建设网站的4个根目录被删,鲁谷做网站的公司,金融投资公司网站模板,下载中心官方网站建设银行1. 相机坐标说明
触摸对焦需要通过setFocusAreas()设置对焦区域#xff0c;而该方法的参数的坐标#xff0c;与屏幕坐标并不相同#xff0c;需要做一个转换。
对Camera#xff08;旧版相机API#xff09;来说#xff0c;相机的坐标区域是一个2000*2000#xff0c;原点…1. 相机坐标说明
触摸对焦需要通过setFocusAreas()设置对焦区域而该方法的参数的坐标与屏幕坐标并不相同需要做一个转换。
对Camera旧版相机API来说相机的坐标区域是一个2000*2000原点在中心区域该区域与相机预览画面的边界重合如下图所示 谷歌的文档对getFocusAreas()方法的描述如下文档连接 Gets the current focus areas. Camera driver uses the areas to decide focus. Before using this API or setFocusAreas(java.util.List), apps should call getMaxNumFocusAreas() to know the maximum number of focus areas first. If the value is 0, focus area is not supported. Each focus area is a rectangle with specified weight. The direction is relative to the sensor orientation, that is, what the sensor sees. The direction is not affected by the rotation or mirroring of Camera.setDisplayOrientation(int). Coordinates of the rectangle range from -1000 to 1000. (-1000, -1000) is the upper left point. (1000, 1000) is the lower right point. The width and height of focus areas cannot be 0 or negative. The weight must range from 1 to 1000. The weight should be interpreted as a per-pixel weight - all pixels in the area have the specified weight. This means a small area with the same weight as a larger area will have less influence on the focusing than the larger area. Focus areas can partially overlap and the driver will add the weights in the overlap region. A special case of a null focus area list means the driver is free to select focus targets as it wants. For example, the driver may use more signals to select focus areas and change them dynamically. Apps can set the focus area list to null if they want the driver to completely control focusing. Focus areas are relative to the current field of view (getZoom()). No matter what the zoom level is, (-1000,-1000) represents the top of the currently visible camera frame. The focus area cannot be set to be outside the current field of view, even when using zoom. Focus area only has effect if the current focus mode is FOCUS_MODE_AUTO, FOCUS_MODE_MACRO, FOCUS_MODE_CONTINUOUS_VIDEO, or FOCUS_MODE_CONTINUOUS_PICTURE. 同时设置测光区域setMeteringAreas()的方法参数的坐标跟对焦区域的坐标是一样的文档对getMeteringAreas()的描述如下文档连接 Gets the current metering areas. Camera driver uses these areas to decide exposure. Before using this API or setMeteringAreas(java.util.List), apps should call getMaxNumMeteringAreas() to know the maximum number of metering areas first. If the value is 0, metering area is not supported. Each metering area is a rectangle with specified weight. The direction is relative to the sensor orientation, that is, what the sensor sees. The direction is not affected by the rotation or mirroring of Camera.setDisplayOrientation(int). Coordinates of the rectangle range from -1000 to 1000. (-1000, -1000) is the upper left point. (1000, 1000) is the lower right point. The width and height of metering areas cannot be 0 or negative. The weight must range from 1 to 1000, and represents a weight for every pixel in the area. This means that a large metering area with the same weight as a smaller area will have more effect in the metering result. Metering areas can partially overlap and the driver will add the weights in the overlap region. A special case of a null metering area list means the driver is free to meter as it chooses. For example, the driver may use more signals to select metering areas and change them dynamically. Apps can set the metering area list to null if they want the driver to completely control metering. Metering areas are relative to the current field of view (getZoom()). No matter what the zoom level is, (-1000,-1000) represents the top of the currently visible camera frame. The metering area cannot be set to be outside the current field of view, even when using zoom. No matter what metering areas are, the final exposure are compensated by setExposureCompensation(int). 2. 坐标转换
根据前面对相机坐标的说明对坐标进行转换就很简单了。
我采用的方法是计算坐标到左上角的x、y方向的距离与x、y轴长度的百分比然后乘以新坐标的x、y轴长度再根据原点与左上角的位置计算坐标。核心代码如下
transX (x / xMax) * 2000 - 1000
trnasY (y / yMax) * 2000 - 1000如果设置了预览画面的旋转角度camera.setDisplayOrientation(orientation)由于触摸事件中MotionEvent对象传递的是屏幕坐标所以需要旋转。为了方便选择在相机坐标下旋转代码如下
Matrix matrix new Matrix();
matrix.setRotate(orientation);
matrix.mapRect(rectF); // rectF是相机坐标下的矩形完整的工具类CameraAreaUtils.java代码如下
package com.example.study.utils;import android.graphics.Matrix;
import android.graphics.Rect;
import android.graphics.RectF;import com.example.study.entities.CameraAreaEntity;public class CameraAreaUtils {/*** 相机坐标区域是2000*2000坐标原点在最中心*/private static final int CAMERA_COORDINATE_SIZE 2000;/*** 原点到边界的距离*/private static final int CAMERA_COORDINATE_HALF_SIZE CAMERA_COORDINATE_SIZE 1;/*** 根据中心点、边框边长、边框长度系数创建矩形区域** param areaEntity 矩形区域信息* return 矩形*/public static Rect createRect(CameraAreaEntity areaEntity) {float x areaEntity.getX();float y areaEntity.getY();int previewWidth areaEntity.getPreviewWidth();int previewHeight areaEntity.getPreviewHeight();int sideSize (int) (areaEntity.getAreaSide() * areaEntity.getCoefficient());int left clamp(x - sideSize / 2, 0, previewWidth);int top clamp(y - sideSize / 2, 0, previewHeight);int right clamp(x sideSize / 2, 0, previewWidth);int bottom clamp(y sideSize / 2, 0, previewHeight);if (right - left sideSize) {if (left 0) {right Math.min(sideSize, previewWidth);}if (right previewWidth) {left Math.max(previewWidth - sideSize, 0);}}if (bottom - top sideSize) {if (top 0) {bottom Math.min(sideSize, previewHeight);}if (bottom previewHeight) {top Math.max(previewHeight - sideSize, 0);}}return new Rect(left, top, right, bottom);}/*** 防止坐标越界** param position 坐标* param min 最小值* param max 最大值* return 坐标*/private static int clamp(float position, int min, int max) {int pos Math.round(position);return pos min ? min : pos max ? max : pos;}/*** 屏幕矩形区域转为相机矩形区域** param areaEntity 矩形区域信息* return 相机矩形区域*/public static Rect transToCamera(CameraAreaEntity areaEntity) {Rect rect createRect(areaEntity);return rectFToRect(transToCamera(new RectF(rect), areaEntity));}/*** 屏幕矩形区域转为相机矩形区域** param rectF 屏幕矩形区域* param areaEntity 矩形区域信息* return 相机矩形区域*/public static RectF transToCamera(RectF rectF, CameraAreaEntity areaEntity) {int previewWidth areaEntity.getPreviewWidth();int previewHeight areaEntity.getPreviewHeight();RectF cameraRectF new RectF(transPositionToCameraCoordinate(rectF.left, previewWidth),transPositionToCameraCoordinate(rectF.top, previewHeight),transPositionToCameraCoordinate(rectF.right, previewWidth),transPositionToCameraCoordinate(rectF.bottom, previewHeight));// 预览画面如果有旋转映射到相机坐标后需要把旋转取消才能对应真正的相机坐标Matrix matrix new Matrix();matrix.setRotate(-1 * areaEntity.getOrientation());matrix.mapRect(cameraRectF);return cameraRectF;}/*** 将屏幕坐标转换为相机坐标** param position 屏幕坐标某个方向的坐标值如x* param srcSize 屏幕坐标对应方向的尺寸如width* return 相机坐标下该方向的坐标值*/private static float transPositionToCameraCoordinate(float position, int srcSize) {return (position / srcSize) * CAMERA_COORDINATE_SIZE - CAMERA_COORDINATE_HALF_SIZE;}/*** 相机矩形区域转为屏幕矩形区域** param rect 相机矩形区域* param areaEntity 矩形区域信息* return 屏幕矩形区域*/public static Rect transToScreen(Rect rect, CameraAreaEntity areaEntity) {return rectFToRect(transToScreen(new RectF(rect), areaEntity));}/*** 相机矩形区域转为屏幕矩形区域** param rectF 相机矩形区域* param areaEntity 矩形区域信息* return 屏幕矩形区域*/public static RectF transToScreen(RectF rectF, CameraAreaEntity areaEntity) {int previewWidth areaEntity.getPreviewWidth();int previewHeight areaEntity.getPreviewHeight();// 先把相机坐标按预览的旋转角度进行旋转Matrix matrix new Matrix();matrix.setRotate(areaEntity.getOrientation());matrix.mapRect(rectF);RectF screenRect new RectF(transPositionToScreenCoordinate(rectF.left, previewWidth),transPositionToScreenCoordinate(rectF.top, previewHeight),transPositionToScreenCoordinate(rectF.right, previewWidth),transPositionToScreenCoordinate(rectF.bottom, previewHeight));return screenRect;}/*** 将相机坐标转换为屏幕坐标** param position 相机坐标某个方向的坐标值如x* param srcSize 相机坐标对应方向的尺寸如width* return 屏幕坐标下该方向的坐标值*/private static float transPositionToScreenCoordinate(float position, int srcSize) {return ((position CAMERA_COORDINATE_HALF_SIZE) / CAMERA_COORDINATE_SIZE) * srcSize;}/*** RectF转为Rect** param rectF rectF对象* return rect对象*/private static Rect rectFToRect(RectF rectF) {if (rectF null) {return new Rect(0, 0, 0, 0);}Rect rect new Rect();rect.left (int) rectF.left;rect.top (int) rectF.top;rect.right (int) rectF.right;rect.bottom (int) rectF.bottom;return rect;}
}矩形区域信息类CameraAreaEntity.java:
package com.example.study.entities;public class CameraAreaEntity {/*** x轴坐标*/private float x;/*** y轴坐标*/private float y;/*** 矩形区域边长*/private int areaSide;/*** 矩形区域边长长度系数*/private float coefficient;/*** 预览画面的旋转角度*/private int orientation;/*** 屏幕宽也就是屏幕坐标轴的x轴*/private int previewWidth;/*** 屏幕高也就是屏幕坐标轴的y轴*/private int previewHeight;public float getX() {return x;}public void setX(float x) {this.x x;}public float getY() {return y;}public void setY(float y) {this.y y;}public int getAreaSide() {return areaSide;}public void setAreaSide(int areaSide) {this.areaSide areaSide;}public float getCoefficient() {return coefficient;}public void setCoefficient(float coefficient) {this.coefficient coefficient;}public int getOrientation() {return orientation;}public void setOrientation(int orientation) {this.orientation orientation;}public int getPreviewWidth() {return previewWidth;}public void setPreviewWidth(int previewWidth) {this.previewWidth previewWidth;}public int getPreviewHeight() {return previewHeight;}public void setPreviewHeight(int previewHeight) {this.previewHeight previewHeight;}
}3. 应用于相机
布局文件activity_camera_demo.xml
?xml version1.0 encodingutf-8?
FrameLayout xmlns:androidhttp://schemas.android.com/apk/res/androidandroid:layout_widthmatch_parentandroid:layout_heightmatch_parentSurfaceViewandroid:idid/camera_previewandroid:layout_widthmatch_parentandroid:layout_heightmatch_parent /com.example.study.views.DrawViewandroid:idid/camera_preview_drawandroid:layout_widthmatch_parentandroid:layout_heightmatch_parent /
/FrameLayout绘制对焦框的DrawView.java
package com.example.study.views;import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;import androidx.annotation.Nullable;import java.util.ArrayList;
import java.util.List;public class DrawView extends View {private final Object lock new Object();protected Paint paint;protected int color;private final ListRect rects new ArrayList();private final Listfloat[] dots new ArrayList();public DrawView(Context context) {super(context);}public DrawView(Context context, Nullable AttributeSet attrs) {super(context, attrs);}public void clear() {synchronized (lock) {rects.clear();dots.clear();}postInvalidate();}public void addRect(Rect rect) {synchronized (lock) {rects.add(rect);}}public void addPoint(float x, float y) {synchronized (lock) {dots.add(new float[]{x, y});}}public void setColor(int color) {this.color color;}Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);synchronized (lock) {paint new Paint();paint.setStyle(Paint.Style.STROKE);paint.setColor(color);for (Rect rect : rects) {paint.setStrokeWidth(4);canvas.drawRect(rect, paint);}for (float[] dot : dots) {paint.setStrokeWidth(10);canvas.drawPoint(dot[0], dot[1], paint);}}}
}触摸监听类TouchListener.java
package com.example.study.listeners;import android.graphics.Color;
import android.graphics.Rect;
import android.hardware.Camera;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;import com.example.study.entities.CameraAreaEntity;
import com.example.study.utils.CameraAreaUtils;
import com.example.study.views.DrawView;import java.util.ArrayList;
import java.util.List;public class TouchListener implements View.OnTouchListener {private static final String TAG TouchListener;private static final int AREA_SIDE 210;private int orientation;private int leftMargin;private int topMargin;private Camera camera;private DrawView drawView;public TouchListener(Camera camera, int orientation, DrawView drawView, int leftMargin, int topMargin) {this.camera camera;this.orientation orientation;this.drawView drawView;this.leftMargin leftMargin;this.topMargin topMargin;}Overridepublic boolean onTouch(View view, MotionEvent event) {try {handlerFocusAndMetering(event);} catch (Exception exception) {Log.i(TAG, exception.getMessage());}return true;}private void handlerFocusAndMetering(MotionEvent event) {// 只有一根手指且按下时才设置对焦区域if (event.getPointerCount() ! 1 || event.getActionMasked() ! MotionEvent.ACTION_DOWN) {return;}drawView.clear();drawView.setColor(Color.WHITE);boolean supportSetArea false;CameraAreaEntity areaEntity createAreaEntity(event);drawView.addPoint(areaEntity.getX(), areaEntity.getY());Camera.Parameters parameters camera.getParameters();// 检查是否支持设置对焦区域if (parameters.getMaxNumFocusAreas() 0) {areaEntity.setCoefficient(1.0f);parameters.setFocusAreas(getAreas(areaEntity));// 绘制对焦区域drawView.addRect(CameraAreaUtils.createRect(areaEntity));supportSetArea true;}// 检查是否支持设置测光区域if (parameters.getMaxNumMeteringAreas() 0) {areaEntity.setCoefficient(1.5f);parameters.setMeteringAreas(getAreas(areaEntity));// 绘制测光区域drawView.addRect(CameraAreaUtils.createRect(areaEntity));supportSetArea true;}drawView.setBackgroundColor(Color.TRANSPARENT);drawView.postInvalidate();if (!supportSetArea) {return;}String currentFocusMode parameters.getFocusMode();parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_MACRO);camera.cancelAutoFocus();camera.setParameters(parameters);camera.autoFocus((success, camera) - {drawRealArea(camera, areaEntity);Camera.Parameters params camera.getParameters();params.setFocusMode(currentFocusMode);camera.setParameters(params);});}private CameraAreaEntity createAreaEntity(MotionEvent event) {// adjustSurface调整过左、上边距所以需要加上边距float x event.getX() leftMargin;float y event.getY() topMargin;Camera.Parameters parameters camera.getParameters();Camera.Size previewSize parameters.getPreviewSize();CameraAreaEntity areaEntity new CameraAreaEntity();areaEntity.setX(x);areaEntity.setY(y);areaEntity.setAreaSide(AREA_SIDE);areaEntity.setOrientation(orientation);areaEntity.setPreviewWidth(previewSize.height);areaEntity.setPreviewHeight(previewSize.width);return areaEntity;}private void drawRealArea(Camera camera, CameraAreaEntity areaEntity) {ListCamera.Area focusAreas camera.getParameters().getFocusAreas();if (focusAreas null) {return;}drawView.clear();drawView.setColor(Color.BLUE);for (Camera.Area focusArea : focusAreas) {// previewSize的width和height正好相反Rect rect CameraAreaUtils.transToScreen(focusArea.rect, areaEntity);drawView.addRect(rect);}drawView.setBackgroundColor(Color.TRANSPARENT);drawView.postInvalidate();}private ListCamera.Area getAreas(CameraAreaEntity areaEntity) {ListCamera.Area areas new ArrayList();// weight权重取值范围为1-1000areas.add(new Camera.Area(CameraAreaUtils.transToCamera(areaEntity), 800));return areas;}
}activity类
package com.example.study.activities;import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
import android.graphics.Point;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;
import android.widget.FrameLayout;import androidx.activity.ComponentActivity;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;import com.example.study.R;
import com.example.study.listeners.TouchListener;
import com.example.study.views.DrawView;public class CameraDemoActivity extends ComponentActivity implements Camera.PreviewCallback, SurfaceHolder.Callback {private static final String TAG CameraDemoActivity;private static final int REQUEST_CAMERA 1000;private static final int HEIGHT 1920;private static final int WIDTH 1080;private static final int ORIENTATION 90;private int leftMargin 0;private int topMargin 0;private SurfaceView preview;private DrawView drawView;private Camera camera;private Camera.Parameters parameters;Overrideprotected void onCreate(Nullable Bundle savedInstanceState) {super.onCreate(savedInstanceState);this.setContentView(R.layout.activity_camera_demo);preview findViewById(R.id.camera_preview);drawView findViewById(R.id.camera_preview_draw);adjustSurface(preview);// 检查权限if (checkSelfPermission(Manifest.permission.CAMERA) ! PackageManager.PERMISSION_GRANTED) {requestPermissions(new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA);} else {preview.getHolder().addCallback(this);}}private void adjustSurface(SurfaceView cameraPreview) {FrameLayout.LayoutParams paramSurface (FrameLayout.LayoutParams) cameraPreview.getLayoutParams();if (getSystemService(Context.WINDOW_SERVICE) ! null) {WindowManager windowManager (WindowManager) getSystemService(Context.WINDOW_SERVICE);Display defaultDisplay windowManager.getDefaultDisplay();Point outPoint new Point();defaultDisplay.getRealSize(outPoint);float screenWidth outPoint.x;float screenHeight outPoint.y;float rate;if (screenWidth / (float) WIDTH screenHeight / (float) HEIGHT) {rate screenWidth / (float) WIDTH;int targetHeight (int) (HEIGHT * rate);paramSurface.width FrameLayout.LayoutParams.MATCH_PARENT;paramSurface.height targetHeight;topMargin (int) (-(targetHeight - screenHeight) / 2);if (topMargin 0) {paramSurface.topMargin topMargin;}} else {rate screenHeight / (float) HEIGHT;int targetWidth (int) (WIDTH * rate);paramSurface.width targetWidth;paramSurface.height FrameLayout.LayoutParams.MATCH_PARENT;leftMargin (int) (-(targetWidth - screenWidth) / 2);if (leftMargin 0) {paramSurface.leftMargin leftMargin;}}}}Overridepublic void onRequestPermissionsResult(int requestCode, NonNull String[] permissions, NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode REQUEST_CAMERA grantResults.length 0 grantResults[0] PackageManager.PERMISSION_GRANTED) {preview.getHolder().addCallback(this);surfaceCreated(preview.getHolder());camera.setPreviewCallback(this);camera.startPreview();}}Overridepublic void onPreviewFrame(byte[] data, Camera camera) {Log.i(TAG, 接收到一帧图片);}Overridepublic void surfaceCreated(NonNull SurfaceHolder holder) {try {camera Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);parameters camera.getParameters();// 旋转了90度所以height、width互换parameters.setPictureSize(HEIGHT, WIDTH);parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);parameters.setPictureFormat(ImageFormat.NV21);camera.setPreviewDisplay(holder);camera.setDisplayOrientation(ORIENTATION);camera.setParameters(parameters);preview.setOnTouchListener(new TouchListener(camera, ORIENTATION, drawView, leftMargin, topMargin));} catch (Exception exception) {Log.i(TAG, exception.getMessage());}}Overridepublic void surfaceChanged(NonNull SurfaceHolder holder, int format, int width, int height) {if (camera ! null) {camera.stopPreview();camera.setPreviewCallback(null);camera.startPreview();camera.setPreviewCallback(this);}}Overridepublic void surfaceDestroyed(NonNull SurfaceHolder holder) {if (camera ! null) {camera.stopPreview();camera.setPreviewCallback(null);camera.release();}}
}
