diff --git a/internal/crop/area.go b/internal/crop/area.go
index 7d314bb94..c2b216333 100644
--- a/internal/crop/area.go
+++ b/internal/crop/area.go
@@ -3,6 +3,7 @@ package crop
 import (
 	"fmt"
 	"image"
+	"math"
 	"strconv"
 	"strings"
 
@@ -60,6 +61,66 @@ func (a Area) FileWidth(size Size) int {
 	return int(float32(size.Width) / a.W)
 }
 
+// Top returns the top Y coordinate as float64.
+func (a Area) Top() float64 {
+	return float64(a.Y)
+}
+
+// Left returns the left X coordinate as float64.
+func (a Area) Left() float64 {
+	return float64(a.X)
+}
+
+// Right returns the right X coordinate as float64.
+func (a Area) Right() float64 {
+	return float64(a.X + a.W)
+}
+
+// Bottom returns the bottom Y coordinate as float64.
+func (a Area) Bottom() float64 {
+	return float64(a.Y + a.H)
+}
+
+// Surface returns the surface area.
+func (a Area) Surface() float64 {
+	return float64(a.W * a.H)
+}
+
+// SurfaceRatio returns the surface ratio.
+func (a Area) SurfaceRatio(area float64) float64 {
+	if area <= 0 {
+		return 0
+	}
+
+	if s := a.Surface(); s <= 0 {
+		return 0
+	} else if area > s {
+		return s / area
+	} else {
+		return area / s
+	}
+}
+
+// Overlap calculates the overlap of two areas.
+func (a Area) Overlap(other Area) (x, y float64) {
+	x = math.Max(0, math.Min(a.Right(), other.Right())-math.Max(a.Left(), other.Left()))
+	y = math.Max(0, math.Min(a.Bottom(), other.Bottom())-math.Max(a.Top(), other.Top()))
+
+	return x, y
+}
+
+// OverlapArea calculates the overlap area of two areas.
+func (a Area) OverlapArea(other Area) (area float64) {
+	x, y := a.Overlap(other)
+
+	return x * y
+}
+
+// OverlapPercent calculates the overlap ratio of two areas in percent.
+func (a Area) OverlapPercent(other Area) int {
+	return int(math.Round(other.SurfaceRatio(a.OverlapArea(other)) * 100))
+}
+
 // clipVal ensures the relative size is within a valid range.
 func clipVal(f float32) float32 {
 	if f > 1 {
diff --git a/internal/crop/area_test.go b/internal/crop/area_test.go
index 3d0618b38..bbebd2615 100644
--- a/internal/crop/area_test.go
+++ b/internal/crop/area_test.go
@@ -137,3 +137,45 @@ func TestParseThumb(t *testing.T) {
 		assert.True(t, AreaFromString(a).Empty())
 	})
 }
+
+func TestArea_SurfaceRatio(t *testing.T) {
+	var a1 = Area{Name: "face", X: 0.308333, Y: 0.206944, W: 0.355556, H: 0.355556}
+	var a2 = Area{Name: "face", X: 0.208313, Y: 0.156914, W: 0.655556, H: 0.655556}
+	var a3 = Area{Name: "face", X: 0.998133, Y: 0.816944, W: 0.0001, H: 0.0001}
+	var a4 = Area{Name: "face", X: 0.298133, Y: 0.216944, W: 0.255556, H: 0.155556}
+
+	assert.Equal(t, 99, int(a1.SurfaceRatio(a1.OverlapArea(a1))*100))
+	assert.Equal(t, 99, int(a1.SurfaceRatio(a1.OverlapArea(a2))*100))
+	assert.Equal(t, 29, int(a2.SurfaceRatio(a2.OverlapArea(a1))*100))
+	assert.Equal(t, 0, int(a1.SurfaceRatio(a1.OverlapArea(a3))*100))
+	assert.Equal(t, 30, int(a1.SurfaceRatio(a1.OverlapArea(a4))*100))
+	assert.Equal(t, 0, int(a1.SurfaceRatio(a3.OverlapArea(a1))*100))
+	assert.Equal(t, 30, int(a1.SurfaceRatio(a4.OverlapArea(a1))*100))
+}
+
+func TestArea_OverlapArea(t *testing.T) {
+	var a1 = Area{Name: "face", X: 0.308333, Y: 0.206944, W: 0.355556, H: 0.355556}
+	var a2 = Area{Name: "face", X: 0.208313, Y: 0.156914, W: 0.655556, H: 0.655556}
+	var a3 = Area{Name: "face", X: 0.998133, Y: 0.816944, W: 0.0001, H: 0.0001}
+	var a4 = Area{Name: "face", X: 0.298133, Y: 0.216944, W: 0.255556, H: 0.155556}
+
+	assert.Equal(t, 0.1264200823986168, a1.OverlapArea(a1))
+	assert.Equal(t, int(a1.Surface()*10000), int(a1.OverlapArea(a1)*10000))
+	assert.Equal(t, 0.1264200823986168, a1.OverlapArea(a2))
+	assert.Equal(t, 0.1264200823986168, a2.OverlapArea(a1))
+	assert.Equal(t, 0.0, a1.OverlapArea(a3))
+	assert.Equal(t, 0.038166598943088825, a1.OverlapArea(a4))
+}
+
+func TestArea_OverlapPercent(t *testing.T) {
+	var a1 = Area{Name: "face", X: 0.308333, Y: 0.206944, W: 0.355556, H: 0.355556}
+	var a2 = Area{Name: "face", X: 0.208313, Y: 0.156914, W: 0.655556, H: 0.655556}
+	var a3 = Area{Name: "face", X: 0.998133, Y: 0.816944, W: 0.0001, H: 0.0001}
+	var a4 = Area{Name: "face", X: 0.298133, Y: 0.216944, W: 0.255556, H: 0.155556}
+
+	assert.Equal(t, 100, a1.OverlapPercent(a1))
+	assert.Equal(t, 29, a1.OverlapPercent(a2))
+	assert.Equal(t, 100, a2.OverlapPercent(a1))
+	assert.Equal(t, 0, a1.OverlapPercent(a3))
+	assert.Equal(t, 96, a1.OverlapPercent(a4))
+}
diff --git a/internal/entity/marker.go b/internal/entity/marker.go
index 758a4d781..0481d7922 100644
--- a/internal/entity/marker.go
+++ b/internal/entity/marker.go
@@ -482,6 +482,11 @@ func (m *Marker) Matched() error {
 	return UnscopedDb().Model(m).UpdateColumns(Values{"MatchedAt": m.MatchedAt}).Error
 }
 
+// Top returns the top Y coordinate as float64.
+func (m *Marker) Top() float64 {
+	return float64(m.Y)
+}
+
 // Left returns the left X coordinate as float64.
 func (m *Marker) Left() float64 {
 	return float64(m.X)
@@ -492,16 +497,31 @@ func (m *Marker) Right() float64 {
 	return float64(m.X + m.W)
 }
 
-// Top returns the top Y coordinate as float64.
-func (m *Marker) Top() float64 {
-	return float64(m.Y)
-}
-
 // Bottom returns the bottom Y coordinate as float64.
 func (m *Marker) Bottom() float64 {
 	return float64(m.Y + m.H)
 }
 
+// Surface returns the surface area.
+func (m *Marker) Surface() float64 {
+	return float64(m.W * m.H)
+}
+
+// SurfaceRatio returns the surface ratio.
+func (m *Marker) SurfaceRatio(area float64) float64 {
+	if area <= 0 {
+		return 0
+	}
+
+	if s := m.Surface(); s <= 0 {
+		return 0
+	} else if area > s {
+		return s / area
+	} else {
+		return area / s
+	}
+}
+
 // Overlap calculates the overlap of two markers.
 func (m *Marker) Overlap(marker Marker) (x, y float64) {
 	x = math.Max(0, math.Min(m.Right(), marker.Right())-math.Max(m.Left(), marker.Left()))
@@ -517,6 +537,11 @@ func (m *Marker) OverlapArea(marker Marker) (area float64) {
 	return x * y
 }
 
+// OverlapPercent calculates the overlap ratio of two markers in percent.
+func (m *Marker) OverlapPercent(marker Marker) int {
+	return int(math.Round(marker.SurfaceRatio(m.OverlapArea(marker)) * 100))
+}
+
 // FindMarker returns an existing row if exists.
 func FindMarker(markerUid string) *Marker {
 	if markerUid == "" {
@@ -552,7 +577,7 @@ func FindFaceMarker(faceId string) *Marker {
 
 // UpdateOrCreateMarker updates a marker in the database or creates a new one if needed.
 func UpdateOrCreateMarker(m *Marker) (*Marker, error) {
-	const d = 0.07
+	const d = 0.0001
 
 	result := Marker{}
 
diff --git a/internal/entity/marker_test.go b/internal/entity/marker_test.go
index aab2cadef..29decfafe 100644
--- a/internal/entity/marker_test.go
+++ b/internal/entity/marker_test.go
@@ -532,3 +532,45 @@ func TestMarker_RefreshPhotos(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestMarker_SurfaceRatio(t *testing.T) {
+	m1 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea1, "lt9k3pw1wowuy1c1", SrcImage, MarkerFace, 100, 65)
+	m2 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea2, "lt9k3pw1wowuy1c2", SrcImage, MarkerFace, 100, 65)
+	m3 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea3, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+	m4 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea4, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+
+	assert.Equal(t, 99, int(m1.SurfaceRatio(m1.OverlapArea(m1))*100))
+	assert.Equal(t, 99, int(m1.SurfaceRatio(m1.OverlapArea(m2))*100))
+	assert.Equal(t, 29, int(m2.SurfaceRatio(m2.OverlapArea(m1))*100))
+	assert.Equal(t, 0, int(m1.SurfaceRatio(m1.OverlapArea(m3))*100))
+	assert.Equal(t, 30, int(m1.SurfaceRatio(m1.OverlapArea(m4))*100))
+	assert.Equal(t, 0, int(m1.SurfaceRatio(m3.OverlapArea(m1))*100))
+	assert.Equal(t, 30, int(m1.SurfaceRatio(m4.OverlapArea(m1))*100))
+}
+
+func TestMarker_OverlapArea(t *testing.T) {
+	m1 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea1, "lt9k3pw1wowuy1c1", SrcImage, MarkerFace, 100, 65)
+	m2 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea2, "lt9k3pw1wowuy1c2", SrcImage, MarkerFace, 100, 65)
+	m3 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea3, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+	m4 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea4, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+
+	assert.Equal(t, 0.1264200823986168, m1.OverlapArea(m1))
+	assert.Equal(t, int(m1.Surface()*10000), int(m1.OverlapArea(m1)*10000))
+	assert.Equal(t, 0.1264200823986168, m1.OverlapArea(m2))
+	assert.Equal(t, 0.1264200823986168, m2.OverlapArea(m1))
+	assert.Equal(t, 0.0, m1.OverlapArea(m3))
+	assert.Equal(t, 0.038166598943088825, m1.OverlapArea(m4))
+}
+
+func TestMarker_OverlapPercent(t *testing.T) {
+	m1 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea1, "lt9k3pw1wowuy1c1", SrcImage, MarkerFace, 100, 65)
+	m2 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea2, "lt9k3pw1wowuy1c2", SrcImage, MarkerFace, 100, 65)
+	m3 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea3, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+	m4 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea4, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
+
+	assert.Equal(t, 100, m1.OverlapPercent(m1))
+	assert.Equal(t, 29, m1.OverlapPercent(m2))
+	assert.Equal(t, 100, m2.OverlapPercent(m1))
+	assert.Equal(t, 0, m1.OverlapPercent(m3))
+	assert.Equal(t, 96, m1.OverlapPercent(m4))
+}
diff --git a/internal/entity/markers.go b/internal/entity/markers.go
index 7360ecf5f..3712d7542 100644
--- a/internal/entity/markers.go
+++ b/internal/entity/markers.go
@@ -1,6 +1,7 @@
 package entity
 
 import (
+	"github.com/photoprism/photoprism/internal/face"
 	"github.com/photoprism/photoprism/pkg/txt"
 )
 
@@ -24,7 +25,7 @@ func (m Markers) Save(fileUID string) error {
 // Contains returns true if a marker at the same position already exists.
 func (m Markers) Contains(other Marker) bool {
 	for _, marker := range m {
-		if marker.OverlapArea(other) > 0.02 {
+		if marker.OverlapPercent(other) > face.OverlapThreshold {
 			return true
 		}
 	}
diff --git a/internal/entity/markers_test.go b/internal/entity/markers_test.go
index 52753acd7..849e76b74 100644
--- a/internal/entity/markers_test.go
+++ b/internal/entity/markers_test.go
@@ -9,7 +9,7 @@ import (
 )
 
 var cropArea1 = crop.Area{Name: "face", X: 0.308333, Y: 0.206944, W: 0.355556, H: 0.355556}
-var cropArea2 = crop.Area{Name: "face", X: 0.308313, Y: 0.206914, W: 0.655556, H: 0.655556}
+var cropArea2 = crop.Area{Name: "face", X: 0.208313, Y: 0.156914, W: 0.655556, H: 0.655556}
 var cropArea3 = crop.Area{Name: "face", X: 0.998133, Y: 0.816944, W: 0.0001, H: 0.0001}
 var cropArea4 = crop.Area{Name: "face", X: 0.298133, Y: 0.216944, W: 0.255556, H: 0.155556}
 
@@ -19,9 +19,12 @@ func TestMarkers_Contains(t *testing.T) {
 		m2 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea2, "lt9k3pw1wowuy1c2", SrcImage, MarkerFace, 100, 65)
 		m3 := *NewMarker(FileFixtures.Get("exampleFileName.jpg"), cropArea3, "lt9k3pw1wowuy1c3", SrcImage, MarkerFace, 100, 65)
 
-		m := Markers{m1}
+		assert.Equal(t, 29, m1.OverlapPercent(m2))
+		assert.Equal(t, 100, m2.OverlapPercent(m1))
 
-		assert.True(t, m.Contains(m2))
+		m := Markers{m2}
+
+		assert.True(t, m.Contains(m1))
 		assert.False(t, m.Contains(m3))
 	})
 	t.Run("Conflicting", func(t *testing.T) {
diff --git a/internal/face/area.go b/internal/face/area.go
index 34cab03b1..a6158479a 100644
--- a/internal/face/area.go
+++ b/internal/face/area.go
@@ -60,7 +60,7 @@ func (a Area) Relative(r Area, rows, cols float32) crop.Area {
 	)
 }
 
-// TopLeft returns the top left position of the face.
+// TopLeft returns the top left position of the area.
 func (a Area) TopLeft() (int, int) {
 	return a.Row - (a.Scale / 2), a.Col - (a.Scale / 2)
 }
diff --git a/internal/face/area_test.go b/internal/face/area_test.go
new file mode 100644
index 000000000..ecf41b455
--- /dev/null
+++ b/internal/face/area_test.go
@@ -0,0 +1,35 @@
+package face
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var area1 = NewArea("face1", 400, 250, 200)
+var area2 = NewArea("face2", 100, 100, 50)
+var area3 = NewArea("face3", 900, 500, 25)
+var area4 = NewArea("face4", 110, 110, 60)
+
+func TestArea_TopLeft(t *testing.T) {
+	t.Run("area1", func(t *testing.T) {
+		x, y := area1.TopLeft()
+		assert.Equal(t, 300, x)
+		assert.Equal(t, 150, y)
+	})
+	t.Run("area2", func(t *testing.T) {
+		x, y := area2.TopLeft()
+		assert.Equal(t, 75, x)
+		assert.Equal(t, 75, y)
+	})
+	t.Run("area3", func(t *testing.T) {
+		x, y := area3.TopLeft()
+		assert.Equal(t, 888, x)
+		assert.Equal(t, 488, y)
+	})
+	t.Run("area4", func(t *testing.T) {
+		x, y := area4.TopLeft()
+		assert.Equal(t, 80, x)
+		assert.Equal(t, 80, y)
+	})
+}
diff --git a/internal/face/detector.go b/internal/face/detector.go
index 0017502f9..c109f2fb8 100644
--- a/internal/face/detector.go
+++ b/internal/face/detector.go
@@ -87,7 +87,7 @@ func Detect(fileName string, findLandmarks bool, minSize int) (faces Faces, err
 		shiftFactor:    0.1,
 		scaleFactor:    1.1,
 		iouThreshold:   0.2,
-		scoreThreshold: 9.0,
+		scoreThreshold: ScoreThreshold,
 		perturb:        63,
 	}
 
@@ -154,10 +154,6 @@ func (d *Detector) Detect(fileName string) (faces []pigo.Detection, params pigo.
 		Dim:    cols,
 	}
 
-	if rows > 800 || cols > 800 {
-		d.scoreThreshold += 9.0
-	}
-
 	params = pigo.CascadeParams{
 		MinSize:     d.minSize,
 		MaxSize:     maxSize,
@@ -180,28 +176,34 @@ func (d *Detector) Detect(fileName string) (faces []pigo.Detection, params pigo.
 
 // Faces adds landmark coordinates to detected faces and returns the results.
 func (d *Detector) Faces(det []pigo.Detection, params pigo.CascadeParams, findLandmarks bool) (results Faces, err error) {
-	var maxQ float32
-
-	// Sort by quality.
+	// Sort by size.
 	sort.Slice(det, func(i, j int) bool {
-		return det[i].Q > det[j].Q
+		return det[i].Scale > det[j].Scale
 	})
 
 	for _, face := range det {
+		// Small faces require higher quality.
+		threshold := d.scoreThreshold
+
+		if face.Scale < 30 {
+			threshold += 11.5
+		} else if face.Scale < 50 {
+			threshold += 9.0
+		} else if face.Scale < 80 {
+			threshold += 6.5
+		} else if face.Scale < 110 {
+			threshold += 2.5
+		}
+
+		// Skip face if quality is too low.
+		if face.Q < threshold {
+			continue
+		}
+
 		var eyesCoords []Area
 		var landmarkCoords []Area
 		var puploc *pigo.Puploc
 
-		if face.Q < d.scoreThreshold {
-			continue
-		}
-
-		if maxQ < face.Q {
-			maxQ = face.Q
-		} else if maxQ >= 20 && face.Q < 15 {
-			continue
-		}
-
 		faceCoord := NewArea(
 			"face",
 			face.Row,
@@ -312,14 +314,20 @@ func (d *Detector) Faces(det []pigo.Detection, params pigo.CascadeParams, findLa
 			}
 		}
 
-		results = append(results, Face{
+		f := Face{
 			Rows:      params.ImageParams.Rows,
 			Cols:      params.ImageParams.Cols,
 			Score:     int(face.Q),
 			Area:      faceCoord,
 			Eyes:      eyesCoords,
 			Landmarks: landmarkCoords,
-		})
+		}
+
+		if results.Contains(f) {
+			// Ignore.
+		} else {
+			results.Append(f)
+		}
 	}
 
 	return results, nil
diff --git a/internal/face/detector_test.go b/internal/face/detector_test.go
new file mode 100644
index 000000000..3bee4a4a4
--- /dev/null
+++ b/internal/face/detector_test.go
@@ -0,0 +1,131 @@
+package face
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/photoprism/photoprism/pkg/fastwalk"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDetect(t *testing.T) {
+	expected := map[string]int{
+		"1.jpg":  1,
+		"2.jpg":  1,
+		"3.jpg":  1,
+		"4.jpg":  1,
+		"5.jpg":  1,
+		"6.jpg":  1,
+		"7.jpg":  0,
+		"8.jpg":  0,
+		"9.jpg":  0,
+		"10.jpg": 0,
+		"11.jpg": 0,
+		"12.jpg": 1,
+		"13.jpg": 0,
+		"14.jpg": 0,
+		"15.jpg": 0,
+		"16.jpg": 1,
+		"17.jpg": 1,
+		"18.jpg": 2,
+		"19.jpg": 0,
+	}
+
+	if err := fastwalk.Walk("testdata", func(fileName string, info os.FileMode) error {
+		if info.IsDir() || filepath.Base(filepath.Dir(fileName)) != "testdata" {
+			return nil
+		}
+
+		t.Run(fileName, func(t *testing.T) {
+			baseName := filepath.Base(fileName)
+
+			faces, err := Detect(fileName, true, 20)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			t.Logf("found %d faces in '%s'", len(faces), baseName)
+
+			if len(faces) > 0 {
+				// t.Logf("results: %#v", faces)
+
+				for i, f := range faces {
+					t.Logf("marker[%d]: %#v %#v", i, f.CropArea(), f.Area)
+					t.Logf("landmarks[%d]: %s", i, f.RelativeLandmarksJSON())
+				}
+			}
+
+			if i, ok := expected[baseName]; ok {
+				assert.Equal(t, i, faces.Count())
+
+				if faces.Count() == 0 {
+					assert.Equal(t, 100, faces.Uncertainty())
+				} else {
+					assert.Truef(t, faces.Uncertainty() >= 0 && faces.Uncertainty() <= 50, "uncertainty should be between 0 and 50")
+				}
+				t.Logf("uncertainty: %d", faces.Uncertainty())
+			} else {
+				t.Logf("unknown test result for %s", baseName)
+			}
+		})
+
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestDetectOverlap(t *testing.T) {
+	expected := map[string]int{
+		"1.jpg": 2,
+		"2.jpg": 2,
+		"3.jpg": 2,
+		"4.jpg": 1,
+	}
+
+	if err := fastwalk.Walk("testdata/overlap", func(fileName string, info os.FileMode) error {
+		if info.IsDir() || filepath.Base(filepath.Dir(fileName)) != "overlap" {
+			return nil
+		}
+
+		t.Run(fileName, func(t *testing.T) {
+			baseName := filepath.Base(fileName)
+
+			faces, err := Detect(fileName, true, 20)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			t.Logf("found %d faces in '%s'", len(faces), baseName)
+
+			if len(faces) > 0 {
+				// t.Logf("results: %#v", faces)
+
+				for i, f := range faces {
+					t.Logf("marker[%d]: %#v %#v", i, f.CropArea(), f.Area)
+					t.Logf("landmarks[%d]: %s", i, f.RelativeLandmarksJSON())
+				}
+			}
+
+			if i, ok := expected[baseName]; ok {
+				assert.Equal(t, i, faces.Count())
+
+				if faces.Count() == 0 {
+					assert.Equal(t, 100, faces.Uncertainty())
+				} else {
+					assert.Truef(t, faces.Uncertainty() >= 0 && faces.Uncertainty() <= 50, "uncertainty should be between 0 and 50")
+				}
+				t.Logf("uncertainty: %d", faces.Uncertainty())
+			} else {
+				t.Logf("unknown test result for %s", baseName)
+			}
+		})
+
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/internal/face/face.go b/internal/face/face.go
index 3acc76531..fdad7a648 100644
--- a/internal/face/face.go
+++ b/internal/face/face.go
@@ -39,18 +39,39 @@ import (
 	"github.com/photoprism/photoprism/internal/event"
 )
 
+var log = event.Log
+
 var CropSize = crop.Sizes[crop.Tile160]
 var ClusterCore = 4
 var ClusterRadius = 0.6
-var ClusterMinScore = 30
+var ClusterMinScore = 15
 var ClusterMinSize = 100
 var SampleThreshold = 2 * ClusterCore
-
-var log = event.Log
+var OverlapThreshold = 40
+var OverlapThresholdFloor = OverlapThreshold - 1
+var ScoreThreshold = float32(8.5)
 
 // Faces is a list of face detection results.
 type Faces []Face
 
+// Contains returns true if the face conflicts with existing faces.
+func (faces Faces) Contains(other Face) bool {
+	cropArea := other.CropArea()
+
+	for _, f := range faces {
+		if f.CropArea().OverlapPercent(cropArea) > OverlapThresholdFloor {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Append adds a face.
+func (faces *Faces) Append(f Face) {
+	*faces = append(*faces, f)
+}
+
 // Count returns the number of faces detected.
 func (faces Faces) Count() int {
 	return len(faces)
diff --git a/internal/face/face_test.go b/internal/face/face_test.go
index fad078065..f42ab3708 100644
--- a/internal/face/face_test.go
+++ b/internal/face/face_test.go
@@ -1,159 +1,11 @@
 package face
 
 import (
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"strings"
 	"testing"
 
-	"github.com/photoprism/photoprism/internal/crop"
-
-	"github.com/photoprism/photoprism/pkg/fastwalk"
 	"github.com/stretchr/testify/assert"
 )
 
-var modelPath, _ = filepath.Abs("../../assets/facenet")
-
-func TestDetect(t *testing.T) {
-	expected := map[string]int{
-		"1.jpg":  1,
-		"2.jpg":  1,
-		"3.jpg":  1,
-		"4.jpg":  1,
-		"5.jpg":  1,
-		"6.jpg":  1,
-		"7.jpg":  0,
-		"8.jpg":  0,
-		"9.jpg":  0,
-		"10.jpg": 0,
-		"11.jpg": 0,
-		"12.jpg": 1,
-		"13.jpg": 0,
-		"14.jpg": 0,
-		"15.jpg": 0,
-		"16.jpg": 1,
-		"17.jpg": 1,
-		"18.jpg": 2,
-		"19.jpg": 0,
-	}
-
-	faceindices := map[string][]int{
-		"18.jpg": {0, 1},
-		"1.jpg":  {2},
-		"4.jpg":  {3},
-		"5.jpg":  {4},
-		"6.jpg":  {5},
-		"2.jpg":  {6},
-		"12.jpg": {7},
-		"16.jpg": {8},
-		"17.jpg": {9},
-		"3.jpg":  {10},
-	}
-
-	faceindexToPersonid := [11]int{
-		0, 1, 1, 1, 2, 0, 1, 0, 0, 1, 0,
-	}
-
-	var embeddings [11][]float32
-
-	faceNet := NewNet(modelPath, "testdata/cache", false)
-
-	if err := faceNet.loadModel(); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := fastwalk.Walk("testdata", func(fileName string, info os.FileMode) error {
-		if info.IsDir() || strings.HasPrefix(filepath.Base(fileName), ".") || strings.Contains(fileName, "cache") {
-			return nil
-		}
-
-		t.Run(fileName, func(t *testing.T) {
-			baseName := filepath.Base(fileName)
-
-			faces, err := Detect(fileName, true, 20)
-
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			t.Logf("found %d faces in '%s'", len(faces), baseName)
-
-			if len(faces) > 0 {
-				// t.Logf("results: %#v", faces)
-
-				for i, f := range faces {
-					t.Logf("marker[%d]: %#v %#v", i, f.CropArea(), f.Area)
-					t.Logf("landmarks[%d]: %s", i, f.RelativeLandmarksJSON())
-
-					img, err := crop.ImageFromThumb(fileName, f.CropArea(), CropSize, false)
-
-					if err != nil {
-						t.Fatal(err)
-					}
-
-					embedding := faceNet.getEmbeddings(img)
-
-					if b, err := json.Marshal(embedding[0]); err != nil {
-						t.Fatal(err)
-					} else {
-						assert.NotEmpty(t, b)
-						// t.Logf("embedding: %#v", string(b))
-					}
-
-					t.Logf("faces: %d %v", i, faceindices[baseName])
-					embeddings[faceindices[baseName][i]] = embedding[0]
-				}
-			}
-
-			if i, ok := expected[baseName]; ok {
-				assert.Equal(t, i, len(faces))
-				assert.Equal(t, i, faces.Count())
-				if faces.Count() == 0 {
-					assert.Equal(t, 100, faces.Uncertainty())
-				} else {
-					assert.Truef(t, faces.Uncertainty() >= 0 && faces.Uncertainty() <= 50, "uncertainty should be between 0 and 50")
-				}
-				t.Logf("uncertainty: %d", faces.Uncertainty())
-			} else {
-				t.Logf("unknown test result for %s", baseName)
-			}
-		})
-
-		return nil
-	}); err != nil {
-		t.Fatal(err)
-	}
-
-	// Distance Matrix
-	correct := 0
-
-	for i := 0; i < len(embeddings); i++ {
-		for j := 0; j < len(embeddings); j++ {
-			if i >= j {
-				continue
-			}
-			dist := EuclidianDistance(embeddings[i], embeddings[j])
-			t.Logf("Dist for %d %d (faces are %d %d) is %f", i, j, faceindexToPersonid[i], faceindexToPersonid[j], dist)
-			if faceindexToPersonid[i] == faceindexToPersonid[j] {
-				if dist < 1.21 {
-					correct += 1
-				}
-			} else {
-				if dist >= 1.21 {
-					correct += 1
-				}
-			}
-		}
-	}
-
-	t.Logf("Correct for %d", correct)
-
-	// there are a few incorrect results
-	// 4 out of 55 with the 1.21 threshold
-	assert.True(t, correct == 51)
-}
-
 func TestFaces_Uncertainty(t *testing.T) {
 	t.Run("maxScore = 310", func(t *testing.T) {
 		f := Faces{Face{Score: 310}, Face{Score: 210}}
@@ -269,3 +121,125 @@ func TestFace_CropArea(t *testing.T) {
 		t.Logf("marker: %#v", f.CropArea())
 	})
 }
+
+func TestFaces_Contains(t *testing.T) {
+	t.Run("Contained", func(t *testing.T) {
+		a := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 125,
+			Area: Area{
+				Name:  "face",
+				Col:   400,
+				Row:   250,
+				Scale: 200,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		b := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 34,
+			Area: Area{
+				Name:  "face",
+				Col:   100,
+				Row:   100,
+				Scale: 50,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		c := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 125,
+			Area: Area{
+				Name:  "face",
+				Col:   125,
+				Row:   125,
+				Scale: 25,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		d := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 125,
+			Area: Area{
+				Name:  "face",
+				Col:   110,
+				Row:   110,
+				Scale: 50,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		faces := Faces{a, b}
+
+		assert.True(t, faces.Contains(a))
+		assert.True(t, faces.Contains(b))
+		assert.False(t, faces.Contains(c))
+		assert.True(t, faces.Contains(d))
+	})
+	t.Run("NotContained", func(t *testing.T) {
+		a := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 125,
+			Area: Area{
+				Name:  "face",
+				Col:   400,
+				Row:   250,
+				Scale: 200,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		b := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 34,
+			Area: Area{
+				Name:  "face",
+				Col:   100,
+				Row:   100,
+				Scale: 50,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		c := Face{
+			Cols:  1000,
+			Rows:  600,
+			Score: 125,
+			Area: Area{
+				Name:  "face",
+				Col:   900,
+				Row:   500,
+				Scale: 25,
+			},
+			Eyes:       nil,
+			Landmarks:  nil,
+			Embeddings: nil,
+		}
+
+		faces := Faces{a}
+
+		assert.False(t, faces.Contains(b))
+		assert.False(t, faces.Contains(c))
+	})
+}
diff --git a/internal/face/net_test.go b/internal/face/net_test.go
index fd73d1883..bbd581c88 100644
--- a/internal/face/net_test.go
+++ b/internal/face/net_test.go
@@ -3,13 +3,14 @@ package face
 import (
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 
 	"github.com/photoprism/photoprism/pkg/fastwalk"
 	"github.com/stretchr/testify/assert"
 )
 
+var modelPath, _ = filepath.Abs("../../assets/facenet")
+
 func TestNet(t *testing.T) {
 	expected := map[string]int{
 		"1.jpg":  1,
@@ -34,7 +35,7 @@ func TestNet(t *testing.T) {
 	}
 
 	faceindices := map[string][]int{
-		"18.jpg": {0, 1},
+		"18.jpg": {1, 0},
 		"1.jpg":  {2},
 		"4.jpg":  {3},
 		"5.jpg":  {4},
@@ -55,7 +56,7 @@ func TestNet(t *testing.T) {
 	faceNet := NewNet(modelPath, "testdata/cache", false)
 
 	if err := fastwalk.Walk("testdata", func(fileName string, info os.FileMode) error {
-		if info.IsDir() || strings.HasPrefix(filepath.Base(fileName), ".") || strings.Contains(fileName, "cache") {
+		if info.IsDir() || filepath.Base(filepath.Dir(fileName)) != "testdata" {
 			return nil
 		}
 
@@ -68,11 +69,11 @@ func TestNet(t *testing.T) {
 				t.Fatal(err)
 			}
 
-			t.Logf("found %d faces in '%s'", len(faces), baseName)
+			// for i, f := range faces {
+			// 	t.Logf("FACE %d IN %s: %#v", i, fileName, f.Area)
+			// }
 
 			if len(faces) > 0 {
-				// t.Logf("results: %#v", faces)
-
 				for i, f := range faces {
 					if len(f.Embeddings) > 0 {
 						embeddings[faceindices[baseName][i]] = f.Embeddings[0]
@@ -83,8 +84,8 @@ func TestNet(t *testing.T) {
 			}
 
 			if i, ok := expected[baseName]; ok {
-				assert.Equal(t, i, len(faces))
 				assert.Equal(t, i, faces.Count())
+
 				if faces.Count() == 0 {
 					assert.Equal(t, 100, faces.Uncertainty())
 				} else {
@@ -127,5 +128,5 @@ func TestNet(t *testing.T) {
 
 	// there are a few incorrect results
 	// 4 out of 55 with the 1.21 threshold
-	assert.True(t, correct == 51)
+	assert.Equal(t, 51, correct)
 }
diff --git a/internal/face/testdata/overlap/1.jpg b/internal/face/testdata/overlap/1.jpg
new file mode 100644
index 000000000..fb7831493
Binary files /dev/null and b/internal/face/testdata/overlap/1.jpg differ
diff --git a/internal/face/testdata/overlap/2.jpg b/internal/face/testdata/overlap/2.jpg
new file mode 100644
index 000000000..1f281e7d4
Binary files /dev/null and b/internal/face/testdata/overlap/2.jpg differ
diff --git a/internal/face/testdata/overlap/3.jpg b/internal/face/testdata/overlap/3.jpg
new file mode 100644
index 000000000..03298b266
Binary files /dev/null and b/internal/face/testdata/overlap/3.jpg differ
diff --git a/internal/face/testdata/overlap/4.jpg b/internal/face/testdata/overlap/4.jpg
new file mode 100644
index 000000000..1d82519ac
Binary files /dev/null and b/internal/face/testdata/overlap/4.jpg differ