Add documentation

cvat/apps/annotation/README.md

@@ -170,44 +170,58 @@ This is native CVAT annotation format.
 - supported shapes - Rectangles, Polygons, Polylines, Points
 
 ### [Pascal VOC](http://host.robots.ox.ac.uk/pascal/VOC/)
+- [Format specification](http://host.robots.ox.ac.uk/pascal/VOC/voc2012/devkit_doc.pdf)
 
 #### Pascal dumper description
-- downloaded file: a zip archive with following structure:
+- downloaded file: a zip archive of the following structure:
  ```bash
- taskname.zip
- ├── frame_000001.xml
- ├── frame_000002.xml
- ├── frame_000003.xml
- └── ...
+ taskname.zip/
+ ├── Annotations/
+ │   ├── <image_name1>.xml
+ │   ├── <image_name2>.xml
+ │   └── <image_nameN>.xml
+ ├── ImageSets/
+ │   └── Main/
+ │   └── default.txt
+ └── labelmap.txt
  ```
- Each annotation `*.xml` file has a name that corresponds to the name of the image file
- (e.g. `frame_000001.xml` is the annotation for the `frame_000001.jpg` image).
- Detailed structure specification of the `*.xml` file can be found
- [here](http://host.robots.ox.ac.uk/pascal/VOC/voc2012/devkit_doc.pdf).
-- supported shapes - Rectangles
-- additional comments: If you plan to use 'truncated' and 'difficult' attributes please add the corresponding
+
+- supported shapes: Rectangles
+- additional comments: If you plan to use `truncated` and `difficult` attributes please add the corresponding
  items to the CVAT label attributes:
  `~checkbox=difficult:false ~checkbox=truncated:false`
 
 #### Pascal loader description
-- uploaded file: a zip archive with following structure:
- ```bash
- taskname.zip
- ├── frame_000001.xml
- ├── frame_000002.xml
- ├── frame_000003.xml
- └── ...
- ```
- It should be possible to match the CVAT frame(imagename) and image filename from the annotation \*.xml
- file (the tag filename, e.g. `<filename>2008_004457.jpg</filename>`). There are 2 options:
- 1. full match between image name and filename from annotation *.xml
- file (in case of a task was created from images or archive of images).
- 1. match by frame number (if CVAT cannot match by name). File name should be in the following format `frame_%6d.jpg`.
- It will be used when task was created from a video.
+- uploaded file: a zip archive of the structure declared above or the following:
+ ```bash
+ taskname.zip/
+ ├── <image_name1>.xml
+ ├── <image_name2>.xml
+ ├── <image_nameN>.xml
+ └── labelmap.txt # optional
+ ```
 
-- supported shapes: Rectangles
-- limitations: Support of Pascal VOC object detection format
-- additional comments: the CVAT task should be created with the full label set that may be in the annotation files
+ The `labelmap.txt` file contains dataset labels. It **must** be included
+ if dataset labels **differ** from VOC default labels. The file structure:
+ ```bash
+ # label : color_rgb : 'body' parts : actions
+ background:::
+ aeroplane:::
+ bicycle:::
+ bird:::
+ ```
+
+ It must be possible for CVAT to match the frame (image name) and file name from annotation \*.xml
+ file (the tag filename, e.g. `<filename>2008_004457.jpg</filename>`). There are 2 options:
+ 1. full match between image name and filename from annotation \*.xml
+ (in cases when task was created from images or image archive).
+ 1. match by frame number (if CVAT cannot match by name). File name should
+ be in the following format `<number>.jpg`.
+ It should be used when task was created from a video.
+
+- supported shapes: Rectangles
+- limitations: Support of Pascal VOC object detection format
+- additional comments: the CVAT task should be created with the full label set that may be in the annotation files
 
 #### How to create a task from Pascal VOC dataset
 1. Download the Pascal Voc dataset (Can be downloaded from the