Datasets:

simplexsigil2
/

omnifall

The benchmark uses a sixteen-class activity taxonomy. Staged datasets use classes 0-9. OF-ItW and OF-Syn use the full range 0-15. The extended classes (10-15) are infrequent and can be mapped to "other" (class 9) for compatibility.

Core Classes (0-9, all datasets)

0|walk - Move around, including jogging and running and "drunk walking", but only if it is not part of some special exercise like pulling your knees up. Not when pushing a large object like a chair, but included carrying something small like an apple.
1|fall - The act of falling (from any previous state). Includes falling on a bed, if the process is not a controlled lying down with arms as support.
2|fallen - Being on the ground or a mattress after a fall.
3|sit_down - Sitting down on bed or chair or ground.
4|sitting - Sitting on bed or chair or ground.
5|lie_down - Lying down intentionally (in contrast to a fall) on ground or bed.
6|lying - Being in a lying position (in bed or on the ground) after intentionally getting into that position.
7|stand_up - Standing up from a fallen state, from lying or sitting. Includes getting from lying position into sitting position.
8|standing - Standing around without walking.
9|other - Any other activity, including e.g. walking while pushing an object like a chair.

Extended Classes (10-15, OF-ItW and OF-Syn)

These classes capture additional activities observed in genuine accident and synthetic videos. They do not occur in staged datasets.

10|kneel_down - Transitioning from standing or another posture to a kneeling position.
11|kneeling - Being in a kneeling position (static posture).
12|squat_down - Transitioning to a squatting position.
13|squatting - Being in a squatting position (static posture).
14|crawl - Crawling on hands and knees or similar locomotion on the ground.
15|jump - Jumping action, including vertical jumps and jumps from elevated positions.

Motion Types

There are two types of motions: dynamic ones like walk or stand_up and static ones like fallen, sitting, lying.

Dynamic motions are annotated starting from the first frame that belongs to that action. For example, the transition from walk to fall begins at the first frame where the motion visibly diverges from walking.

Static motions begin at the first frame where the person reaches a resting state. For sit_down, the label ends when the person stops adjusting their body position. For fall, the label ends when inertia-driven movement stops, and the subsequent fallen segment may still contain ground-level movement unrelated to the fall or recovery.

Label Sequences

There are natural sequences of labels like fall, fallen, stand_up. However, these do not always appear together. A person might stand up directly after falling without a fallen segment, or sit down and immediately stand up without a sitting segment.

Lying down is intentional (in contrast to fall). Falls can follow sit_down or lie_down when falling from a chair or bed.

Getting from a lying position to sitting counts as stand_up, even if the person remains seated. A full sequence might be: lying, stand_up, sitting, stand_up (lying in bed, sitting up, pausing, then fully standing).

The distinction between sit_down followed by lie_down versus a single lie_down depends on whether there is a moment of rest in the sitting position. If the person transitions directly from standing through sitting to lying without pause, only lie_down is labeled.

Annotation Process

The annotation video below demonstrates how VGG VIA was used for dense temporal annotation. Pre-existing dataset labels served as visual aid, but all videos were relabeled using OmniFall's label definitions to ensure consistency. The example shows CMDFall, which already provides relatively detailed labels; other source datasets have sparser original annotations.

Blurred regions in the video were added in post-processing to protect subject privacy on this page.