如何在Camera2 API Android中捕获覆盖层内的图像？

Question

我只需要捕获如图所示的覆盖框内的图像。我不需要TextureView 中的整个图像。我是 Android 新手，我无法找出一些提到的仅捕获矩形区域内图像的解决方案。覆盖层必须位于中心。我尝试过，但没能实现。

我遵循了这段代码 - Google Sample-Camera2Basic

---

为了添加覆盖，我使用了以下代码：

activity_camera2_basic_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.example.googlecamera2.AutoFitTextureView
        android:id="@+id/texture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true" />

    <LinearLayout
        android:id="@+id/surface"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_centerInParent="true"/>

    <FrameLayout
        android:id="@+id/control"
        android:layout_width="match_parent"
        android:layout_height="112dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:background="@color/control_background">

        <Button
            android:id="@+id/picture"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="@string/picture" />

        <ImageButton
            android:id="@+id/info"
            android:contentDescription="@string/description_info"
            style="@android:style/Widget.Material.Light.Button.Borderless"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical|right"
            android:padding="20dp"
            android:src="@drawable/ic_action_info" />

    </FrameLayout>

</RelativeLayout>

---

我是onCreateView这样实现的：

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_camera2_basic, container, false);

        linearLayout = view.findViewById(R.id.surface);
        linearLayout.addView(new Rectangle(getActivity()));
        return view;
    }

编辑

矩形.java

package com.example.googlecamera2;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.view.View;

public class Rectangle extends View {
    Paint paint = new Paint();

    public Rectangle(Context context) {
        super(context);
    }


    @Override
    public void onDraw(Canvas canvas) {
        paint.setColor(Color.GREEN);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(6);
        Rect rect = new Rect(120, 100, 620, 900);
        canvas.drawRect(rect, paint );
    }
}

请建议我如何从叠加区域中获取裁剪后的图像并将叠加在预览中居中。

Answer 1

我最初创建了一个位图，比如说capturedBitmap。这是相机捕获的原始位图。

capturedImage = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

然后我必须找到覆盖层的确切坐标。

// Set the left, top, width and height of the overlay to get that portion of the image.
// Also, rotate the image i.e., rotationMatrix

croppedImage = Bitmap.createBitmap(capturedImage, left, top, cropWidth, cropHeight, rotationMatrix, false);