Why the ture intensity value of DNG out of the range Matlab shows(blacklevel & whitelevel)?

[cgh72028224]

When using Matlab to deal with a DNG picture,it shows that the BlackLevel and WhiteLevel is 2047 and 15000 respectively.

But there still exists a weird phenomenon that the intensity values of some pixels are out of this range (2047-15000), such as 1997, 15297.

Why???

[sandy_mc]

In general, the black level is set with reference to the noise floor of the sensor, so yes, you can have values below that. The white level is generally set to the level at which the sensor/processing chain begins to saturate/become non-linear, so again, you can easily have values above that.