[experiments] Improve plotter output selection

Fixes #71

beat/cmdline/experiments.py

@@ -36,8 +36,8 @@
 
 import curses
 import glob
-import io
 import logging
+import mimetypes
 import os
 import queue
 import signal
@@ -641,10 +641,6 @@ def plot_impl(configuration, names, remote, show, output_folder):
 
     for exp_name, results in data_to_plot.items():
         for result_name, result_data in results.items():
-            outputimage_name = "{}_{}.png".format(
-                exp_name.replace("/", "_"), result_name
-            )
-
             result_type = result_data["type"]
 
             plotter = _get_plotter_for(result_type)
@@ -660,7 +656,6 @@ def plot_impl(configuration, names, remote, show, output_folder):
                 )
 
             default_parameters = _get_parametters_for(plotter)
-            default_parameters.setdefault("content_type", "image/png")
 
             runner = plotter.runner()
             runner.setup(default_parameters)
@@ -677,18 +672,23 @@ def plot_impl(configuration, names, remote, show, output_folder):
                 sample_data = result_data["value"]
 
             data_to_plot = [("sample_plot", sample_data)]
-            fig = runner.process(data_to_plot)
-            if show:
-                from PIL import Image
-
-                im = Image.open(io.BytesIO(fig))
-                im.show()
+            plotter_data = runner.process(data_to_plot)
 
-            output_name = os.path.join(output_folder, outputimage_name)
-            with open(output_name, "wb") as fh:
-                fh.write(fig)
+            content_type = getattr(runner.obj, "content_type", "image/png")
+            extension = mimetypes.guess_extension(content_type)
+            outputimage_name = "{}_{}{}".format(
+                exp_name.replace("/", "_"), result_name, extension
+            )
+            output_path = os.path.realpath(
+                os.path.join(output_folder, outputimage_name)
+            )
+            with open(output_path, "wb") as fh:
+                fh.write(plotter_data)
                 indentation = 4
-                logger.info("%ssaved image `%s'...", indentation * " ", output_name)
+                logger.info("%ssaved image `%s'...", indentation * " ", output_path)
+
+            if show:
+                click.launch(output_path)
 
 
 def get_dependencies(ctx, asset_name):