The cloth collapse theory is proposed by the head of STURP, John Jackson.
Russ Brealt’s interview with John Jackson on his theory of image formation:
Paper describing the cloth collapse theory:
https://www.shroud.com/pdfs/ssi34part3.pdf
Here’s the sequence of steps:
1. The body was wrapped with the shroud and the side strip was wound around the body.
2. While the body was in rigor mortis and before decomposition, the body dematerialized, similar to teleportation in Star Trek.
3. During dematerialization, the body disappearing would cause a vacuum of where the body used to be. This would cause the cloth to collapse into the vacuum. The top cloth would collapse down and the bottom cloth would collapse up as the cloth moves towards the central plane of the body.
4. During a fraction of a second while the body was dematerializing, the cloth would interact with the dematerializing body and it would form the image on the cloth.
5. The entire shroud would then fall via gravity onto the surface with the side strip still wound around the shroud.
The photographic negative effect is explained by the cloth interacting with the dematerializing body. The dark areas is where the cloth interacted with the disappearing body.
The depth effect is explained by the amount of time the cloth is interacting with the body. The closer the cloth is to the body, the more it would interact with the dematerialization process and produce more colored fibers.
Unlike a true x-ray where it would go through the entire body, the x-ray effect on the shroud is only for a certain depth of the body, The cloth collapse theory explains this since the cloth would only interact with the body for a short distance at it travels through the body before it entirely disappears.
The angle encoding is also explained by more cloth would pass through the body when the angle of the cloth relative to the plane of the body is lower. When the angle is high, like the top of the head and sides of the body, less of the cloth would interact with the body. This also explains the missing ears.
Exactly what causes the oxidation/dehydration of the linen fibers is uncertain. It could be light or some radiation interaction while the body was dematerializing. Most likely the process started at the head, since the head image is the darkest, and then travelled down to the feet. This also accounts for the faint image on the back of the cloth in the head area since the cloth fell through to the other side of the cloth while the body was dematerializing.
Because of the angle of the cloth relative to the body, it can cause second degree image distortions of making things appear longer (fingers, facial features).
Dematerializing also explains the lack of any evidence of breakage or smearing of blood since the body simply disappeared.
Because the bottom side and top side of the cloth moved towards each other, it explains why the ventral and dorsal images are fairly uniform.
Sequence from a Biblical perspective:
1. Jesus was wrapped in the shroud in Joseph’s tomb on Friday.
2. On Sunday, Jesus was resurrected from the dead while he was wrapped in the shroud inside the tomb.
3. When the beloved disciple came to the tomb and looked inside, he saw the linen clothes (the main shroud with the side strip wound around it). The beloved disciple, since he was Lazarus, knew first hand what it was like to be buried in a shroud. What he saw looked like the body simply vanished within the shroud, instead of anyone unwrapping the side strip and opening the shroud. He was then the first to believe that Jesus rose from the dead.
Jhn 20:8 Then went in also that other disciple, which came first to the sepulchre, and he saw, and believed.
https://debatingchristianity.com/forum/viewtopic.php?p=1123740#p1123740