feat(torch): add inference visualisation at test time

src/backends/torch/torchlib.cc

@@ -2002,6 +2002,7 @@ namespace dd
   {
     APIData ad_res;
     APIData ad_bbox;
+    APIData ad_res_bbox;
     APIData ad_out = ad.getobj("parameters").getobj("output");
     int nclasses = _masked_lm ? inputc.vocab_size() : _nclasses;
 
@@ -2123,6 +2124,60 @@ namespace dd
                     ++stop;
                   }
 
+                // Raw results
+                APIData bad;
+                // predictions
+                auto bboxes_acc = bboxes_tensor.accessor<float, 2>();
+                auto labels_acc = labels_tensor.accessor<int64_t, 1>();
+                auto score_acc = score_tensor.accessor<float, 1>();
+                std::vector<APIData> pred_vad;
+
+                for (int k = 0; k < labels_tensor.size(0); k++)
+                  {
+                    APIData pred_ad;
+                    pred_ad.add("label", labels_acc[k]);
+                    pred_ad.add("prob", static_cast<double>(score_acc[k]));
+                    APIData bbox_ad;
+                    bbox_ad.add("xmin", static_cast<double>(bboxes_acc[k][0]));
+                    bbox_ad.add("ymin", static_cast<double>(bboxes_acc[k][1]));
+                    bbox_ad.add("xmax", static_cast<double>(bboxes_acc[k][2]));
+                    bbox_ad.add("ymax", static_cast<double>(bboxes_acc[k][3]));
+                    pred_ad.add("bbox", bbox_ad);
+                    pred_vad.push_back(pred_ad);
+                  }
+                bad.add("predictions", pred_vad);
+                // targets
+                auto targ_bboxes_acc = targ_bboxes.accessor<float, 2>();
+                auto targ_labels_acc = targ_labels.accessor<int64_t, 1>();
+                std::vector<APIData> targ_vad;
+
+                for (int k = start; k < stop; k++)
+                  {
+                    APIData targ_ad;
+                    targ_ad.add("label", targ_labels_acc[k]);
+                    APIData bbox_ad;
+                    bbox_ad.add("xmin",
+                                static_cast<double>(targ_bboxes_acc[k][0]));
+                    bbox_ad.add("ymin",
+                                static_cast<double>(targ_bboxes_acc[k][1]));
+                    bbox_ad.add("xmax",
+                                static_cast<double>(targ_bboxes_acc[k][2]));
+                    bbox_ad.add("ymax",
+                                static_cast<double>(targ_bboxes_acc[k][3]));
+                    targ_ad.add("bbox", bbox_ad);
+                    targ_vad.push_back(targ_ad);
+                  }
+                bad.add("targets", targ_vad);
+                // pred image
+                std::vector<cv::Mat> img_vec;
+                img_vec.push_back(torch_utils::tensorToImage(
+                    batch.data.at(0).index(
+                        { torch::indexing::Slice(i, i + 1) }),
+                    /* rgb = */ true));
+                bad.add("image", img_vec);
+                ad_res_bbox.add(std::to_string(entry_id), bad);
+
+                // Comparison against ground truth
                 auto vbad = get_bbox_stats(
                     targ_bboxes.index({ torch::indexing::Slice(start, stop) }),
                     targ_labels.index({ torch::indexing::Slice(start, stop) }),
@@ -2303,12 +2358,17 @@ namespace dd
         ad_res.add("bbox", true);
         ad_res.add("pos_count", entry_id);
         ad_res.add("0", ad_bbox);
+        // raw bbox results
+        ad_res.add("raw_bboxes", ad_res_bbox);
       }
     else if (_segmentation)
       ad_res.add("segmentation", true);
     ad_res.add("batch_size",
                entry_id); // here batch_size = tested entries count
     SupervisedOutput::measure(ad_res, ad_out, out, test_id, test_name);
+    SupervisedOutput::create_visuals(
+        ad_res, ad_out, this->_mlmodel._repo + this->_mlmodel._visuals_dir,
+        test_id);
     _module.train();
     return 0;
   }

src/backends/torch/torchutils.cc

@@ -256,7 +256,7 @@ namespace dd
       torch_utils::copy_weights(jit_module, module, device, logger, strict);
     }
 
-    cv::Mat tensorToImage(torch::Tensor tensor)
+    cv::Mat tensorToImage(torch::Tensor tensor, bool rgb)
     {
       // 4 channels: batch size, chan, width, height
       auto dims = tensor.sizes();
@@ -285,6 +285,13 @@ namespace dd
                 }
             }
         }
+
+      // convert to bgr
+      if (rgb)
+        {
+          cv::cvtColor(vals_mat, vals_mat, cv::COLOR_RGB2BGR);
+        }
+
       return vals_mat;
     }
   }

src/backends/torch/torchutils.h

@@ -136,8 +136,9 @@ namespace dd
 
     /** Converts a tensor to a CV image that can be saved on the disk.
      * XXX(louis) this function is currently debug only, and makes strong
-     * assumptions on the input tensor format. */
-    cv::Mat tensorToImage(torch::Tensor tensor);
+     * assumptions on the input tensor format.
+     * \param rgb wether the tensor image is rgb */
+    cv::Mat tensorToImage(torch::Tensor tensor, bool rgb = false);
   }
 }
 #endif

src/mlmodel.h

@@ -181,6 +181,7 @@ namespace dd
     std::string _corresp; /**< file name of the class correspondences (e.g.
                              house / 23) */
     std::string _best_model_filename = "/best_model.txt";
+    std::string _visuals_dir = "/visuals";
 
 #ifdef USE_SIMSEARCH
 #ifdef USE_ANNOY

src/supervisedoutputconnector.h

@@ -23,6 +23,8 @@
 #define SUPERVISEDOUTPUTCONNECTOR_H
 #define TS_METRICS_EPSILON 1E-2
 
+#include <opencv2/opencv.hpp>
+
 #include "dto/output_connector.hpp"
 
 template <typename T>
@@ -1373,6 +1375,62 @@ namespace dd
       ad_out.add("measure", meas_obj);
     }
 
+    /** Create visuals from test results and write them in the model
+     * repository. */
+    static void create_visuals(const APIData &ad_res, APIData &ad_out,
+                               const std::string &visuals_folder, int test_id)
+    {
+      (void)ad_out;
+      int iteration = static_cast<int>(ad_res.get("iteration").get<double>());
+      bool bbox = ad_res.has("bbox") && ad_res.get("bbox").get<bool>();
+      std::string targ_dest_folder
+          = visuals_folder + "/target/test" + std::to_string(test_id);
+      std::string dest_folder = visuals_folder + "/iteration"
+                                + std::to_string(iteration) + "/test"
+                                + std::to_string(test_id);
+      fileops::create_dir(dest_folder, 0755);
+
+      cv::Scalar colors[]
+          = { { 255, 0, 0 },     { 0, 255, 0 },     { 0, 0, 255 },
+              { 0, 255, 255 },   { 255, 0, 255 },   { 255, 255, 0 },
+              { 255, 127, 127 }, { 127, 255, 127 }, { 127, 127, 255 } };
+      int ncolors = sizeof(colors) / sizeof(cv::Scalar);
+
+      if (bbox)
+        {
+          APIData images_data = ad_res.getobj("raw_bboxes");
+
+          for (size_t i = 0; i < images_data.size(); ++i)
+            {
+              APIData bad = images_data.getobj(std::to_string(i));
+              cv::Mat img = bad.get("image").get<std::vector<cv::Mat>>().at(0);
+
+              // pred
+              std::vector<APIData> preds = bad.getv("predictions");
+              for (size_t k = 0; k < preds.size(); ++k)
+                {
+                  APIData &pred_ad = preds[k];
+                  // float score = pred_ad.get("prob").get<float>();
+                  int64_t label = pred_ad.get("label").get<int64_t>();
+                  APIData bbox = pred_ad.getobj("bbox");
+                  int xmin = static_cast<int>(bbox.get("xmin").get<double>());
+                  int ymin = static_cast<int>(bbox.get("ymin").get<double>());
+                  int xmax = static_cast<int>(bbox.get("xmax").get<double>());
+                  int ymax = static_cast<int>(bbox.get("ymax").get<double>());
+
+                  auto &color = colors[label % ncolors];
+                  cv::rectangle(img, cv::Point{ xmin, ymin },
+                                cv::Point{ xmax, ymax }, color, 3);
+                }
+
+              // write image
+              std::string out_img_path
+                  = dest_folder + "/image" + std::to_string(i) + ".jpg";
+              cv::imwrite(out_img_path, img);
+            }
+        }
+    }
+
     static void
     timeSeriesMetrics(const APIData &ad, const int timeseries,
                       std::vector<double> &mape, std::vector<double> &smape,