在应用软件开发中，图片数据，对于一个公司来说是十分重要的，例如：上传图片资料，修改用户头像等，而这其中就离不开相机和相册的使用。对于ios平台来说，直接调用系统相机或相册，就可搞定一切。然而对于Android平台来说，直接调用系统相机或相册，在适配和体验上问题比较多，具体原因，相比大家也知道，安卓品牌太多太杂，性能不一。鉴于此，在开发的过程中，遇到类似问题，建议自己实现相机或相册功能，以保证体验完整。本篇博文将会重点介绍Camera相机的实现。
首先，推荐两个github项目，可以直接使用的相机和相册；另外，也推荐一个联系人选择器：
相机：CameraDemo(自定义相机)
相册：ImageSelector(仿微信图片选择相册)
联系人：ContactSelector(联系人选择器)
一、打开Camera
try {
mCamera = Camera.open();//开启相机
} catch (RuntimeException e) {
e.printStackTrace();
LogUtil.d(TAG, "摄像头异常，请检查摄像头权限是否应许");
ToastUtil.getInstance().toast("摄像头异常，请检查摄像头权限是否应许");
return;
}二、设置Camera参数
默认尺寸可以自由设置，这里取手机的分辨率为默认尺寸。
1.根据指定分辨率查找相机最佳适配分辨率并设置
private void setCameraParams(int width, int height) {
LogUtil.i(TAG, "setCameraParams width=" + width + " height=" + height);
Camera.Parameters parameters = mCamera.getParameters();
List<Camera.Size> pictureSizeList = parameters.getSupportedPictureSizes();
sort(pictureSizeList);//排序
for (Camera.Size size : pictureSizeList) {
LogUtil.i(TAG, "摄像头支持的分辨率：" + " size.width=" + size.width + " size.height=" + size.height);
}
Camera.Size picSize = getBestSupportedSize(pictureSizeList, ((float) height / width));//从列表中选取合适的分辨率
if (null == picSize) {
picSize = parameters.getPictureSize();
}
LogUtil.e(TAG, "我们选择的摄像头分辨率：" + "picSize.width=" + picSize.width + " picSize.height=" + picSize.height);
// 根据选出的PictureSize重新设置SurfaceView大小
parameters.setPictureSize(picSize.width, picSize.height);
....2.根据指定分辨率查找相机最佳预览分辨率并设置
private void setCameraParams(int width, int height) {
LogUtil.i(TAG, "setCameraParams width=" + width + " height=" + height);
Camera.Parameters parameters = mCamera.getParameters();
/*************************** 获取摄像头支持的PreviewSize列表********************/
List<Camera.Size> previewSizeList = parameters.getSupportedPreviewSizes();
sort(previewSizeList);
for (Camera.Size size : previewSizeList) {
LogUtil.i(TAG, "摄像支持可预览的分辨率：" + " size.width=" + size.width + " size.height=" + size.height);
}
Camera.Size preSize = getBestSupportedSize(previewSizeList, ((float) height) / width);
if (null != preSize) {
LogUtil.e(TAG, "我们选择的预览分辨率：" + "preSize.width=" + preSize.width + " preSize.height=" + preSize.height);
parameters.setPreviewSize(preSize.width, preSize.height);
}
......3.最佳分辨率适配算法(先排序)
/**
* 如包含默认尺寸，则选默认尺寸，如没有，则选最大的尺寸
* 规则：在相同比例下，1.优先寻找长宽分辨率相同的->2.找长宽有一个相同的分辨率->3.找最大的分辨率
*
* @param sizes 尺寸集合
* @return 返回合适的尺寸
*/
private Camera.Size getBestSupportedSize(List<Camera.Size> sizes, float screenRatio) {
Camera.Size largestSize = null;
int largestArea = 0;
for (Camera.Size size : sizes) {
if ((float) size.height / (float) size.width == screenRatio) {
if (size.width == DEFAULT_PHOTO_WIDTH && size.height == DEFAULT_PHOTO_HEIGHT) {
// 包含特定的尺寸，直接取该尺寸
largestSize = size;
break;
} else if (size.height == DEFAULT_PHOTO_HEIGHT || size.width == DEFAULT_PHOTO_WIDTH) {
largestSize = size;
break;
}
int area = size.height + size.width;
if (area > largestArea) {//找出最大的合适尺寸
largestArea = area;
largestSize = size;
}
} else if (size.height == DEFAULT_PHOTO_HEIGHT || size.width == DEFAULT_PHOTO_WIDTH) {
largestSize = size;
break;
}
}
if (largestSize == null) {
largestSize = sizes.get(sizes.size() - 1);
}
return largestSize;
}4.对焦模式选择
由于部分智能手机，前置摄像头无对焦模式，对焦参数设置应区分前置摄像头
//对焦模式的选择
if(cameraId == Camera.CameraInfo.CAMERA_FACING_BACK){
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);//手动区域自动对焦
}5.图片质量
PixelFormat中有多种模式，源码有解。
//图片质量
parameters.setJpegQuality(100); // 设置照片质量
parameters.setPreviewFormat(PixelFormat.YCbCr_420_SP); // 预览格式
parameters.setPictureFormat(PixelFormat.JPEG); // 相片格式为JPEG，默认为NV216.闪关灯及横竖屏镜头调整
// 关闪光灯
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
// 横竖屏镜头自动调整
if (mContext.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
mCamera.setDisplayOrientation(90);
} else {
mCamera.setDisplayOrientation(0);
}7.相机异常监听
//相机异常监听
mCamera.setErrorCallback(new Camera.ErrorCallback() {
@Override
public void onError(int error, Camera camera) {
String error_str;
switch (error) {
case Camera.CAMERA_ERROR_SERVER_DIED: // 摄像头已损坏
error_str = "摄像头已损坏";
break;
case Camera.CAMERA_ERROR_UNKNOWN:
error_str = "摄像头异常，请检查摄像头权限是否应许";
break;
default:
error_str = "摄像头异常，请检查摄像头权限是否应许";
break;
}
ToastUtil.getInstance().toast(error_str);
Log.i(TAG, error_str);
}
});完整参数设置代码：
/**
* 设置分辨率等参数
*
* @param width 宽
* @param height 高
*/
private void setCameraParams(int width, int height) {
LogUtil.i(TAG, "setCameraParams width=" + width + " height=" + height);
Camera.Parameters parameters = mCamera.getParameters();
/*************************** 获取摄像头支持的PictureSize列表********************/
List<Camera.Size> pictureSizeList = parameters.getSupportedPictureSizes();
sort(pictureSizeList);//排序
for (Camera.Size size : pictureSizeList) {
LogUtil.i(TAG, "摄像头支持的分辨率：" + " size.width=" + size.width + " size.height=" + size.height);
}
Camera.Size picSize = getBestSupportedSize(pictureSizeList, ((float) height / width));//从列表中选取合适的分辨率
if (null == picSize) {
picSize = parameters.getPictureSize();
}
LogUtil.e(TAG, "我们选择的摄像头分辨率：" + "picSize.width=" + picSize.width + " picSize.height=" + picSize.height);
// 根据选出的PictureSize重新设置SurfaceView大小
parameters.setPictureSize(picSize.width, picSize.height);
/*************************** 获取摄像头支持的PreviewSize列表********************/
List<Camera.Size> previewSizeList = parameters.getSupportedPreviewSizes();
sort(previewSizeList);
for (Camera.Size size : previewSizeList) {
LogUtil.i(TAG, "摄像支持可预览的分辨率：" + " size.width=" + size.width + " size.height=" + size.height);
}
Camera.Size preSize = getBestSupportedSize(previewSizeList, ((float) height) / width);
if (null != preSize) {
LogUtil.e(TAG, "我们选择的预览分辨率：" + "preSize.width=" + preSize.width + " preSize.height=" + preSize.height);
parameters.setPreviewSize(preSize.width, preSize.height);
}
/*************************** 对焦模式的选择 ********************/
if(cameraId == Camera.CameraInfo.CAMERA_FACING_BACK){
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);//手动区域自动对焦
}
//图片质量
parameters.setJpegQuality(100); // 设置照片质量
parameters.setPreviewFormat(PixelFormat.YCbCr_420_SP); // 预览格式
parameters.setPictureFormat(PixelFormat.JPEG); // 相片格式为JPEG，默认为NV21
// 关闪光灯
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
// 横竖屏镜头自动调整
if (mContext.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
mCamera.setDisplayOrientation(90);
} else {
mCamera.setDisplayOrientation(0);
}
//相机异常监听
mCamera.setErrorCallback(new Camera.ErrorCallback() {
@Override
public void onError(int error, Camera camera) {
String error_str;
switch (error) {
case Camera.CAMERA_ERROR_SERVER_DIED: // 摄像头已损坏
error_str = "摄像头已损坏";
break;
case Camera.CAMERA_ERROR_UNKNOWN:
error_str = "摄像头异常，请检查摄像头权限是否应许";
break;
default:
error_str = "摄像头异常，请检查摄像头权限是否应许";
break;
}
ToastUtil.getInstance().toast(error_str);
Log.i(TAG, error_str);
}
});
mCamera.cancelAutoFocus();
mCamera.setParameters(parameters);
}三、对焦
要实现点击对焦，并有对焦环，需要自定义实现对焦环View.
1.自定义对焦环View-CameraFocusView
核心功能，就是对焦环缩小，并变绿。利用动画改变对焦环半径即可。
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(isShow){
if(radius == GREEN_RADIUS){
mPaint.setColor(Color.GREEN);
}
if(centerPoint!=null){
canvas.drawCircle(centerPoint.x, centerPoint.y, radius, mPaint);
}
}
}
private void showAnimView() {
isShow = true;
if (lineAnimator == null) {
lineAnimator = ValueAnimator.ofInt(0, 20);
lineAnimator.setDuration(DURATION_TIME);
lineAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int animationValue = (Integer) animation
.getAnimatedValue();
if(lastValue!=animationValue&&radius>=(int) ((mScreenWidth * 0.1)-20)){
radius = radius - animationValue;
lastValue = animationValue;
}
isShow = true;
invalidate();
}
});
lineAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
isShow = false;
lastValue = 0;
mPaint.setColor(Color.WHITE);
radius = (int) (mScreenWidth * 0.1);
invalidate();
}
});
}else{
lineAnimator.end();
lineAnimator.cancel();
lineAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
lineAnimator.start();
}
}2.布局界面
让对焦环自定义View获取整个界面的触摸事件
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.awen.camera.widget.CameraSurfaceView
android:id="@+id/cameraSurfaceView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<com.awen.camera.widget.CameraFocusView
android:id="@+id/cameraFocusView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
......3.定义对焦接口
i.定义接口
/**
* 聚焦的回调接口
*/
public interface IAutoFocus {
void autoFocus(float x,float y);
}ii.对焦环View触摸事件中触发接口：
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
int x = (int) event.getX();
int y = (int) event.getY();
lastValue = 0;
mPaint.setColor(Color.WHITE);
radius = (int) (mScreenWidth * 0.1);
centerPoint = null;
if(y>TOP_CONTROL_HEIGHT&&y<ScreenSizeUtil.getScreenHeight()-BETTOM_CONTROL_HEIGHT){//状态栏和底部禁止点击获取焦点（显示体验不好）
centerPoint = new Point(x, y);
showAnimView();
//开始对焦
if (mIAutoFocus != null) {
mIAutoFocus.autoFocus(event.getX(),event.getY());
}
}
break;
}
return true;
}4.在CameraSurfaceView实现对焦
i.计算对焦区域
private Rect caculateFocusPoint(int x, int y) {
Rect rect = new Rect(x - 100, y - 100, x + 100, y + 100);
int left = rect.left * 2000 / getWidth() - 1000;
int top = rect.top * 2000 / getHeight() - 1000;
int right = rect.right * 2000 / getWidth() - 1000;
int bottom = rect.bottom * 2000 / getHeight() - 1000;
// 如果超出了(-1000,1000)到(1000, 1000)的范围，则会导致相机崩溃
left = left < -1000 ? -1000 : left;
top = top < -1000 ? -1000 : top;
right = right > 1000 ? 1000 : right;
bottom = bottom > 1000 ? 1000 : bottom;
return new Rect(left, top, right, bottom);
}ii.设置参数进行对焦
private void camerFocus(Rect rect) {
if (mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
if(cameraId == Camera.CameraInfo.CAMERA_FACING_BACK){
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);//手动区域自动对焦
}
if (parameters.getMaxNumFocusAreas() > 0) {
List<Camera.Area> focusAreas = new ArrayList<Camera.Area>();
focusAreas.add(new Camera.Area(rect, 1000));
parameters.setFocusAreas(focusAreas);
}
mCamera.cancelAutoFocus(); // 先要取消掉进程中所有的聚焦功能
mCamera.setParameters(parameters);
mCamera.autoFocus(this);
}四、拍照
为了图片方便预览，需要对图片进行处理，所以需要知道相机的拍照时的方向，故在拍照应先设置照片的方向参数
1.CameraOrientationDetector(Camera方向监听器)
/**
* 方向变化监听器，监听传感器方向的改变
* Created by AwenZeng on 2017/2/21.
*/
public class CameraOrientationDetector extends OrientationEventListener {
int mOrientation;
public CameraOrientationDetector(Context context, int rate) {
super(context, rate);
}
@Override
public void onOrientationChanged(int orientation) {
this.mOrientation = orientation;
if (orientation == OrientationEventListener.ORIENTATION_UNKNOWN) {
return;
}
//保证只返回四个方向,分别为0°、90°、180°和270°中的一个
int newOrientation = ((orientation + 45) / 90 * 90) % 360;
if (newOrientation != mOrientation) {
mOrientation = newOrientation;
}
}
public int getOrientation() {
return mOrientation;
}
}2.设置照片方向参数
/**
* 拍照
*
* @param callback
*/
public void takePicture(Camera.PictureCallback callback) {
if (mCamera != null) {
int orientation = mCameraOrientation.getOrientation();
Camera.Parameters cameraParameter = mCamera.getParameters();
if (orientation == 90) {
cameraParameter.setRotation(90);
cameraParameter.set("rotation", 90);
} else if (orientation == 180) {
cameraParameter.setRotation(180);
cameraParameter.set("rotation", 180);
} else if (orientation == 270) {
cameraParameter.setRotation(270);
cameraParameter.set("rotation", 270);
} else {
cameraParameter.setRotation(0);
cameraParameter.set("rotation", 0);
}
mCamera.setParameters(cameraParameter);
}
mCamera.takePicture(null, null, callback);
}3.保存图片
为了方便预览，对不同方向的图片，需要做正向处理。
public String handlePhoto(byte[] data, int cameraId) {
String filePath = FileUtil.saveFile(data, "/DCIM");
if (!TextUtils.isEmpty(filePath)) {
int degree = BitmapUtil.getPhotoDegree(filePath);
Log.i(TAG, degree + "");
Bitmap bitmap = BitmapFactory.decodeFile(filePath);
Bitmap tBitmap = null;
try {
Log.i(TAG, "保存图片大小："+"width = " + bitmap.getWidth() + " ------ height = " + bitmap.getHeight());
if (cameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
switch (degree) {
case 0:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 90);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 90:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 180);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 180:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 270);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 270:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 360);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
}
} else if (cameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
switch (degree) {
case 0:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 270);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 90:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 180);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 180:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 90);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
case 270:
tBitmap = BitmapUtil.rotateBitmap(bitmap, 360);
filePath = BitmapUtil.saveBitmap(tBitmap == null ? bitmap : tBitmap, filePath);
break;
}
}
} catch (Exception e) {
e.printStackTrace();
// 重新拍照
return "";
} finally {
if (bitmap != null) {
bitmap.recycle();
bitmap = null;
}
if (tBitmap != null) {
tBitmap.recycle();
tBitmap = null;
}
ScannerByReceiver(mContext, filePath);//图库扫描
}
return filePath;
}
return null;
}五、切换摄像头
/**
* 切换摄像头
*/
public void changeCamera(int camera_id) {
mCamera.stopPreview();
mCamera.release();
try {
openCamera(camera_id);
mCamera.setPreviewDisplay(holder);
setCameraParams(DEFAULT_PHOTO_WIDTH, DEFAULT_PHOTO_HEIGHT);
mCamera.startPreview();
} catch (Exception e) {
e.printStackTrace();
}
}
public boolean openCamera(int camera_id) {
LogUtil.i(TAG, "openCamera id = " + camera_id);
try {
mCamera = Camera.open(camera_id); // 打开摄像头
cameraId = camera_id;
} catch (Exception e) {
e.printStackTrace();
ToastUtil.getInstance().toast("请先开启摄像头权限");
LogUtil.i(TAG, "请先开启摄像头权限");
return false;
}
return true;
}六、打开或关闭闪光灯
/**
* 设置闪光灯
*
* @param isOpen
*/
public void changeFlashMode(boolean isOpen, Camera mCamera, int cameraId) {
if (cameraId == Camera.CameraInfo.CAMERA_FACING_BACK) { // 后摄像头才有闪光灯
Camera.Parameters parameters = mCamera.getParameters();
PackageManager pm = mContext.getPackageManager();
FeatureInfo[] features = pm.getSystemAvailableFeatures();
for (FeatureInfo f : features) {
if (PackageManager.FEATURE_CAMERA_FLASH.equals(f.name)) { // 判断设备是否支持闪光灯
if (isOpen) {
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH); // 开闪光灯
} else {
parameters
.setFlashMode(Camera.Parameters.FLASH_MODE_OFF); // 关闪光灯
}
}
}
mCamera.setParameters(parameters);
}
}注意事项
- Android6.0以上权限收紧，所以在使用相机前，请用PermissionsModel做好权限判断。
- 部分智能手机，前置摄像头无对焦模式，对焦参数设置应区分前置摄像头
- Android5.0以后，官方推荐使用Camera2,本例子未使用新版本。
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