Add a heatmap

Heatmap is an optional ArFrame pipeline step. It is executed at each new gaze position to update heatmap image.

Enable and display ArFrame heatmap

ArFrame.heatmap can be enabled with a dedicated JSON entry.

Here is an extract from the JSON ArFrame configuration file where heatmap is enabled and displayed:

{
    "argaze.ArFeatures.ArFrame": {
        "name": "My FullHD screen",
        "size": [1920, 1080],
        ...
        "heatmap": {
            "size": [320, 180],
            "sigma": 0.025,
            "buffer": 0
        },
        ...
        "image_parameters": {
            ...
            "heatmap_weight": 1
        }
    }
}

Now, let's understand the meaning of each JSON entry.

size

The heatmap image size in pixel. Higher size implies higher CPU load.

sigma

The gaussian point spreading to draw at each gaze position.

buffer

The size of point spread images buffer (0 means no buffering) to visualize only last N gaze positions.

heatmap_weight

The weight of heatmap overlay in ArFrame.image between 0 and 1.