短视频PHP图片优化方法

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

public class MainActivity extends AppCompatActivity {
 
 
private int  MY_PERMISSIONS_REQUEST_CALL_PHONE=1000;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        //得到手机宽高
        wm=(WindowManager) getSystemService(WINDOW_SERVICE);
        WindowHeight=wm.getDefaultDisplay().getHeight();
        WindowWidth=wm.getDefaultDisplay().getWidth();
        iv1=(ImageView) findViewById(R.id.iv1);
  
 // 权限申请
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED)
        {
            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},MY_PERMISSIONS_REQUEST_CALL_PHONE);
        } else
        {
        }
    }
 
 // 权限回调
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)
    {
 
        if (requestCode == MY_PERMISSIONS_REQUEST_CALL_PHONE)
        {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
            } else
            {
                // Permission Denied
                Toast.makeText(MainActivity.this, "Permission Denied", Toast.LENGTH_SHORT).show();
            }
            return;
        }
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
	
	 // 避免图片太大挂了
    // 默认情况下 每个 anroid 给应用分配最大 堆大小16M (VM heap)
    public void sendNotification(View view) {
 
 
        // 设置为true,那么不解析图片，获取图片部分信息
        BitmapFactory.Options opts=new BitmapFactory.Options();
        // 如果这里设置为true,那么就不为图片分配内存，而是起到对图片测量的公共
        // 查看bitmap信息，获取图片的头部信息
        opts.inJustDecodeBounds=true;
        BitmapFactory.decodeFile("/sdcard/1.jpg",opts);
        int imageHeight=opts.outHeight;
        int imageWidth=opts.outWidth;
        Log.e("Tag", "图片的高:"+imageHeight);
        Log.e("Tag", "图片的宽:"+imageWidth);
        // 得到手机屏幕的宽高
        int scaleX=imageWidth/WindowWidth;
        int scaleY=imageHeight/WindowHeight;
        int scale=1;
        // 按照大的来缩放,避免显示到屏幕外面
        if(scaleX>scaleY && scaleY>=1){
            scale=scaleX;
        }
        if(scaleY>scaleX && scaleX>=1){
            scale=scaleY;
        }
        // 解析图片
        opts.inJustDecodeBounds=false;
        // 采样率
        opts.inSampleSize=scale;
        Bitmap bitmap=BitmapFactory.decodeFile("/sdcard/1.jpg",opts);
        iv1.setImageBitmap(bitmap);
    }
 
 
}

图片头信息读取Api:

通过api:ExifInterface
     比如拍摄时间
    ExifInterface exif= null;
    try {
        exif = new ExifInterface("/sdcard/1.jpg");
    } catch (IOException e) {
        Log.e("Tag", "图片异常");
        e.printStackTrace();
    }
    String time=exif.getAttribute(ExifInterface.TAG_DATETIME); //通过getAttribute()获取照片的属性：时间、
    Log.e("Tag", "拍摄时间:"+time);
    String type=exif.getAttribute(ExifInterface.TAG_MODEL);
    String location = exif.getAttribute(ExifInterface.TAG_GPS_LONGITUDE);
    Log.e("Tag", "相机是:"+type);
    Log.e("Tag", "拍摄地点:"+location);