nx_essential3d.nx
buildroot/runtime/nx_essential3d.nx
about
nx_essential3d.nx -- ESSENTIAL MATRIX estimation (8-point algorithm), the piece that recovers relative camera
pose from 2D image correspondences with UNKNOWN poses = the front of two-view SfM (cadtwin P1). Reuses the
SVD-FREE power-iteration null-space tool proven in nx_register3d: the 8-point solves A f = 0 (f = smallest
eigenvector of A^T A), found by power-iterating a Gershgorin-shifted (cI - A^T A). Calibrated cameras ->
ESSENTIAL matrix E s.t. x'^T E x = 0 for corresponding normalized image points x,x'. Benchmarked by the
HELD-OUT epipolar residual (E must satisfy the constraint on points it was NOT fit to = not overfit).
Composes with nx_recon3d (E -> pose -> triangulate). All Q14 fixed-point, deterministic. license_tier: ORIGINAL
dependencies 2 imports · 2 importers
imports: nx_recon3d.nxnx_vecmath.nx
imported by: nx_photogram_front.nxnx_recon2view_gate.nx
structs
| none |
consts
| 10 | const E3_MAGIC_23170: i64 = 23170 |
| 11 | const E3_MAGIC_1024: i64 = 1024 |
| 12 | const E3_MAGIC_2048: i64 = 2048 |
| 14 | const E3_Q: i64 = 16384 |
functions
| 17 | func e3_projn(cx: i64, cy: i64, cz: i64, basis: *i64, x: i64, y: i64, z: i64, out2: *i64) -> i64 |
| 32 | func e3_row(nx: i64, ny: i64, nxp: i64, nyp: i64, out9: *i64) -> i64 called by 1: e3_estimate_norm |
| 46 | func e3_abs(a: i64) -> i64 { if a < 0 { return 0 - a } return a } |
| 47 | func e3_isqrt(n: i64) -> i64 { return vm_isqrt(n) } |
| 50 | func e3_estimate(a: *i64, nrows: i64, out_e9: *i64) -> i64 |
| 126 | func e3_normset(c: *i64, n: i64, cn: *i64, t: *i64) -> i64 |
| 155 | func e3_mat3T(a: *i64, o: *i64) -> i64 called by 1: e3_estimate_norm |
| 161 | func e3_mat3mul(a: *i64, b: *i64, o: *i64) -> i64 called by 1: e3_estimate_norm |
| 174 | func e3_estimate_norm(c0: *i64, c1: *i64, n: i64, out_e: *i64) -> i64 |
| 209 | func e3_residual(e9: *i64, nx: i64, ny: i64, nxp: i64, nyp: i64) -> i64 |