first commit

internal/vision/hash_test.go

@@ -0,0 +1,80 @@
+package vision
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"testing"
+)
+
+func solid(w, h int, c color.Gray) *image.Gray {
+	img := image.NewGray(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			img.SetGray(x, y, c)
+		}
+	}
+	return img
+}
+
+func TestFingerprintIdentical(t *testing.T) {
+	a := solid(120, 80, color.Gray{Y: 40})
+	b := solid(120, 80, color.Gray{Y: 40})
+	if d := Of(a).Distance(Of(b)); d != 0 {
+		t.Fatalf("相同画面应无差异，实际距离 %d", d)
+	}
+	if Of(a).Changed(Of(b), 5) {
+		t.Fatal("相同画面不应判定为变化")
+	}
+}
+
+func TestFingerprintDetectsChange(t *testing.T) {
+	base := solid(120, 80, color.Gray{Y: 20})
+	changed := image.NewGray(image.Rect(0, 0, 120, 80))
+	for y := 0; y < 80; y++ {
+		for x := 60; x < 120; x++ {
+			changed.SetGray(x, y, color.Gray{Y: 250})
+		}
+	}
+	if !Of(changed).Changed(Of(base), 5) {
+		t.Fatal("右半边变白应被判定为变化")
+	}
+}
+
+func TestEncodeJPEGResizesLongEdge(t *testing.T) {
+	src := solid(2000, 400, color.Gray{Y: 128})
+	raw, err := EncodeJPEG(src, 1280, 75)
+	if err != nil {
+		t.Fatalf("编码失败: %v", err)
+	}
+	if len(raw) == 0 {
+		t.Fatal("编码结果为空")
+	}
+	img, err := jpeg.Decode(bytes.NewReader(raw))
+	if err != nil {
+		t.Fatalf("解码失败: %v", err)
+	}
+	b := img.Bounds()
+	if b.Dx() != 1280 {
+		t.Fatalf("长边应缩放到 1280，实际宽 %d", b.Dx())
+	}
+	if b.Dy() != 256 {
+		t.Fatalf("等比缩放后高应为 256，实际 %d", b.Dy())
+	}
+}
+
+func TestEncodeJPEGKeepsSmallImage(t *testing.T) {
+	src := solid(64, 32, color.Gray{Y: 200})
+	raw, err := EncodeJPEG(src, 1280, 75)
+	if err != nil {
+		t.Fatalf("编码失败: %v", err)
+	}
+	img, err := jpeg.Decode(bytes.NewReader(raw))
+	if err != nil {
+		t.Fatalf("解码失败: %v", err)
+	}
+	if img.Bounds().Dx() != 64 {
+		t.Fatalf("小图不应放大，实际宽 %d", img.Bounds().Dx())
+	}
+}