Labeling instructions

When you enter the tool, an image from the database will be randomly selected and shown. You can help by annotating as many objects as you can. Note that previously labeled objects may appear on the image. Please do not label previously labeled objects. Once you have completed the image, you can view a new image by pressing the "show next image" button.

The following steps describe how to label an object:

1. Start by pressing the left mouse button at some point along the boundary of the object.
2. Continue clicking along the boundary of the object to create a polygon.
3. Once you have finished clicking along the boundary of the object, either click on the first point or press the right mouse button to complete the polygon.
4. A window will now appear asking for the object's name and attributes. Enter the object's name and provide any additional information you can and click the "Done" button.

Examples

Good object labels:

building	tree	ship	person

Bad object labels:

The building is not entirely labeled. Make sure to scroll to view the entire object.	The same cloud is labeled twice. Please do not label an object that has already been labeled.	There are three people inside this polygon. Whenever possible, please label individual objects and follow closely their boundary.

Entering object information

Use common English words. Try to avoid application specific terms. For instance, avoid doing things such as replacing right arm by ra. This might be useful in the short term but will make difficult reusing the data for other applications in the future. Also, it is always good practice to have data that is itself explanatory.

Also, avoid numbering the objects. It is preferable not to use object names such as car1. The numbering should be avoided if possible. If you need to keep identity information to relate objects across different images you can use the attributes box.

Object naming: Use common English names for objects. Use a name that you think other people are likely to use to describe the same object. You can use several words to describe an object. Example object names: sky, tree, building, road, sidewalk, person, car, chair.

Attributes: Enter a comma separated list of object attributes. You should use this box to enter information about the object such as the color or any other property that be used to describe the object and its visual appearance.

Occluded: Check the corresponding box to indicate if the object is fully visible or not.

Parts: To indicate that an object is composed of a number of parts, you can drag and drop object names from the right panel (see more details bellow).

Labeling guidelines

The following are some recomendations for how to provide annotations that are as useful as possible.

View the entire image: Make sure that your browser occupies the entire screen and that you scroll to see the entire image. If you label an object on the edge of your browser, make sure to scroll so that the entire object is visible.

Follow the object outline: Click on top of the object boundary so that the polygon accurately delineates the object outline. The ideal outline should be good enough for somebody to recognize the object just by seeing the drawn polygon.

Labeling occluded objects: Sometimes objects will be only partially visible. This is especially true for regions like roads, buildings, etc., which become difficult to label when there are many occlusions. We recommend in these cases to complete the boundary as if they were not occluded.

Advanced features

Delete segments: If you want to delete one segment of the polygon before finishing the polygon, press the delete key. Once the polygon is closed, you can not delete control points or add new segments, but you can modify the location of the control points.

Modify control points: Once you have finished a polygon, you can modify individual control points. If you click on top of the polygon, the control points will appear. You can select one of the control points (hold the left mouse button down) and move it to a new position. Then click anywhere in the image to deselect the polygon. This will also save the modified polygon.

Delete entire polygon: Select the polygon. You will have the option to delete the polygon. You can only edit polygons that you have entered before. You can not delete polygons by other users.

Adding parts: To add parts first you need to trace the polygons that correspond to the full object and each of the parts as if they were individual objects. Once they are labeled you can introduce their part-of relationship. The object list in the right side allows indicating with objects are parts of others. If you drag and drop one object tag on top of another, the list will show the dropped object as being part of the other. You can create arbitrary hierarchies with multiple levels with objects composed of parts and the parts composed of more parts and so on.