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| author | Sam Hasinoff <hasinoff@google.com> | 2015-06-29 15:30:57 -0700 |
|---|---|---|
| committer | Sam Hasinoff <hasinoff@google.com> | 2015-07-06 13:07:59 -0700 |
| commit | c2094e520c74227750b23d89ec2bd557deef1743 (patch) | |
| tree | 6f38c2e8d073b6ee3ca279eb6631f1bf567c6ee6 /camera | |
| parent | 15c885c961587c4e868a9cf6ef3054042e2975f8 (diff) | |
| download | shamu-c2094e520c74227750b23d89ec2bd557deef1743.tar.gz | |
Improve raw noise model for N6.
Replace the current raw noise model, calibrated using Android's
dng_noise_model.py script, with an improved noise model, using an
updated version of that script.
The new raw noise model has a different parameterization in terms
of ISO:
- The formula for 'S' scales with ISO. While shot noise should
be zero for a completely dark signal, we still include an offset
here to help compensate for black level variations with ISO.
- The new formula for 'O' scales with ISO^2, not ISO. This form is
required because 'O' corresponds to the *variance* due to read
noise. The new formula also treats analog and digital gain
separately. While pre-ADC read noise is affected by both types
of gain, post-ADC read noise is affected *only* by digital gain.
Bug: 16273313
Change-Id: Iec5c7854c1d529b97567235cda9a8041b0ec0914
Diffstat (limited to 'camera')
| -rw-r--r-- | camera/QCamera2/HAL3/QCamera3HWI.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/camera/QCamera2/HAL3/QCamera3HWI.cpp b/camera/QCamera2/HAL3/QCamera3HWI.cpp index 7df3b9a4..940ab3ce 100644 --- a/camera/QCamera2/HAL3/QCamera3HWI.cpp +++ b/camera/QCamera2/HAL3/QCamera3HWI.cpp @@ -5247,8 +5247,8 @@ int32_t QCamera3HardwareInterface::getScalarFormat(int32_t format) *==========================================================================*/ double QCamera3HardwareInterface::computeNoiseModelEntryS(int32_t sens) { - double s = 3.738032e-06 * sens + 3.651935e-04; - return s < 0.0 ? 0.0 : s; + double s = 4.290559e-06 * sens + 4.370087e-05; + return s < 0.0 ? 0.0 : s; } /*=========================================================================== @@ -5264,8 +5264,10 @@ double QCamera3HardwareInterface::computeNoiseModelEntryS(int32_t sens) { *==========================================================================*/ double QCamera3HardwareInterface::computeNoiseModelEntryO(int32_t sens) { - double o = 4.499952e-07 * sens + -2.968624e-04; - return o < 0.0 ? 0.0 : o; + double digital_gain = sens / 320.0; + digital_gain = digital_gain < 1.0 ? 1.0 : digital_gain; + double o = 6.011498e-11 * sens * sens + 2.173219e-06 * digital_gain * digital_gain; + return o < 0.0 ? 0.0 : o; } /*=========================================================================== |