Support for PNG files at 1K as a fallback. Error messages.

td01_natural-ground-textures.py

@@ -35,13 +35,13 @@ class NaturalGroundTextures(datasets.GeneratorBasedBuilder):
     VERSION = datasets.Version("0.1.0")
 
     BUILDER_CONFIGS = [
-        datasets.BuilderConfig(name="4K", version=VERSION, description="The original resolution dataset."),
-        datasets.BuilderConfig(name="2K", version=VERSION, description="Half-resolution dataset."),
-        datasets.BuilderConfig(name="1K", version=VERSION, description="Quarter-resolution dataset."),
-        
+        datasets.BuilderConfig(name="JXL@4K", version=VERSION, description="The original resolution dataset."),
+        datasets.BuilderConfig(name="JXL@2K", version=VERSION, description="Half-resolution dataset."),
+        datasets.BuilderConfig(name="JXL@1K", version=VERSION, description="Quarter-resolution dataset."),
+        datasets.BuilderConfig(name="PNG@1K", version=VERSION, description="Fallback version of the dataset."),
     ]
 
-    DEFAULT_CONFIG_NAME = "2k"
+    DEFAULT_CONFIG_NAME = "JXL@2K"
 
     def _info(self):
         return datasets.DatasetInfo(
@@ -58,12 +58,18 @@ class NaturalGroundTextures(datasets.GeneratorBasedBuilder):
         )
 
     def _split_generators(self, dl_manager):
-        data_dir = dl_manager.download_and_extract(INDEX_URLS)
+        data_dir = dl_manager.download(INDEX_URLS)
         train_lines = [json.loads(l) for l in open(data_dir["train"], "r", encoding="utf-8").readlines()]
         test_lines = [json.loads(l) for l in open(data_dir["test"], "r", encoding="utf-8").readlines()]
 
-        train_files = dl_manager.download_and_extract([(DOWNLOAD_PREFIX + '/train/' + row['file_name']) for row in train_lines])
-        test_files = dl_manager.download_and_extract([(DOWNLOAD_PREFIX + '/test/' + row['file_name']) for row in test_lines])
+        def _get_file_url(row, split):
+            file_name = row['file_name']
+            if self.config.name[:3] == "PNG":
+                file_name = file_name.replace('.jxl', '.png')
+            return (DOWNLOAD_PREFIX + '/' + split + '/' + file_name)
+
+        train_files = dl_manager.download([_get_file_url(row, split='train') for row in train_lines])
+        test_files = dl_manager.download([_get_file_url(row, split='test') for row in test_lines])
 
         return [
             datasets.SplitGenerator(datasets.Split.TRAIN, dict(lines=train_lines, filenames=train_files)),
@@ -71,18 +77,28 @@ class NaturalGroundTextures(datasets.GeneratorBasedBuilder):
         ]
 
     def _generate_examples(self, lines, filenames):
-        from jxlpy import JXLImagePlugin
-        import PIL.Image
+        try:
+            if self.config.name[:3] == "JXL":
+                from jxlpy import JXLImagePlugin
+            import PIL.Image
+        except (ImportError, ModuleNotFoundError):
+            logger = datasets.logging.get_logger()
+            logger.critical('\n\n\nERROR: Please install `jxlpy` from PyPI to use JPEG-XL images.\n')
+            raise SystemExit
 
         for key, (data, filename) in enumerate(zip(lines, filenames)):
-            image = PIL.Image.open(filename, formats=["jxl"])
+            # Load the images from disk with the correct format.
+            image = PIL.Image.open(filename, formats=[self.config.name[:3].lower()])
             sz = image.size
 
-            if self.config.name == "1K":
+            # PNG files only available at quarter resolution.
+            if self.config.name[:3] == "PNG":
+                sz = (sz*4, sz*4)
+
+            # Resize the images as specified by the user.
+            if self.config.name[-2:] == "1K":
                 image = image.resize(size=(sz[0]//4, sz[1]//4), resample=PIL.Image.Resampling.LANCZOS)
-            elif self.config.name == "2K":
+            elif self.config.name[-2:] == "2K":
                 image = image.resize(size=(sz[0]//2, sz[1]//2), resample=PIL.Image.Resampling.LANCZOS)
-            else:
-                assert self.config.name == "4K"
 
             yield key, {"image": image, "set": data["set"]}