diff options
Diffstat (limited to 'src/modified_gamma_transfer_function.cc')
| -rw-r--r-- | src/modified_gamma_transfer_function.cc | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/src/modified_gamma_transfer_function.cc b/src/modified_gamma_transfer_function.cc index 7878773b..ef4bb225 100644 --- a/src/modified_gamma_transfer_function.cc +++ b/src/modified_gamma_transfer_function.cc @@ -25,8 +25,9 @@ using boost::shared_ptr; using boost::dynamic_pointer_cast; using namespace dcp; -ModifiedGammaTransferFunction::ModifiedGammaTransferFunction (float power, float threshold, float A, float B) - : _power (power) +ModifiedGammaTransferFunction::ModifiedGammaTransferFunction (bool inverse, double power, double threshold, double A, double B) + : TransferFunction (inverse) + , _power (power) , _threshold (threshold) , _A (A) , _B (B) @@ -34,17 +35,29 @@ ModifiedGammaTransferFunction::ModifiedGammaTransferFunction (float power, float } -float * +double * ModifiedGammaTransferFunction::make_lut (int bit_depth) const { int const bit_length = pow (2, bit_depth); - float* lut = new float[int(std::pow(2.0f, bit_depth))]; - for (int i = 0; i < bit_length; ++i) { - float const p = static_cast<float> (i) / (bit_length - 1); - if (p > _threshold) { - lut[i] = pow ((p + _A) / (1 + _A), _power); - } else { - lut[i] = p / _B; + double* lut = new double[int(std::pow(2.0f, bit_depth))]; + if (_inverse) { + double const threshold = _threshold / _B; + for (int i = 0; i < bit_length; ++i) { + double const p = static_cast<double> (i) / (bit_length - 1); + if (p > threshold) { + lut[i] = (1 + _A) * pow (p, 1 / _power) - _A; + } else { + lut[i] = p * _B; + } + } + } else { + for (int i = 0; i < bit_length; ++i) { + double const p = static_cast<double> (i) / (bit_length - 1); + if (p > _threshold) { + lut[i] = pow ((p + _A) / (1 + _A), _power); + } else { + lut[i] = p / _B; + } } } @@ -52,8 +65,12 @@ ModifiedGammaTransferFunction::make_lut (int bit_depth) const } bool -ModifiedGammaTransferFunction::about_equal (shared_ptr<const TransferFunction> other, float epsilon) const +ModifiedGammaTransferFunction::about_equal (shared_ptr<const TransferFunction> other, double epsilon) const { + if (!TransferFunction::about_equal (other, epsilon)) { + return false; + } + shared_ptr<const ModifiedGammaTransferFunction> o = dynamic_pointer_cast<const ModifiedGammaTransferFunction> (other); if (!o) { return false; |