Capturing consistent clear imagary is a challenge. Many cameras struggle when handling variations in lighting or reflection. Lighting and reflections are a big cause of disruption in CCTV footage. Lower-quality footage occurs when light is cast directly onto the camera. Additionally, vehicles, water and windows will all cause complications due to reflections. Is your business facing these issues? A wide dynamic range is the answer to your problem.
What Is Wide Dynamic Range?
Wide dynamic range works by improving the visibility of camera footage by balancing any harsh varying lighting. Mentioned previously, standard, non-WDR cameras have faced this issue for a long time. As pictured, ‘WDR img.1’, demonstrates the key difference between ‘WDR ON‘ and ‘WDR OFF‘. Once wide dynamic range is ‘ON‘, the vehicle, the person and the street become visible.
WDR img.1
How Does Wide Dynamic Range Work?
Used in CCTV surveillance, wide dynamic range works by allocating the perfect exposure. Exposure is assigned based on the lightest and darkest areas of the image. The flexibility of wide dynamic range means this CCTV is capable of handling harsh inconsistent lighting. Unlike a standard camera, greater detail is generated when using WDR. Companies seeking natural colour, high quality, lower image noise and more flexibility should opt for wide dynamic range. Important to note, lower image noise directly correlates to smaller image files.
- The lightest and darkest elements of the captured image are analysed by wide dynamic range.
- Once the elements are detected, the camera will measure the ratio between these elements.
- Dark/light shades are then balanced and blended to create a clearer image.
Where Is Wide Dynamic Range Used?
WDR is often used in large, open spaces with a lot of windows. Using WDR means we can capture details that are more difficult for other cameras to capture. Utilising these cameras will improve visibility in poorly lit scenes so you can see small details and colours more accurately.
Wide dynamic range cameras are the perfect solution for those unsure of what they need their CCTV to be capable of.
WDR will combat everyday issues whilst being cost-effective and capable of operating both indoors and outdoors. Capturing images with great detail is made simple with wide dynamic range and ultimately these cameras will slot into any environment with ease.
Due to strong lighting, large windows and inconsistency in light and dark areas, you should use WDR in the following:
Outdoors
Cameras situated outdoors should use wide dynamic range cameras. There are many reasons to use a wide dynamic range camera outdoors.
Firstly, as mentioned previously, this feature allows you to get a better-quality image in areas of high contrast. Typically outdoor areas will be susceptible to high exposure to bright lighting with various reflections and darker shadows cast by objects such as buildings. A wide dynamic range can be useful for capturing finer detail in these areas.
Secondly, a wide dynamic range is also useful in low-light conditions. These conditions will become present during nightfall. Using these cameras will allow you to retain detail in the darker areas of your scene while still maintaining enough light to illuminate any objects that need to be seen clearly by the viewer.
This allows users to get better results in situations where they might normally have been disappointed with their images due to too much light or too little light being reflected off objects due to their surroundings.
Open Spaces
CCTV cameras situated in large open spaces can also benefit from a wide dynamic range. When using none-WDR cameras, it’s not possible to capture a scene exactly as you see it. Traditional cameras are typically not very good at capturing scenes with various lighting exposures.
However, newer WDR cameras make it much easier to overcome some of these limitations. These cameras use multiple images taken at different exposures and combine them into one image that captures all the details in both dark and bright areas of an image. This allows users to get better results in open-area situations with varying light.
WDR is useful as it can take advantage of high-contrast scenes. The WDR feature of the camera corrects for the high contrast and makes for a better-quality image.
Parking Garages
When implementing cameras into parking lots, you should use cameras with a wide dynamic range feature. Wide dynamic range is a feature that produces a clear picture when lots of lighting contrast is present.
When focusing on parking garages, our aim is to capture the detail of those entering, leaving and potentially causing trouble in our parking complex. An above-ground parking complex will typically have large open windows on the outside where natural light can get through. Without a wide dynamic range, it becomes harder to focus on capturing details such as license plates or faces. The natural lighting in the background will produce an entirely different exposure when compared with the lighting inside the complex.
With the introduction of a wide dynamic range sensor for parking areas, you can now have more accurate visuals of what’s happening in your parking lot. Whether it be vehicles or people, this technology will give you a better idea of what’s occurring.
Offices
Cameras situated in offices could really benefit from WDR. In an office, you may want to monitor productivity and employee behaviour. To capture this you will need high levels of detail, especially in larger offices.
Firstly, working in an office building can be a lot of fun, but it can also be stressful. There are lots of moving parts and there are many things that could go wrong at any given time. As a result, it’s crucial to have good security measures in place so you know if someone is trying to break into your office or if your employees get hurt.
Secondly, office buildings with windows and panel lighting will experience contrasting exposure of both lighter and darker areas. Throughout the day the light exposure you can experience in your workplace will vary. A wide dynamic range makes a great choice for your office.
Remember, these are just some of the many ways that WDR technology can be used in an office. It’s a great tool for surveillance applications, but it’s also useful if you have very bright or very dark places inside your building. If you have any questions about our products or services, please contact us today.
Banking
Cameras situated in retail or banking must use WDR. Banks are in need of technology that allows cameras to capture intricate details under varying lighting conditions. This isn’t possible when implementing standard cameras.
Banks are financial institutions that accept large deposits of money on a daily basis. In 2021, the UK suffered financial fraud losses totalling £783.8 million across card payments, remote banking and cheques. CCTV cameras can be set up to monitor both customers and employees interacting at banking teller desks to avoid any fraudulent activities. A wide dynamic range becomes useful when capturing high levels of detail in a variety of different lighting exposures.
In summary, WDR technology is important for banks that need flexibility in lighting conditions. WDR cameras capture details even in low light conditions and can adapt to changing light levels without losing image quality. This makes these cameras ideal for banks that need clear video images at all times of day and night. Also, during periods of high illumination such as when there are nearby street lamps or sunlight streaming through windows into the bank lobby.
Airports
A technique used to balance areas of a CCTV image that are too bright or too dark could benefit an airport greatly. Typically, airports have windows throughout the building meaning there is a lot of natural light exposure. Additionally, airports are subject to high-security threats where individuals and baggage may need to be identified in high levels of detail. A wide dynamic range camera is able to balance these varying light exposures and capture high-quality footage from farther distances than a traditional camera.
Especially useful for monitoring entrances, exits, corridors, security and waiting areas that experience high levels of traffic and movement.
We hope that this section has given you a better understanding of what WDR is and how it can be used to create a more efficient airport surveillance system.
ATM Cash Machines
Cameras that are situated near automated teller machine (ATM) cash points should use wide dynamic range. ATMs are often situated outdoors and have reflective screens, both of which can affect the quality of captured footage.
In addition to this, ATMs can hold up to £200,000 worth of cash meaning they are threatened by thieves and vandals. It is vital to use cameras that are able to capture clear footage from a distance that could be used when presenting evidence when criminal activity occurs.
Not only will cameras see everything that happens in front of the ATM machine, but they also allow businesses to capture more details than normal video surveillance cameras do.
Motorways
Cameras situated on motorways should use a wide dynamic range. The technology used by motorway cameras has advanced enormously in recent years. State-of-the-art cameras are now available on our motorways and they can now cope with high contrasts in lighting. They do this through the use of wide dynamic range. Car windows cause reflections which affect traditional CCTV camera footage. Also, headlights and street lamps can cause a contrast in lighting which again, can affect the traditional CCTV camera.
Schools Cameras situated in schools can benefit from WDR
Click here to view more on CCTV in schools
Technical Terms, Wide Dynamic Range
Wide dynamic range is an accumulation of image sensors and a digital signal processor (DSP). Utilising these components, we can handle a large range of luminance values. Also, combine this with an image processing algorithm and you can increase the clarity across both light and dark areas. Luminance of the captured object is dependent on the reflection and lighting intensity.
Dynamic Contrast
Dynamic contrast refers to the entire spectrum of luminosity. The span of both bright and dark areas in an image. Additionally, the ratio between the largest and smallest value of sound or luminosity is better known as the ‘dynamic range’.
Dynamic contrast utilises tone mapping. Tone mapping drops brightness levels slightly and adjusts tonal values. This is crucial so that we can view the image on digital displays.
Dynamic Capture
Dynamic capture works by increasing the luminosity dynamic range. In quick succession, the camera will take several images at varying exposure levels. Once images are captured, they will be combined to form one image with the ideal exposure to capture the most detail possible.
Additional Information
When WDR is active, usually at 30 frames per second or below, it will capture two varying exposures. The camera can then composite them together. The resulting image is one that can display details from both the dark and light areas of the image.
The process of capturing both exposures works by combining a normal exposure with an underexposed version of the same scene. This means that if you are viewing a very bright outdoor scene, your camera will be able to adjust its settings automatically. This is so that there isn’t too much glare on any surface and everything has enough detail/sharpness.
Use Backlight Compensation When WDR Is Unavailable
When wide dynamic range isn’t an option, you can use backlight compensation (BLC). Backlight compensation (BLC) is a technique used in video systems to allow the camera to compensate for strong backlighting. It is useful in situations where a portion of the subject or camera is moving. Additionally, useful when filming outdoors and experiencing strong sunlight behind the subject.
BLC eliminates areas of total blackness in an otherwise correctly exposed frame. BLC provides more detail in an otherwise dark or silhouetted area.
Conclusion
WDR is a great feature for cameras to have, especially in situations where there are large differences in lighting. It allows you to capture more details with your surveillance system, whether it’s indoors or outdoors. WDR can also be used with other technologies like HDR and tone mapping which help expand the dynamic range of an image even further than what WDR offers alone.
