fix 5e distortion model; add d500_calibration_distortion enum

src/ds/d500/d500-private.cpp

@@ -157,8 +157,8 @@ namespace librealsense
         {
             auto& rgb_coefficients_table = rgb_calib_table.rgb_coefficients_table;
 
-            // checking if the fisheye distortion is needed
-            if (rgb_coefficients_table.distortion_model == RS2_DISTORTION_BROWN_CONRADY)
+            // checking if the fisheye distortion (2 in calibration table) is needed
+            if( rgb_coefficients_table.distortion_model != d500_calibration_distortion::brown_and_fisheye )
                 return;
 
             // matrix with the intrinsics - after they have been adapted to required resolution
@@ -191,13 +191,11 @@ namespace librealsense
             intrinsics.ppy = k_brown.z.y;
             intrinsics.fx = k_brown.x.x;
             intrinsics.fy = k_brown.y.y;
-            intrinsics.model = RS2_DISTORTION_BROWN_CONRADY;
 
             // update values in the distortion params of the calibration table
-            rgb_coefficients_table.distortion_model = RS2_DISTORTION_BROWN_CONRADY;
+            rgb_coefficients_table.distortion_model = d500_calibration_distortion::brown;
 
-            // Since we override the table we need an indication that the table had changed from
-            // outside this function Decided to use a reserve field for that
+            // Since we override the table we need an indication that the table has changed
             if( rgb_coefficients_table.reserved[3] != 0 )
                 throw invalid_value_exception( "reserved field read from RGB distortion model table is expected to be zero" );
 
@@ -231,11 +229,12 @@ namespace librealsense
             intrinsics.height = height;
 
             // For D555e, model will be brown and we need the unrectified intrinsics
-            // We use reserved[3] as a flag here to indicate the full distortion module is not
-            // really brown but we treat it as such because the HW fixes fisheye distortion.
+            // For SC, model will be brown_and_fisheye and we need the rectified
+            // NOTE that update_table_to_correct_fisheye_distortion() changes the model to brown, so we use reserved[3]
+            // as a flag to indicate this happened
             bool use_base_intrinsics
-                = ( table->rgb_coefficients_table.distortion_model == RS2_DISTORTION_BROWN_CONRADY
-                    && table->rgb_coefficients_table.reserved[3] == 0 );
+                = table->rgb_coefficients_table.distortion_model == d500_calibration_distortion::brown
+               && table->rgb_coefficients_table.reserved[3] == 0;
 
             auto rect_params = compute_rect_params_from_resolution(
                 use_base_intrinsics ? table->rgb_coefficients_table.base_instrinsics
@@ -248,7 +247,7 @@ namespace librealsense
             intrinsics.fy = rect_params[1];
             intrinsics.ppx = rect_params[2];
             intrinsics.ppy = rect_params[3];
-            intrinsics.model = table->rgb_coefficients_table.distortion_model;
+            intrinsics.model = RS2_DISTORTION_BROWN_CONRADY;
             std::memcpy( intrinsics.coeffs,
                          table->rgb_coefficients_table.distortion_coeffs,
                          sizeof( intrinsics.coeffs ) );

src/ds/d500/d500-private.h

@@ -107,12 +107,20 @@ namespace librealsense
             float       fy;             /**< Focal length of the image plane, as a multiple of pixel height */
         };
 
+        // These are the possible values for the calibration table 'distortion_model' field
+        enum class d500_calibration_distortion
+        {
+            none = 0,
+            brown = 1,
+            brown_and_fisheye = 2
+        };
+
         struct single_sensor_coef_table
         {
             mini_intrinsics           base_instrinsics;
             uint32_t                  distortion_non_parametric;
-            rs2_distortion            distortion_model;          /**< Distortion model of the image */
-            float                     distortion_coeffs[13];     /**< Distortion coefficients. Order for Brown-Conrady: [k1, k2, p1, p2, k3]. Order for F-Theta Fish-eye: [k1, k2, k3, k4, 0]. Other models are subject to their own interpretations */
+            d500_calibration_distortion distortion_model;
+            float distortion_coeffs[13];  // [k1,k2,p1,p2,k3] for Brown, followed by [k1,k2,k3,k4] with fisheye
             uint8_t                   reserved[4];
             float                     radial_distortion_lut_range_degs;
             float                     radial_distortion_lut_focal_length;