Source-cited technical reference
AI face swap glossary
Plain-English definitions for 24 terms used in face-swap research and evaluation, each paired with a primary source and a boundary that prevents overclaiming.
Direct answer
Face-swap terminology needs a definition and a limit
A source face supplies identity cues. Target media supplies the scene and intended non-identity attributes. Detection, alignment, masking, and generation describe parts of a workflow; identity similarity, perceptual metrics, and human review answer different evaluation questions.
Term index
Jump to the concept you need
Workflow foundations
Workflow foundations
The media roles and geometric preprocessing terms that define what enters a face-swap workflow.
Face swap
#Also called: AI face swap, face swapping
A computer-vision task that transfers identity cues from a source face into a target image or video while attempting to preserve target attributes such as pose, expression, hair, and background.
Evidence boundary: This is a task definition, not a guarantee that every system preserves every attribute or that a particular use has permission.
Primary sources: PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion; Fine-Grained Face Swapping via Regional GAN Inversion
Source face
#Also called: source identity, identity reference
The person or reference image that supplies the identity cues intended for the generated face.
Evidence boundary: The source does not normally define the target scene, body, hair, pose, or background, and the exact split depends on the method.
Primary sources: PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion; Reinforced Disentanglement for Face Swapping without Skip Connection
Target media
#Also called: target image, target video
The image or video that supplies the scene and the non-identity attributes a face-swap method attempts to retain.
Evidence boundary: Methods differ in which target attributes they retain, so target preservation must be evaluated rather than assumed.
Primary sources: PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion; DynamicFace: High-Quality and Consistent Face Swapping for Image and Video
Face detection
#Also called: face localisation, face localization
The process of locating one or more face regions in an image or video frame before alignment, feature extraction, or generation.
Evidence boundary: A detected face region is not an identity decision, a consent check, or proof that later processing will succeed.
Primary sources: RetinaFace: Single-Shot Multi-Level Face Localisation in the Wild
Facial landmarks
#Also called: face landmarks, landmark points
Estimated facial key points, such as eye corners, nose, and mouth locations, used to describe facial geometry for alignment or conditioning.
Evidence boundary: Landmark layouts, point counts, and error units vary by detector and protocol; they are not directly interchangeable.
Primary sources: RetinaFace: Single-Shot Multi-Level Face Localisation in the Wild; DiffSwap: High-Fidelity and Controllable Face Swapping via 3D-Aware Masked Diffusion
Face alignment
#Also called: facial alignment, aligned face crop
A geometric normalization step that uses detected facial structure to place a face into a consistent crop, scale, and orientation for later processing.
Evidence boundary: Alignment conventions and transforms vary, and an aligned crop does not establish identity, quality, or permission.
Primary sources: RetinaFace: Single-Shot Multi-Level Face Localisation in the Wild; ArcFace: Additive Angular Margin Loss for Deep Face Recognition
Identity and preservation
Identity and preservation
The concepts used to separate source identity cues from the target attributes a result attempts to retain.
Face embedding
#Also called: identity embedding, facial feature vector
A learned numerical representation designed so that facial images can be compared in a feature space under a specific recognition model and preprocessing protocol.
Evidence boundary: Vector dimensions, distance functions, and decision thresholds depend on the model and evaluation setup; an embedding is not inherently an identity verdict or mathematically guaranteed to be non-reconstructable.
Primary sources: ArcFace: Additive Angular Margin Loss for Deep Face Recognition
Identity similarity
#Also called: identity retention, identity preservation score
A protocol-dependent comparison between source-identity and output representations, commonly computed from a named face encoder and similarity function.
Evidence boundary: Scores are not portable across encoders, crops, datasets, thresholds, or demographics and should not be presented as a biometric verdict for one output.
Primary sources: ArcFace: Additive Angular Margin Loss for Deep Face Recognition; PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion
Target-attribute preservation
#Also called: attribute preservation, target consistency
The extent to which a result retains intended target characteristics such as pose, expression, hair, lighting, clothing, and background while changing facial identity cues.
Evidence boundary: The evaluated attributes and estimators must be named; one aggregate score can conceal failures in an individual attribute.
Primary sources: PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion; DynamicFace: High-Quality and Consistent Face Swapping for Image and Video
Face mask
#Also called: swap mask, facial mask
A spatial map that identifies which image region can be generated, blended, or evaluated as part of a face-swap operation.
Evidence boundary: Mask construction and semantics vary by method; a mask does not by itself solve occlusion, boundary, or color inconsistency.
Primary sources: DiffSwap: High-Fidelity and Controllable Face Swapping via 3D-Aware Masked Diffusion; Fine-Grained Face Swapping via Regional GAN Inversion
Face parsing
#Also called: facial semantic segmentation
Pixel-level semantic segmentation of facial components and surrounding regions, such as skin, eyes, mouth, hair, or background.
Evidence boundary: Label sets and segmentation quality depend on the parser and dataset, and incorrect regions can propagate into later synthesis or compositing.
Primary sources: Fine-Grained Face Swapping via Regional GAN Inversion
Face-boundary blending
#Also called: boundary blending, face compositing
The compositing step that transitions a synthesized facial region into the target around skin tone, edges, lighting, and nearby content.
Evidence boundary: A visually smooth boundary does not establish correct identity, natural internal features, or consistent behavior across video frames.
Primary sources: Fine-Grained Face Swapping via Regional GAN Inversion; Reinforced Disentanglement for Face Swapping without Skip Connection
Occlusion
#Also called: face obstruction, occluded face
A condition in which part of a face is hidden by hair, hands, glasses, objects, another person, or the image boundary.
Evidence boundary: Occlusion handling is method- and scene-dependent; a benchmark must specify the affected region and viewing conditions.
Primary sources: Fine-Grained Face Swapping via Regional GAN Inversion; DynamicFace: High-Quality and Consistent Face Swapping for Image and Video
Head pose
#Also called: face pose, head orientation
The estimated orientation of a head relative to the camera, often represented by yaw, pitch, and roll or by landmarks and 3D parameters.
Evidence boundary: Pose values depend on the estimator and coordinate convention; matching pose alone cannot predict output realism.
Primary sources: DiffSwap: High-Fidelity and Controllable Face Swapping via 3D-Aware Masked Diffusion; PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion
Facial expression
#Also called: expression preservation
The visible configuration of facial features associated with movements such as smiling, blinking, or opening the mouth, often treated as a target attribute in face swapping.
Evidence boundary: Expression labels and parameters are estimator-dependent and can miss subtle, asymmetric, or culturally interpreted behavior.
Primary sources: PixSwap: High-Resolution Face Swapping for Effective Reflection of Identity via Diffusion; DynamicFace: High-Quality and Consistent Face Swapping for Image and Video
Video consistency
Video consistency
Motion and frame-sequence concepts that do not exist in a single still image.
Temporal consistency
#Also called: temporal coherence, frame-to-frame consistency
The stability of identity cues, target attributes, and visual detail across consecutive video frames rather than in one isolated frame.
Evidence boundary: A high consistency measure can preserve the wrong result consistently, so identity correctness and visible quality must be evaluated separately.
Primary sources: DynamicFace: High-Quality and Consistent Face Swapping for Image and Video; CanonSwap: High-Fidelity and Consistent Video Face Swapping via Canonical Space Modulation
Optical flow
#Also called: motion field, pixel correspondence
An estimated dense motion field that maps image locations between frames and can support motion analysis, warping, or temporal diagnostics.
Evidence boundary: Optical flow is an estimate that can fail around occlusion, blur, lighting changes, and newly visible regions; it is not a quality score by itself.
Primary sources: RAFT: Recurrent All-Pairs Field Transforms for Optical Flow; CanonSwap: High-Fidelity and Consistent Video Face Swapping via Canonical Space Modulation
Evaluation
Evaluation
Metrics and review protocols that answer different quality questions under explicit conditions.
Structural Similarity Index (SSIM)
#Also called: SSIM
A full-reference image similarity measure that compares luminance, contrast, and structure between a test image and a reference image.
Evidence boundary: SSIM requires a meaningful aligned reference, is not face-specific, and its value depends on scale, windowing, color handling, and preprocessing.
Primary sources: Image Quality Assessment: From Error Visibility to Structural Similarity
Learned Perceptual Image Patch Similarity (LPIPS)
#Also called: LPIPS, learned perceptual similarity
A perceptual distance based on deep network features that was evaluated against human judgments of image-patch similarity.
Evidence boundary: LPIPS is not an identity score; values depend on the selected network, calibration, image preparation, and comparison protocol.
Primary sources: The Unreasonable Effectiveness of Deep Features as a Perceptual Metric
Frechet Inception Distance (FID)
#Also called: FID
A set-level distance between feature distributions from generated and reference image collections, originally computed with Inception features.
Evidence boundary: FID is not a defensible single-image score, and results depend on sample count, feature extractor, preprocessing, reference set, and implementation.
Primary sources: GANs Trained by a Two Time-Scale Update Rule Converge to a Local Nash Equilibrium; Rethinking FID: Towards a Better Evaluation Metric for Image Generation
No-reference quality assessment
#Also called: NR-IQA, blind image quality assessment
A method that estimates visual quality from an output without requiring a paired pristine reference image.
Evidence boundary: Its validity depends on training data and validation design; a score can fail on unseen methods, content, or distortions.
Primary sources: Rank-based No-reference Quality Assessment for Face Swapping
Human-review scorecard
#Also called: human evaluation rubric, output review rubric
A repeatable rubric that asks a reviewer to record visible criteria, rating anchors, critical gates, and notes for a specific output.
Evidence boundary: It records structured human observations, not model accuracy, biometric identity, a probability, or a provider-wide ranking.
Primary sources: DeepSwapAI face swap output quality scorecard; Rank-based No-reference Quality Assessment for Face Swapping
Provenance
Provenance
Standards for recording where digital content came from and what happened to it.
C2PA
#Also called: Coalition for Content Provenance and Authenticity
An open technical standard for recording tamper-evident provenance information about digital content through signed manifests, assertions, ingredients, and claims.
Evidence boundary: C2PA can provide provenance evidence and tamper signals, but the specification does not determine whether depicted content is true, accurate, or ethically permitted.
Primary sources: C2PA Technical Specification 2.4; C2PA Explainer 2.3
Content Credentials
#Also called: C2PA Content Credentials, content provenance credentials
The user-facing presentation of provenance information associated with a digital asset through the C2PA ecosystem.
Evidence boundary: Availability and displayed details depend on the credential, signer, validator, asset, and platform; a credential is not a declaration that content is factually true.
Primary sources: C2PA Explainer 2.3; C2PA Technical Specification 2.4
Metric interpretation
Four rules prevent misleading comparisons
Name the relationship
Identity metrics normally compare the output with the source identity. Pose and expression preservation normally compare the output with the target. These are different questions.
Hold the protocol constant
Dataset, crop, evaluator, preprocessing, implementation, sample count, and aggregation can all change a reported value. A shared metric name is not enough.
Keep set-level and single-output evidence separate
FID describes image-set distributions. SSIM and LPIPS require a meaningful comparison reference. A human scorecard records visible observations about one reviewed output.
Do not collapse every quality dimension
Identity, target-attribute preservation, boundaries, occlusion, technical integrity, and temporal stability can fail independently and should remain inspectable.
Glossary questions
How to use these definitions
Does this page reveal the exact DeepSwapAI model stack?
No. It defines industry and research concepts without claiming that every cited method is part of the production implementation.
Can I compare the same metric across two papers?
Only after checking that the datasets, evaluators, preprocessing, implementations, and aggregation rules match.
Can FID measure one output?
No. FID is a distribution-level measure and needs generated and reference image sets.
Do Content Credentials prove an image is true?
No. They provide provenance information and validation signals, not a factual truth judgment.
Apply the terms to one visible output
Use the free scorecard to review identity, boundaries, pose, lighting, occlusion, technical integrity, and video stability without turning one sample into a provider-wide claim.