Talking about the wide dynamic range （WDR), we have seen it everywhere in security camera's description, but what's wide dynamic range? Today we are going to explain three different wide dynamic range technologies.
Comparison between D-WDR, WDR, BLC
|Difference||Digital WDR||True WDR||BLC (Backlight compensation)|
|Technology||Adjusts the gamma (Y) value to enhance dark areas||Combines long and short exposures into one frame||Increase the level of exposure for the entire image|
|Pros||Good quality image||Best quality image||Object of interest is clear|
|Cons||image may be slightly washed out||may have minor color restoration problem or color dispersion||overexposure in brightly lighted areas|
Wide dynamic range (WDR)
Wide dynamic range technology can allow camera capture good effect pictures even under challenging light conditions. The WDR can maintain proper image brightness and exposure, also the contrast and ensures image clarity. Both analog and digital IP camera offer this function. DB is the value to measure the wide dynamic range. A higher WDR range (for example 120DB), represents camera can catch a greater scale of brightness.
Digital wide dynamic range (D-WDR)
Digital WDR (D-WDR) is a software-based technique that optimizes image quality by adjusting the gamma (γ) value to enhance dark areas. The D-WDR level, which ranges from 1 to 8, should be carefully adjusted according to the lighting conditions in order to minimize possible image deterioration (i.e. the image being washed out).
True WDR (Sensor WDR)
True WDR is a sensor-based technology, camera with this technology can produce images with an extremely wide dynamic range. The WDR image sensor can capture several images with short and long exposures, then combining them into a single frame. True WDR can be adjusted using three pre-set levels (Low/Mid/High) according to the lighting conditions. Proper calibration of WDR level is essential to achieving the best result –setting the WDR level too low may not produce satisfying visibility, while setting the WDR level to high may lead to washed out images.