Add author info replication script in gatys_ecker_betghe_2016 (#296)

* Add author info replication script

* lint

* Update comment and remove impl_param in nst() function

replication/gatys_ecker_bethge_2016/main.py

@@ -117,6 +117,67 @@ def figure_3(args):
         )
 
 
+def figure_2_author_information(args):
+    images = paper.images()
+    images.download(args.image_source_dir)
+
+    # Gatys provided this information
+    # compute layer_weights and use relu output -> impl_params=True
+    hyper_parameters = paper.hyper_parameters(impl_params=True)
+
+    hyper_parameters.nst.num_steps = 2000
+    hyper_parameters.nst.starting_point = "random"
+
+    content_image = images["neckarfront"].read(
+        size=hyper_parameters.nst.image_size, device=args.device
+    )
+
+    class StyleImage:
+        def __init__(self, label, image, weight_ratio):
+            self.label = label
+            self.image = image.read(
+                size=hyper_parameters.nst.image_size, device=args.device
+            )
+            self.weight_ratio = weight_ratio
+
+    style_images = (  # weight ratio from paper
+        StyleImage("B", images["shipwreck"], 1e-3),
+        StyleImage("C", images["starry_night"], 8e-4),
+        StyleImage("D", images["the_scream"], 5e-3),
+        StyleImage("E", images["femme_nue_assise"], 5e-4),
+        StyleImage("F", images["composition_vii"], 5e-4),
+    )
+
+    for style_image in style_images:
+        print(f"Replicating Figure 2 {style_image.label} with author information")
+        # The weight ratio from the paper is between a larger and a smaller value,
+        # according to the author the larger value was one of the discrete values 1e6 or
+        # 1e9 (1e9  leads to a Runtime Error)
+        larger_value = 1e6
+        hyper_parameters.style_loss.score_weight = larger_value
+        hyper_parameters.content_loss.score_weight = (
+            style_image.weight_ratio * larger_value
+        )
+
+        output_image = paper.nst(
+            content_image,
+            style_image.image,
+            hyper_parameters=hyper_parameters,
+        )
+
+        filename = utils.make_output_filename(
+            "gatys_ecker_betghe_2016",
+            "fig_2",
+            style_image.label,
+            "author",
+            impl_params=args.impl_params,
+        )
+        save_result(
+            output_image,
+            path.join(args.image_results_dir, filename),
+        )
+
+
 def parse_input():
     # TODO: write CLI
     image_source_dir = None
@@ -154,3 +215,4 @@ def process_dir(dir):
 
     figure_2(args)
     figure_3(args)
+    figure_2_author_information(args)