Update README.md

README.md

@@ -42,16 +42,30 @@ Quick links:
 
 ## Loading
 ```python
-pixmo_points_dataset = datasets.load_dataset("allenai/pixmo-points")
+data = datasets.load_dataset("allenai/pixmo-points")
 ```
 
 ## Data Format
-Images are stored as URLs that will need to be downloaded separately. 
+Images are stored as URLs that will need to be downloaded separately. Note image urls can be repeated in the data.
+
+The `points` fields contains the x, y coordinates specified in pixels.
+The `label` field contains the string of name of what is being pointed at, this can be a simple object a more complex referring expression.
+
+
+## Image Checking
 Image hashes are included to support double-checking that the downloaded image matches the annotated image. 
 It can be checked like this:
 
+```python
+from hashlib import sha256
+import requests
+
+example = data[0]
+image_bytes = requests.get(example["image_url"]).content
+byte_hash = sha256(image_bytes).hexdigest()
+assert byte_hash == example["image_sha256"]
 ```
-```
+
 
 ## License
 This dataset is licensed under ODC-BY-1.0. It is intended for research and educational use in accordance with Ai2's [Responsible Use Guidelines](https://allenai.org/responsible-use).