Where would you get the information of a person that is detected by the surveillance cameras? and is this applicable in all surveillance cameras or there are only some models that this platform can be used?
You can use almost any kind of camera.
General recommendations for users (tech requirements):The resolution of a captured scene is determined by the camera resolution and the size of the scene.
For example, if you are using a camera that delivers 1280x720 resolution, you can cover a scene that is, at most, 3.0 m wide and maximum distance 6 meters. You will need to select a camera and lens that will allow the field of view to match the scene size at the desired distance between the camera and the scene.
30 pixels is the recommended minimal distance between eyes for a face on image or video stream to perform face template extraction reliably (face detection). 60 pixels or more recommended for better face recognition results. Note that this distance should be native, not achieved by resizing an image.
Face PostureThe face recognition engine has certain tolerance to face posture:
head roll (tilt) – ±25 degrees (configurable);
±15 degrees default value is the fastest setting which is usually sufficient for most near-frontal face images.
head pitch (nod) – ±15 degrees from frontal position.
head yaw (bobble) – ±30 degrees from frontal position (configurable).
±15 degrees default value is the fastest setting which is usually sufficient for most near-frontal face images.
30 degrees difference between a face template in a database and a face image from camera is acceptable.
DistortionMost lenses exhibit distortion. Often this is in the form of barrel distortion. Barrel distortion is caused by lens magnification being smaller on the edges of the field-of-view compared to the center of the image.
The effect is that objects that are near the edge appear closer to the center compared to an undistorted image. Objects of the same size will cover fewer pixels when they are near the edge, compared to what they would cover if they were closer to the center. This means that objects that are near the edge of the field-of-view need to be closer to the camera in order to fulfill requirements on minimum resolution.
The effect of barrel distortion is often much more pronounced at short focal lengths, making wide angle lenses less suited for identification purposes.
IlluminationIllumination greatly affects the ability to identify persons or objects. Shadows, high contrasts and backlit scenes all make identification and recognition more difficult compared to when lighting conditions are more favorable.
Camera features such as wide dynamic range(WDR) and sensors that perform well in low light situations can help, but the best results are obtained if these are combined with additional lightning and adjustment of camera positions to avoid backlit situations.
For identification of a human face, balanced illumination in the region of 200-400 lux is recommended.
MotionIn order to capture sharp footage of fast-moving persons or objects, you will need to use short shutter speeds.
1/50-1/200s shutter speed is recommended (depends on illumination of detected area)
Compression Compression can greatly affect the usability of recorded materials for identification and recognition. High compression ratios will introduce blur or pixelation that makes identification difficult. If the compression algorithm uses a bit rate limit, the compression could increase when motion occurs, making otherwise clear footage unusable. Use highest possible quality compression your camera supports and set high bitrate encoding (>=3072kbps for 1280x720).
IP Camera Internet Connection Speed / Bandwidth RequirementsThe main factors that need to be considered when planning the connection speed / bandwidth requirements of remote recording are:
Video Recording Resolution: 1280x720(720p)
Video Compression/Codec Used: H.264 with best quality compression
FPS: 10-20
Total Bandwidth for 1 camera: 2Mbps(10fps) - 4Mbps(20fps)
Take into account that for customer it's going to be outgoing traffic (maybe it affects on ISP price).