Fix incorrect path handling (#731)

* Fix incorrect save dir path handling for ML format.

Save dir path was split by incorrect os.dependent separator '/'
which was the cause of labels being saved to parent folder.

* Implement path normalization for command arguments.

Renamed 'predefined_classes_file' parameter to 'class_file'.

libs/create_ml_io.py

@@ -97,7 +97,7 @@ class CreateMLReader:
         self.json_path = json_path
         self.shapes = []
         self.verified = False
-        self.filename = file_path.split("/")[-1:][0]
+        self.filename = os.path.basename(file_path)
         try:
             self.parse_json()
         except ValueError:

libs/labelFile.py

@@ -39,18 +39,15 @@ class LabelFile(object):
         self.verified = False
 
     def save_create_ml_format(self, filename, shapes, image_path, image_data, class_list, line_color=None, fill_color=None, database_src=None):
-        img_folder_path = os.path.dirname(image_path)
-        img_folder_name = os.path.split(img_folder_path)[-1]
+        img_folder_name = os.path.basename(os.path.dirname(image_path))
         img_file_name = os.path.basename(image_path)
-        output_file_path = "/".join(filename.split("/")[:-1])
-        output_file = output_file_path + "/" + img_folder_name + JSON_EXT
 
         image = QImage()
         image.load(image_path)
         image_shape = [image.height(), image.width(),
                        1 if image.isGrayscale() else 3]
         writer = CreateMLWriter(img_folder_name, img_file_name,
-                                image_shape, shapes, output_file, local_img_path=image_path)
+                                image_shape, shapes, filename, local_img_path=image_path)
         writer.verified = self.verified
         writer.write()