Find the most suitable technology for 'safe city' video surveillance

In this article, Dallmeier addresses the issues and challenges that public officials face when selecting the most appropriate technology to implement a video surveillance solution in the city.

The implementation of modern video technology in public spaces is gaining more and more followers. However, In many cases it remains the first project of its kind for public officials, and it is often a complex task. Many elements need to be coordinated and expertise quickly acquired.

This includes decision-making, Authorization procedures, Public Discourse, Planning, the identification of synergies and, finally, but no less important, Selecting the Right Technology for a City Surveillance Project. This article aims to provide useful information on the latter aspect.

No local politician would want a situation like the one that, For example, took place in Cologne on New Year's Eve of 2015. After terrible riots with several hundred people involved, more than 1.200 Charges for, among other things, disturbing public order, Violence and sexual assault.

The fact that there had only been 46 judicial cases and only 33 convictions were due, among other reasons, that the image quality of the recordings of the antiquated video system did not allow any evidence to be provided. Or the perpetrators could not be identified due to lack of resolution, even if the course of the criminal event was clearly recognizable; or the possible perpetrators were easily recognizable, But the small image sections of many individual cameras often did not allow events to be reconstructed in wider optical contexts, so it was not possible to prove involvement in the crime without a doubt.

Image quality, Overview, cost

From these and other experiences gained over many years of video surveillance in public spaces, three key requirements can be deduced: The first is the coverage of large areas with minimal image quality that is as uniform as possible across the entire object space.

The second point is the recognition of contexts: must be able to capture as much of the monitored space as possible in a single image or, In other words,, The number of cameras used should be as small as possible.

Finally,, The third point is, Of course, The cost: The two central criteria – image quality and recognition of large contexts- they must be feasible at reasonable overall costs.

What Minimum Resolution Means and Its Relevance

But how do you actually define image quality for monitoring large areas?? The decisive factor for quality is the resolution required.

This is what is called resolution density or pixel density, as defined in DIN EN 62676-4. The unit pixels per meter indicates how many pixels are available to represent a meter of reality.

In the field of urban surveillance, but also, For example, in sports facilities, A resolution density of 250 px/m (Identify according to DIN EN standard 62676-4) or higher so that the images can be reliably used in court. In other words,, This is the value with which a judge can say with a high degree of probability that the person sitting in front of him and the person in the video image are the same or not. This should be possible even in low light conditions. Since this value must be applied in a generalized way and must not fall below a certain minimum value, Also called minimum resolution density.

How many chambers cover how many m2?

Once this resolution density has been determined for the entire area to be monitored, The camera requirements can be inferred through pre-planning in cooperation with the manufacturer.

Good planning simulates the entire environment as accurately as possible like a digital twin and allows decision-makers to see and evaluate the exact coverage of pixel density and camera views for all areas. This allows for planning that ensures both the fulfilment of the purpose of surveillance – as required by, For example, the EU GDPR- as efficient operation, as well as maximum profitability.

Particularly suitable for meeting these requirements, These are so-called multifocal sensor camera systems that combine images from up to seven detail sensors and one overview sensor into one optical unit.

Individual images are combined using software to form an overall picture, which allows very broad contexts to be represented. This approach combines three distinct advantages. The former, a much smaller total number of cameras, helps to reduce the total cost of ownership, as considerably less infrastructure is needed and fewer operators can cover the same area.

The second advantage is a better overview. As the image is a combination of up to eight individual images, Operators can see the entire scene in a much larger optical context.

And very important, The image is always available in high resolution, both live and in the recording. Live operators and forensic analysts can zoom in on this big picture indefinitely and see any details in high resolution.

City Surveillance and AI

The possibilities – but also the limitations- of video analysis in urban surveillance are multiple and, therefore, are not the subject of this article. However, There is a principle worth keeping in mind for every decision-maker to take into account: Analytics technology is evolving rapidly, and it is wise to stay on top of and observe developments from different analytics specialists.

When selecting camera systems, attention should be paid to the highest and most consistent image quality possible over the entire object space. After all,, The quality of the analysis results can only be as good as the quality of the input data: Quality that enters, sale quality. With the right technology, It will also be well equipped for any future analysis application.

How much does one of those cameras cost??

Unfortunately, Manufacturers or installers are still very often faced with the question of costs per chamber in consulting conversations or in tenders.

Decision-makers should consider modern video security systems as complete solutions, made up of various components such as cameras, Software, Recording Systems, Services and operating expenses. Given the nature of video technology, There are significant differences between the available technologies in terms of operating efficiency, infrastructure costs or even the effort required for installation and deployment.

A closer look

It is always advisable to take a close look at the total costs (Total cost of ownership), that take into account all aspects of the cost of a solution, from initial planning to ongoing operation. Decision-makers should pay particular attention to ensuring that all lots involved in a project are considered together.

In many tenders, Lots for the video system and lots for the necessary building and infrastructure measurements are put out to tender separately. In certain circumstances, This can result in a significant distortion of total costs, For example, if the cameras are cheaper to acquire, but the infrastructure and installation costs required for them are significantly higher than in a comparative offer.

This frequently occurs when it comes to mounting points such as masts, wired, excavations or other construction activities. In the end, The principle of the cheapest and not the cheapest offer also applies to public tenders.

If all this is taken into account, The first urban surveillance project will also benefit municipal and police officials, and will result in greater security for citizens with maximum profitability.

Cost Factors in City Surveillance

When calculating the total cost of a video technology solution, There are many more factors involved than the sheer cost of technical video components: Cameras, Recording and Software.

Decision-makers would do well to calculate accurately and take into account as many cost factors as possible:

• Advice: How much time does it consume? Free or already subject to cost?
• The exact image quality requirements: What is the minimum resolution density required and for which areas? 125 px/m? 250 px/m?
• The number of cameras: How many cameras and of what type are needed for how many square meters of surface area??
• Planning: How long does planning take? What digital systems will be used? This has a direct impact on the speed of implementation and also on flexibility.
• Infrastructure costs, including labor: Are poles required, civil engineering, wired, Network Technology?
• The cost of installation: Here, naturally, The total number of cameras needed plays a key role.
• Mounting systems: Are there systems that make installation particularly expensive or cheaper??
• Configuration documents: To what extent can planning data be used directly during on-site installation?? Some manufacturers can generate installation documents directly from the planning.
• The costs of the technical components themselves: How much do cameras cost, recording systems or software components?
• The costs of ongoing maintenance: What about warranties or support contracts “All inclusive”?
• Operating costs: What are the labour costs of operators?? How many operators are needed for which solution??
• The cost of "unproductivity": How Operator-Friendly Are the Solutions? How many camera images does each operator have to monitor? (A maximum of 6-8 Images by operator)? On the contrary: How many person hours does the respective solution require for active video observation??

Reflections on privacy

In many urban surveillance projects, over and over again, Data protection commissioners are perceived as opponents and kept out of the decision-making process for a lifetime. (Too much) time for fear of possible resistance. However, Often the opposite is true: the sooner the data protection officers are involved – ideally already in the planning phase- the more positive the reaction is usually and the supposed adversary usually becomes a supporter.

often, Categorical rejection is simply due to uncertainty and lack of knowledge. If the interests are taken seriously and those involved are informed at an early stage, For example, involving one or more manufacturers, Understanding and transparency can be increased. A live demonstration of a test facility of the future system – for example, at the City Hall, at a citizen meeting or at an informative event- is usually of great help.

In some countries, as Germany, Video devices in public places must be visibly disabled for participants in legal gatherings. This can be done in a traditional and elaborate way – with very high costs- using lifting platforms and covering them, For example, with cloth bags. But there are also remotely controllable solutions that allow the incident manager to visibly disable the recording with just a few clicks of the mouse.. And, especially, Systems can be reactivated just as quickly if the situation changes.

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