Demo bi-transparency - Fluoroscopic image sequence 3 (back)

Description

This image sequence is located between the heart and the lungs tissues, over a static background. The heart corresponds to the dark mass on the right, and the lungs to the bright tissues on the left. They are undergoing the same apparent motion at this location. We also observe a surgical clip, that is part of the background.

The estimated displacements are directed toward the past to respect the notations ot the Transparent Motion Constraint. As a result they are in the opposite direction compared to the usual represented velocity direction.

Estimation result at four interesting time instants

Under the considered radiation angulation, the fast motions of the heart are clearly to be seen. The presented images show that its motion is handled correctly during the dyastole (first and third presented images) and the systole (second and fourth images).

Whole processed sequence

We also present the overall processed sequence. It shows the estimated affine motion fields, along with the corresponding frames.
The results are satisfactory for about 80% of time instants. They are erroneous in particular at the transition between dyastole and systole, since the motion constancy over two successive time instant is violated.