tracker/nn: Add support for 3x3 pos/size cov matrix (and some cleanup) (#1845)

Adds support for 3x3 covariance matrices for position+size estimation.
My recent (unreleased) models output those instead of only component wise standard deviations.

Overall

    Accept 3x3 covariance matrix output for position+size
    Old models still worked fine in my testing
    Delete commented code which was there previously to support recurrent models. (Won't be used in foreseeable future)
    Delete leftover code for experiments with closed eyes detection (Likewise, I have given up on that / Is not really needed any more)
    Improve comments and code quality in the internal filter code

1 files changed, 4 insertions, 6 deletions

diff --git a/tracker-neuralnet/model_adapters.h b/tracker-neuralnet/model_adapters.h
index 48f2fa2c..c1aaa6de 100644
--- a/tracker-neuralnet/model_adapters.h
+++ b/tracker-neuralnet/model_adapters.h
@@ -50,9 +50,8 @@ class PoseEstimator
             cv::Matx33f rotaxis_cov_tril; // Lower triangular factor of Cholesky decomposition
             cv::Rect2f box;
             cv::Point2f center;
-            cv::Point2f center_stddev;
             float size;
-            float size_stddev;
+            cv::Matx33f center_size_cov_tril; // Lower triangular factor of Cholesky decomposition
         };
 
         PoseEstimator(Ort::MemoryInfo &allocator_info,
@@ -84,16 +83,15 @@ class PoseEstimator
         cv::Vec<float, 4> output_quat_{};   //  Quaternion output
         cv::Vec<float, 4> output_box_{};    // Bounding box output
         cv::Matx33f output_rotaxis_scales_tril_{}; // Lower triangular matrix of LLT factorization of covariance of rotation vector as offset from output quaternion
-        cv::Vec<float, 2> output_eyes_{};
-        cv::Vec<float, 3> output_coord_scales_{};
+        cv::Matx33f output_coord_scales_tril_{}; // Lower triangular factor
+        cv::Vec3f output_coord_scales_std_{}; // Depending on the model, alternatively a 3d vector with standard deviations.
         std::vector<Ort::Value> output_val_; // Tensors to put the model outputs in.
         std::vector<std::string> output_names_; // Refers to the names in the onnx model.
         std::vector<const char *> output_c_names_; // Refers to the C names in the onnx model.
         // More bookkeeping
-        size_t num_recurrent_states_ = 0;
         double last_inference_time_ = 0;
         bool has_uncertainty_ = false;
-        bool has_eye_closed_detection_ = false;
+        bool pos_scale_uncertainty_is_matrix_ = false;
 };