The Mask module allows you to create a black mask that will be applied to the image. This function is useful if you want to cover a certain part of the image, which appears in the same place in all images. If possible, it is better to crop that part using the Preprocess module to reduce the input image.
The mask can also be applied to a heatmap if this option is ticked at the top panel.
This module uses the brush and rubber tools for painting the mask. To change the brush size or switch between the brush and eraser, you can either use the sliders at the top, or you can use shortcuts, which can be found in the Help section under the ‘?’ symbol.
If the images have different aspect ratios, the mask is transformed to always cover the entire image.