Update README.md

add annotation format

README.md

@@ -4,7 +4,64 @@ license_name: server-side-public-license
 license_link: https://www.mongodb.com/licensing/server-side-public-license
 ---
 
-## Datasets
+# FashionFail Dataset
+
+## Annotation format
+
+We follow the annotation format of the [COCO dataset](https://cocodataset.org/#format-data). The annotations are stored in the [JSON format](http://www.json.org/) and are organized as follows:
+
+```
+{
+ "info"           : info,
+ "licenses"       : [license],
+ "categories"     : [category],
+ "images"         : [image],
+ "annotations"    : [annotation],
+}
+
+info{
+  "year"          : int,
+  "version"       : str,
+  "description"   : str,
+  "contributor"   : str,
+  "url"           : str,
+  "date_created"  : datetime,
+}
+
+license{
+  "id"            : int,
+  "name"          : str,
+  "url"           : str,
+}
+
+category{
+  "id"            : int,
+  "name"          : str,
+  "supercategory" : str,
+}
+
+image{
+  "id"            : int,
+  "file_name"     : str,
+  "height"        : int,
+  "width"         : int,
+  "license"       : int,
+  "original_url"  : str,
+}
+
+annotation{
+  "id"            : int,
+  "image_id"      : int,
+  "category_id"   : int,
+  "area"          : int,
+  "iscrowd"       : int,  # always 0 as instances represent a single object
+  "bbox"          : [x,y,width,height],
+  "segmentation"  : RLE,  # RLE: {"size", (height, widht), "counts": str}
+}
+```
+
+
+### Comparison with Fashionpedia
 
 Fashionpedia(FP) has the following splits (with number of images); *Train* (45,623), *Validation* (1,158), and *Test* (2,044). \
 FashionFail(FF) has the following splits (with number of images); *Train* (1,344), *Validation* (150), and *Test* (1,001).