In the beginning, I want to thank all the participants in our arch index study!
From the comparison between the footprints and pressure images so far, we noticed that pressure image might not be a good substitution for footprints. Pressure image can intuitively visualize regions with variable pressure as a heatmap. However, it is not a perfect way to reveal the details when the region bears low pressure. The pressure image is color-coded from the pressure values from the sensor matrix. But when the force added on the sensor increases linearly, the pressure value does not increase linearly. The pressure value rises much faster than the force. So the details in the super low pressure regions might be zeroed out. To preserve the details in the low pressure regions, we amplified the pressure values in the regions and made it more detectable. According to our data analysis so far, the results of pressure sensing technology are very close to the ones from footprints.