Add a multiply by a Bradford matrix to rgb->xyz conversion.

diff --git a/src/rgb_xyz.cc b/src/rgb_xyz.cc
index 40949f07ebff631d59a1d96a93437b875b0fbec7..bd01b8005171f13a239ea3bb05ab7dea22b13cfc 100644 (file)
--- a/src/rgb_xyz.cc
+++ b/src/rgb_xyz.cc
@@ -103,7 +103,10 @@ libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const LUT>
  *  i.e. AV_PIX_FMT_RGB48LE.
  */
 shared_ptr<libdcp::XYZFrame>
-libdcp::rgb_to_xyz (shared_ptr<const Image> rgb, shared_ptr<const LUT> lut_in, shared_ptr<const LUT> lut_out, double const colour_matrix[3][3])
+libdcp::rgb_to_xyz (
+       shared_ptr<const Image> rgb, shared_ptr<const LUT> lut_in, shared_ptr<const LUT> lut_out,
+       double const rgb_to_xyz[3][3], double const bradford[3][3]
+       )
 {
        assert (lut_in->bit_depth() == 12);
        assert (lut_out->bit_depth() == 16);
@@ -118,6 +121,10 @@ libdcp::rgb_to_xyz (shared_ptr<const Image> rgb, shared_ptr<const LUT> lut_in, s
                double x, y, z;
        } d;
 
+       struct {
+               double x, y, z;
+       } e;
+
        int jn = 0;
        for (int y = 0; y < rgb->size().height; ++y) {
                uint16_t* p = reinterpret_cast<uint16_t *> (rgb->data()[0] + y * rgb->stride()[0]);
@@ -129,31 +136,44 @@ libdcp::rgb_to_xyz (shared_ptr<const Image> rgb, shared_ptr<const LUT> lut_in, s
                        s.b = lut_in->lut()[*p++ >> 4];
                        
                        /* RGB to XYZ Matrix */
-                       d.x = ((s.r * colour_matrix[0][0]) +
-                              (s.g * colour_matrix[0][1]) +
-                              (s.b * colour_matrix[0][2]));
+                       d.x = ((s.r * rgb_to_xyz[0][0]) +
+                              (s.g * rgb_to_xyz[0][1]) +
+                              (s.b * rgb_to_xyz[0][2]));
                        
-                       d.y = ((s.r * colour_matrix[1][0]) +
-                              (s.g * colour_matrix[1][1]) +
-                              (s.b * colour_matrix[1][2]));
+                       d.y = ((s.r * rgb_to_xyz[1][0]) +
+                              (s.g * rgb_to_xyz[1][1]) +
+                              (s.b * rgb_to_xyz[1][2]));
                        
-                       d.z = ((s.r * colour_matrix[2][0]) +
-                              (s.g * colour_matrix[2][1]) +
-                              (s.b * colour_matrix[2][2]));
+                       d.z = ((s.r * rgb_to_xyz[2][0]) +
+                              (s.g * rgb_to_xyz[2][1]) +
+                              (s.b * rgb_to_xyz[2][2]));
+
+                       /* Bradford matrix */
+                       e.x = ((d.x * bradford[0][0]) +
+                              (d.y * bradford[0][1]) +
+                              (d.z * bradford[0][2]));
+
+                       e.y = ((d.x * bradford[1][0]) +
+                              (d.y * bradford[1][1]) +
+                              (d.z * bradford[1][2]));
+
+                       e.z = ((d.x * bradford[2][0]) +
+                              (d.y * bradford[2][1]) +
+                              (d.z * bradford[2][2]));
                        
                        /* DCI companding */
-                       d.x = d.x * DCI_COEFFICIENT * 65535;
-                       d.y = d.y * DCI_COEFFICIENT * 65535;
-                       d.z = d.z * DCI_COEFFICIENT * 65535;
+                       e.x = e.x * DCI_COEFFICIENT * 65535;
+                       e.y = e.y * DCI_COEFFICIENT * 65535;
+                       e.z = e.z * DCI_COEFFICIENT * 65535;
 
-                       assert (d.x >= 0 && d.x < 65536);
-                       assert (d.y >= 0 && d.y < 65536);
-                       assert (d.z >= 0 && d.z < 65536);
+                       assert (e.x >= 0 && e.x < 65536);
+                       assert (e.y >= 0 && e.y < 65536);
+                       assert (e.z >= 0 && e.z < 65536);
                        
                        /* Out gamma LUT */
-                       xyz->data(0)[jn] = lut_out->lut()[(int) d.x] * 4096;
-                       xyz->data(1)[jn] = lut_out->lut()[(int) d.y] * 4096;
-                       xyz->data(2)[jn] = lut_out->lut()[(int) d.z] * 4096;
+                       xyz->data(0)[jn] = lut_out->lut()[(int) e.x] * 4096;
+                       xyz->data(1)[jn] = lut_out->lut()[(int) e.y] * 4096;
+                       xyz->data(2)[jn] = lut_out->lut()[(int) e.z] * 4096;
 
                        ++jn;
                }

diff --git a/src/rgb_xyz.h b/src/rgb_xyz.h
index 734401dcfab58c97fe0e43457f61b00cba574e5c..690ba08ea95d9377f56f868b9806669c6ebc41b8 100644 (file)
--- a/src/rgb_xyz.h
+++ b/src/rgb_xyz.h
@@ -31,7 +31,8 @@ extern boost::shared_ptr<ARGBFrame> xyz_to_rgb (
        );
 
 extern boost::shared_ptr<XYZFrame> rgb_to_xyz (
-       boost::shared_ptr<const Image>, boost::shared_ptr<const LUT>, boost::shared_ptr<const LUT>, double const colour_matrix[3][3]
+       boost::shared_ptr<const Image>, boost::shared_ptr<const LUT>, boost::shared_ptr<const LUT>,
+       double const rgb_to_xyz[3][3], double const bradford[3][3]
        );
 
 extern boost::shared_ptr<XYZFrame> xyz_to_xyz (boost::shared_ptr<const Image>);