging market ahead of his presentation at the Image Sensors conference.
Q: Please briefly describe your background and experience in digital imaging.
A: During my almost 30 years in digital imaging I have done many different things. It started in science where I focused on imaging of the Sun. Modern solar imaging is about combining optical instruments such as telescopes, narrow-band filters, spectrographs and polarimeters with digital image sensors and image processing. I worked at solar observatories on the Canary Islands and in
California. I continued to work with imaging within machine vision. This was an interesting experience since suddenly it was possible to control the light on the scene. This luxury is normally not available to astronomers. The next challenge was building cameras. This has taken me from consumer cameras used in mobile phones to security cameras. I joined Axis Communications AB in 2006 and have since focused on security imaging. Here I found many of the challenges from astronomical imaging again, but in new forms.
Q: Security is seen as a significant growth area for digital cameras. What the drivers for this, and how does the market segment in terms of camera type / use?
We have seen a revolution in security imaging during the last 10 years or so. What used to be a market dominated by traditional analog video cameras, with moderate resolution and low flexibility, has become a much more technically advanced. We see much improved image quality, much intelligence within the cameras and advanced systems using IP technology that can solve the imaging tasks in a more efficient way.
The rapid change of the old style cameras has improved imaging dramatically and has enabled many new use cases. Now cameras, for example, implement analytics that can be used to create advanced functionality that goes far beyond traditional security imaging.
Most security cameras are fixed, and even if they contain some means of controlling the position and focus of the camera, the intention is to use this only during installation. A growing number of cameras are moving to provide pan and tilt and they are equipped with motorized zoom lenses. Traditionally outdoor cameras are sitting in protective housings, but lately many cameras are directly designed for outdoor and/or indoor use. Due to total cost of sensor and lens, most cameras use 1/3 inch to 1/2 inch image sensors.
The main resolution has quickly increased from the traditional video resolution into HDTV resolutions, although many higher resolution cameras are available. The first 4k cameras has just been released. Many security cameras have a dome that will protect the camera from dust and vandalism. There is no strict division of the market into different camera types per market segment, but we still see some differentiation. Fixed cameras in domes are for example widely used indoors in retail stores and in similar places, while cameras with larger zoom lenses are more often used outside.
Q: What are the main operational challenges for cameras in security applications, and what is needed from the image sensor technology to address these challenges?
The major challenges within security imaging are related to light and motion. In many cases there is no way to control the illumination of the scene since this would disturb the events. This means that many scenes have a very complex lighting were objects of interest may move in and out of strong light. Fixed cameras will experience quite different lighting conditions during a day or over a year.
The sun might even be in view for some time. Maybe the most challenging scenes are the night scenes where the cameras are struggling with few photons at the same time as objects move and strong light sources, such as headlights and street lamps, are visible. The keyword is identification, so even if the light level is low or the scene has a complex illumination the goal is to identify objects, persons and events with as high accuracy as possible.
Q: Aside from producing high quality images, what other features enabled by sensors are applicable for the security market now and in the future?
Probably the most important ones are heat resistance and durability. A typical security camera sensor is operated 24-7 and thus it is started once and is never shut off; and it might stare right into the sun occasionally during that time. This is a big difference from a sensor used in a consumer camera that is not run all the time. In addition there is a tendency that cameras are put in more and more harsh environments where it is very hot or very cold.
There might also be features in future security camera sensors that will aid the camera in other ways than by providing images. For example in moving cameras, with long zoom lenses, any type of auto-focus support is very welcome.
Q: Finally, we are very pleased to have you on board as a speaker for the conference, please let us know what you are hoping to gain from your participation?
The main goal is to learn from others and to meet old friends in the community. I enjoy going to events with skilled and focused people. As a speaker I always also hope to plant seeds that can grow into ideas that in turn can lead to new technical solutions; in this case hopefully image sensors better suited for use in security cameras.