【发布时间】：2021-07-24 03:17:18
【问题描述】：
我有一个简单的布局：
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:tools="http://schemas.android.com/tools"
android:background="#FF000000"
app:layout_constraintDimensionRatio="3:4"
tools:context=".pkgActivity.CameraImp">
<RelativeLayout
android:id="@+id/myP"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintDimensionRatio="3:4"
>
<androidx.camera.view.PreviewView
android:id="@+id/camera"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="@string/preview_area"
android:importantForAccessibility="no">
</androidx.camera.view.PreviewView>
<ImageView
android:id="@+id/foundObject"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="@string/pic_desc"
android:visibility="visible" />
<ImageView
android:id="@+id/captureImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
app:layout_constraintDimensionRatio="3:4"
android:scaleX="-1"
android:contentDescription="@string/capture"
android:src="@mipmap/ic_launcher" />
<Button
android:id="@+id/buttonGalleryImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentBottom="true"
android:text="Gallery" />
<Button
android:id="@+id/buttonChangeCamera"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:text="camera" />
<Button
android:id="@+id/buttonGoBackTo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="goback" />
<Button
android:id="@+id/buttonPaper"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="goback" />
</RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
看起来像这样：
如您所见，我有一个 ImageView foundObject，我想用它来显示我从自定义 ImageAnalyzer 收到的找到对象的边框：
public class PaperImageAnalyser implements ImageAnalysis.Analyzer {
ObjectDetectorOptions options = new ObjectDetectorOptions.Builder()
.setDetectorMode(ObjectDetectorOptions.STREAM_MODE)
.enableClassification() // Optional
.build();
ObjectDetector objectDetector = ObjectDetection.getClient(options);
@Override
public void analyze(@NonNull ImageProxy imageProxy) {
@SuppressLint("UnsafeExperimentalUsageError") Image mediaImage = imageProxy.getImage();
if (mediaImage != null) {
InputImage image =InputImage.fromMediaImage(mediaImage, imageProxy.getImageInfo().getRotationDegrees());
objectDetector.process(image)
.addOnSuccessListener(
new OnSuccessListener<List<DetectedObject>>() {
@Override
public void onSuccess(List<DetectedObject> detectedObjects) {
for (DetectedObject detectedObject : detectedObjects) {
Rect boundingBox = detectedObject.getBoundingBox();
Log.e("received",""+ boundingBox);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.RED);
paint.setStrokeWidth(10f);
Canvas canvas = new Canvas();
canvas.drawRect( boundingBox.left, boundingBox.top, boundingBox.right, boundingBox.bottom, paint );
CameraImp.foundObject.draw(canvas); //CameraImp = my fragment, foundObject is the static imageview
}
}
})
.addOnFailureListener(
new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Log.e("error",""+e.getMessage());
}
})
.addOnCompleteListener(new OnCompleteListener<List<DetectedObject>>() {
@SuppressLint("UnsafeExperimentalUsageError")
@Override
public void onComplete(@NonNull Task<List<DetectedObject>> task) {
imageProxy.getImage().close();
imageProxy.close();
}
});
}
}
}
问题是我收到了被识别的对象，例如：
E/received: Rect(233, 0 - 720, 1309)
E/received: Rect(237, 0 - 720, 1307)
E/received: Rect(235, 0 - 720, 1304)
E/received: Rect(233, 0 - 720, 1303)
E/received: Rect(229, 0 - 720, 1299)
E/received: Rect(222, 0 - 720, 1293)
E/received: Rect(214, 0 - 720, 1289)
E/received: Rect(207, 0 - 720, 1285)
E/received: Rect(203, 0 - 720, 1285)
E/received: Rect(201, 0 - 720, 1287)
E/received: Rect(201, 0 - 720, 1290)
E/received: Rect(204, 0 - 720, 1294)
E/received: Rect(208, 0 - 720, 1297)
E/received: Rect(210, 0 - 720, 1294)
E/received: Rect(199, 0 - 720, 1271)
E/received: Rect(212, 0 - 720, 1219)
但 ImageView 不显示对象的形状。
问题是原因是什么。是因为我从自定义 ImageAnalyzer 收到了错误的尺寸，还是因为我绘制了错误的形状？
【问题讨论】：
标签： android canvas imageview android-camerax google-mlkit