Why don’t my security camera video images look as good on review as they do on the live view?
It’s a common conundrum, and what complicates the answer is that the problem could stem from more than just one factor. In this post, we’ll dig deeper into some of the reasons why your recorded security images may not match the live view feeding from your cameras from a quality/resolution perspective. From equipment and storage issues to even camera settings adjustments, here’s a look at some things that you can do to ensure high-quality security recordings.
Why high-resolution images from the camera do not always provide high-resolution displays or recording
Very crudely the video output of a system is reliant on all elements of the system being of equal resolution capabilities. Any lower resolution equipment will by default affect the video quality from that point (i.e. the overall system capability is limited to the lowest common denominator in the video path).
One simple example of this may be because the recorded video is being reviewed on lower resolution monitors.
Consider this for a moment and it makes sense: If you have a camera that provides a 4K resolution output at 30 images per second and all your equipment is of similar quality, then there should be little image degradation. However, if one factor changes in the core output, then there will be an impact on the video quality, and depending on these factors the change could be either very minor or very significant.
Expanding this theory further and using the example above, if a 4K camera provides an output resolution of 3840 x 2160 at 30 images per second and you view that output on a monitor with a maximum resolution of 1920 x 1080, then the best quality image that can be expected is 1920 x 1080. Therefore, a 1080p HD camera would give you the same image quality assuming you are working with the same 1080p monitor.
This basic analogy works if the input and output remain unchanged but in this example, a digital zoom capability could provide additional information on the monitor due to the higher pixel density making the purchase of the 4K camera a viable option.
The principle of these examples is to show that it can be advantageous to procure the latest technology, but it is essential that you understand the implications and know how the other items of equipment in the system operate to ensure the system expectations can be achieved.
With current technology, CCTV systems are not as straightforward as the example above and consist of complex configurations of equipment, networks, software, compression standards, algorithms and integration which can provide various benefits, features or solutions dependent on the selected products for the end user. The options available also mean that the same item of equipment could provide more features when connected to one product when compared to another, all of which can impact the final result.
With very few exceptions, it is possible to customise the individual products that are configured to provide a CCTV surveillance system. As an example, the fundamental configuration of a camera could consist of:
- The camera resolution selected (Note: All cameras have multiple resolutions selectable below the maximum resolution stated on the specification.)
- The compression standard used
- The compression ratio selected
- Images per second transmitted
- Limits on bandwidth
- Image settings
- Multiple video streams
- Video analytics
Each of these settings could impact the image quality and, if expanded across a complete system, it is easy to see how the final output can be affected.
Similar settings are available for other CCTV equipment, but it is easy to see how adjustments to limit the storage requirement can have an adverse effect on the review of the recording of images.
Please bear in mind that if you read a specification for a new car that states it has a top speed of 150 mph but also states it will also do 50 mpg, most people will appreciate that both results would not be achievable at the same time.
It is therefore critical to develop a specification that clearly defines the required output to ensure that the final result meets the user’s expectations.
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