C++ (Cpp) lab_f_inv_mの例

コード例 #1

ファイル: colorout.c プロジェクト: LViatour/darktable

static inline void _dt_Lab_to_XYZ(const float *const Lab, float *const xyz)
{
  const float d50[] = { 0.9642f, 1.0f, 0.8249f };
  const float coef[] = { 1.0f / 500.0f, 1.0f / 116.0f, -1.0f / 200.0f };
  const float offset = (0.137931034f);

  float _F[3];
  _F[0] = Lab[1];
  _F[1] = Lab[0];
  _F[2] = Lab[2];

  for(int c = 0; c < 3; c++)
  {
    _F[c] *= coef[c];
  }

  float _F1[3];
  _F1[0] = _F[1];
  _F1[1] = 0.0f;
  _F1[2] = _F[1];

  for(int c = 0; c < 3; c++)
  {
    const float f = _F[c] + _F1[c] + offset;
    xyz[c] = d50[c] * lab_f_inv_m(f);
  }
}

コード例 #2

ファイル: colorout.c プロジェクト: jimmy1977/darktable

static inline __m128
dt_Lab_to_XYZ_SSE(const __m128 Lab)
{
  const __m128 d50    = _mm_set_ps(0.0f, 0.8249f, 1.0f, 0.9642f);
  const __m128 coef   = _mm_set_ps(0.0f,-1.0f/200.0f,1.0f/116.0f,1.0f/500.0f);
  const __m128 offset = _mm_set1_ps(0.137931034f);

  // last component ins shuffle taken from 1st component of Lab to make sure it is not nan, so it will become 0.0f in f
  const __m128 f = _mm_mul_ps(_mm_shuffle_ps(Lab,Lab,_MM_SHUFFLE(0,2,0,1)),coef);

  return _mm_mul_ps(d50,lab_f_inv_m(_mm_add_ps(_mm_add_ps(f,_mm_shuffle_ps(f,f,_MM_SHUFFLE(1,1,3,1))),offset)));
}