Update README.md

README.md

@@ -10,4 +10,107 @@ tags:
 - chart
 size_categories:
 - 10K<n<100K
----
+---
+
+# Bar Chart Annotation Dataset
+
+A collection of synthetic bar chart images with detailed structural annotations. Split into three subsets for different stages of a chart understanding pipeline.
+
+---
+
+## Subsets
+
+| Subset | Folder | Train | Test |
+|---|---|---|---|
+| `encoder_training` | `hf_ready/encoder_training/` | 100,000 | 100 |
+| `decoder_training` | `hf_ready/decoder_training/` | 17,000 | 3,400 |
+| `pipeline_testing` | `hf_ready/pipeline_testing/` | — | 100 |
+
+Each subset is a standalone HuggingFace dataset (its own repo), formatted as sharded Parquet files under a `data/` subfolder.
+
+---
+
+## Columns
+
+| Column | Type | Description |
+|---|---|---|
+| `filename` | `string` | Original file stem (e.g. `train_42`) — use to reconstruct or cross-reference source files |
+| `image` | `binary` | Original PNG bytes (RGBA, 1272×954) |
+| `annotation` | `string` | Verbatim JSON annotation — identical to the source `.json` files |
+| `chart_type` | `string` | `"vertical"` or `"horizontal"` |
+| `title` | `string` | Chart title text |
+| `num_features` | `int32` | Number of data features (legend entries) |
+| `num_categories` | `int32` | Number of category-axis ticks |
+| `value_min` | `float32` | Value axis minimum |
+| `value_max` | `float32` | Value axis maximum |
+
+---
+
+## Loading
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("<org>/encoder_training")
+sample = ds["train"][0]
+
+# Image
+from PIL import Image
+from io import BytesIO
+img = Image.open(BytesIO(sample["image"]))
+
+# Annotation (full structure, unchanged)
+import json
+ann = json.loads(sample["annotation"])
+# ann["chart_metadata"] — title, type, bar_width, legend, origin, size
+# ann["data"]           — category_axis, value_axis, features
+```
+
+---
+
+## Annotation Format
+
+Each annotation follows this schema (see `format.json` for the full JSON Schema):
+
+```
+{
+  "chart_metadata": {
+    "title":     { "text": "...", "bbox": [x1, y1, x2, y2] },
+    "type":      "vertical" | "horizontal",
+    "bar_width": <int>,
+    "legend": {
+      "bbox": [...],
+      "entries": [
+        { "feature": { "text": "...", "bbox": [...] },
+          "patch":   { "bbox": [...] } }
+      ]
+    },
+    "origin": { "bbox": [...] },
+    "size":   { "bbox": [...] }
+  },
+  "data": {
+    "category_axis": {
+      "label": { "text": "...", "bbox": [...] },
+      "bbox":  [...],
+      "ticks": [ { "label": { "text": "...", "bbox": [...] }, "bbox": [...] } ]
+    },
+    "value_axis": {
+      "label":     { "text": "...", "bbox": [...] },
+      "min_value": <number>,
+      "max_value": <number>,
+      "bbox":      [...],
+      "ticks":     [ { "label": { "text": "...", "bbox": [...] }, "bbox": [...] } ]
+    },
+    "features": [
+      {
+        "feature": "...",
+        "data": [
+          { "category": "...", "value": <number>, "bbox": [...] }
+        ]
+      }
+    ]
+  }
+}
+```
+
+All bounding boxes are `[x1, y1, x2, y2]` in pixel coordinates.