Antigravity Agent
5.0 KiB
5.0 KiB
id, title, category, status, source_trust_level, verification_status, created_at, updated_at, tags, tech_stack, applied_in, aliases
| id | title | category | status | source_trust_level | verification_status | created_at | updated_at | tags | tech_stack | applied_in | aliases | ||||||||||||||
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| android-camerax-patterns | Android CameraX — 카메라 / 이미지 분석 | Coding | draft | B | conceptual | 2026-05-09 | 2026-05-09 |
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Android CameraX
Camera2 의 lifecycle-aware wrapper. Preview / ImageCapture / ImageAnalysis / VideoCapture 4종 use case. 디바이스 호환성 자동 처리.
📖 핵심 개념
- ProcessCameraProvider: 부팅.
- UseCase: Preview / ImageCapture / ImageAnalysis / VideoCapture.
- bindToLifecycle: lifecycle 에 묶어 자동 시작/정지.
💻 코드 패턴
의존성
implementation("androidx.camera:camera-core:1.4.0")
implementation("androidx.camera:camera-camera2:1.4.0")
implementation("androidx.camera:camera-lifecycle:1.4.0")
implementation("androidx.camera:camera-view:1.4.0")
Preview + Capture (Compose)
@Composable
fun CameraScreen() {
val ctx = LocalContext.current
val lifecycleOwner = LocalLifecycleOwner.current
val previewView = remember { PreviewView(ctx) }
var imageCapture by remember { mutableStateOf<ImageCapture?>(null) }
LaunchedEffect(Unit) {
val provider = ProcessCameraProvider.getInstance(ctx).get()
val preview = Preview.Builder().build().also {
it.setSurfaceProvider(previewView.surfaceProvider)
}
val capture = ImageCapture.Builder()
.setCaptureMode(ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY)
.build()
imageCapture = capture
try {
provider.unbindAll()
provider.bindToLifecycle(
lifecycleOwner,
CameraSelector.DEFAULT_BACK_CAMERA,
preview, capture
)
} catch (e: Exception) { log.error("camera bind failed", e) }
}
Box {
AndroidView(factory = { previewView })
Button(onClick = { imageCapture?.takePictureToDisk(ctx) }) { Text("촬영") }
}
}
fun ImageCapture.takePictureToDisk(ctx: Context) {
val file = File(ctx.cacheDir, "shot_${System.currentTimeMillis()}.jpg")
val output = ImageCapture.OutputFileOptions.Builder(file).build()
takePicture(output, ContextCompat.getMainExecutor(ctx),
object : ImageCapture.OnImageSavedCallback {
override fun onImageSaved(o: ImageCapture.OutputFileResults) { /* file ready */ }
override fun onError(e: ImageCaptureException) { log.error("capture failed", e) }
})
}
ImageAnalysis — ML / barcode
val analyzer = ImageAnalysis.Builder()
.setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
.build()
.also {
it.setAnalyzer(Executors.newSingleThreadExecutor()) { imageProxy ->
val mediaImage = imageProxy.image ?: return@setAnalyzer
val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
barcodeScanner.process(image)
.addOnSuccessListener { codes -> codes.forEach { onScan(it.rawValue) } }
.addOnCompleteListener { imageProxy.close() } // 반드시 close
}
}
provider.bindToLifecycle(lifecycleOwner, CameraSelector.DEFAULT_BACK_CAMERA, preview, analyzer)
Permission
val permission = rememberPermissionState(Manifest.permission.CAMERA)
LaunchedEffect(Unit) { permission.launchPermissionRequest() }
if (!permission.status.isGranted) return // PermissionRationale UI
Video capture
val recorder = Recorder.Builder()
.setQualitySelector(QualitySelector.from(Quality.HD))
.build()
val videoCapture = VideoCapture.withOutput(recorder)
provider.bindToLifecycle(lifecycleOwner, selector, preview, videoCapture)
val output = MediaStoreOutputOptions.Builder(...).build()
recording = videoCapture.output.prepareRecording(ctx, output)
.start(ContextCompat.getMainExecutor(ctx)) { event -> ... }
// 종료
recording?.stop()
🤔 의사결정 기준
| 사용 | UseCase 조합 |
|---|---|
| 단순 사진 | Preview + ImageCapture |
| QR / barcode 스캔 | Preview + ImageAnalysis |
| ML 분석 (얼굴, OCR) | Preview + ImageAnalysis |
| 비디오 녹화 | Preview + VideoCapture |
| 사진 + 비디오 동시 | Preview + ImageCapture + VideoCapture (제한 있음) |
❌ 안티패턴
- imageProxy.close() 누락: backpressure → analyzer 멈춤.
- lifecycle 안 묶음: 백그라운드에서 카메라 점유 → 배터리.
- 메인 스레드에서 ML 처리: UI 멈춤. 별도 executor.
- 여러 use case 가 디바이스 한계 초과: bind 실패. 한 번에 적게.
- Preview rotation 안 처리: 회전 시 이상.
- 권한 거부 후 silent: 가이드 UI.
🤖 LLM 활용 힌트
- CameraX + lifecycle bind + 단일 executor analyzer 패턴 표준.
- ML Kit 결합 자주.