{"artifact_id":"L1-053","layer":"L1","title":"Electronic Portal Imaging (EPID)","domain":"Medical Imaging","sub_domain":"MV X-ray treatment-verification imaging","physics_fingerprint":{"L_DAG":2.8,"title":"Electronic Portal Imaging (EPID)","domain":"Medical Imaging","carrier":"x_ray","primitives":["L.mv_xray_source","L.patient_attenuation","D.amorphous_silicon_panel","int.spatial"],"sub_domain":"MV X-ray treatment-verification imaging","noise_model":"shot_poisson","problem_class":"linear_inverse","solution_space":"2D_attenuation_projection","difficulty_delta":3,"integration_axis":"spatial","sensing_mechanism":"portal_imaging_mv"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 2D attenuation projection is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is well-conditioned (kappa_eff ~= 9); scatter dominates the stability cliff; optical_glare and the remaining mismatch parameters contribute higher-order bias terms. Photon-shot-noise-limited (poisson counting) sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":1024,"W":1024,"MU":5,"scatter":0.2,"pixel_mm":0.4,"MV_energy":6,"optical_glare":0.0,"panel_saturation":0.0},"input_format":"measurement_only","problem_class":"portal_imaging","forward_operator":"portal_imaging_forward","epsilon_fn_center":"25.0"},"omega_bounds":{"H":512,"W":512,"MU":[0.1,200],"scatter":[0.0,0.5],"pixel_mm":[0.1,2.0],"MV_energy":[4,18],"optical_glare":[0.0,0.3],"panel_saturation":[0.0,0.3],"beam_energy_drift":[0.0,0.05]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["portal_imaging"],"allowed_omega_dimensions":["H","W","MV_energy","MU","pixel_mm","scatter","optical_glare","panel_saturation","scatter","optical_glare","panel_saturation","beam_energy_drift"],"allowed_forward_operators":["portal_imaging_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":180,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x676d810a8ca49f3336d11f5cfa073fd2f42f6924056eb2ec95986082c396455d","chain_tx_hash":"0x9e7fd79dbfb70f9a70cfaa77bc34413b1cd089fcb53a01f687ad94ea4ff1ae0f","chain_block":41552302}