On the navigation bar, there is a link to the Not annotated section. That section displays all images that have no annotation. It's working exactly in the same way as any other gallery view. You can click on any image to access an Image view.
When you are on an Image View, the navigation bar on the left displays all the concepts attached to the project. Every toggle turned to green means the corresponding concept is associated with the image.
By playing with the toggles, you can then edit the annotations attached to an image:
You can navigate to the next or previous images by using the left and right arrows of your keyboard, or by clicking on the left and right arrow buttons.
To take advantage of the gallery views, you can also make a selection and apply an annotation to all the images that you have previously selected. Here is how you can do that:
Go to a gallery view
Start a selection by hovering on an image and clicking on the small grey icon on the top left corner of the image
You can add as many images as you want to your selection by simply clicking on those images.
Once images are selected, you can click on Change tags, create or modify the annotation and then click on Apply. This will apply the same annotation to all images in your selection and the page will reload. It is likely that some images disappear from the gallery: this is normal and simply means that you have turned the toggle of the current concept to red.
To annotate an image with bounding boxes, you need to access an Image View. There, you can click on the eye icon, next to ANNOTATIONS, on top of the navigation bar: this will either hide or show the image annotations.
To create a new bounding box, click on Add a box, select the concept for this new box, and draw it on the image. There are 2 drawing modes, you can switch between them by pressing the SHIFT key:
Classic mode: click on the position of the first corner of the box, drag the mouse pointer to a second corner. By releasing the mouse, this will create a box.
Extreme points: click on the 4 extremities of your object (top, bottom, left, right) without it necessarily being the corners. The box will be created to frame your object.
To switch from one annotation mode to another, press the Shift key on your keyboard.
You can remove a box directly from the navigation bar, by clicking on the trash icon.
Keyboard shortcuts are available to make the annotation faster and more convenient. You can get the shortcuts list by clicking on the "?" icon on the bottom right: