【Android】Android缩放图片大小，保存图片

public static Bitmap rotateBitmap(Bitmap bmp, float degree) {        Matrix matrix = new Matrix();        matrix.postRotate(degree);  //旋转        matrix.postScale(-1, 1);  //镜像水平翻转        return Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(), bmp.getHeight(), matrix, true);    }

Button button_snap = (Button)findViewById(R.id.buttonsnap);        button_snap.setOnClickListener(new View.OnClickListener(){            public void onClick(View v){                Camera.Size size = mCamera.getParameters().getPreviewSize();                final int w = size.width;                final int h = size.height;                final YuvImage image = new YuvImage(mDataSingle, ImageFormat.NV21, w, h, null);                ByteArrayOutputStream os = new ByteArrayOutputStream(mDataSingle.length);                if( !image.compressToJpeg(new Rect(0,0,w,h), 100, os)){                    return;                }                byte[] tmp = os.toByteArray();                Bitmap bitmap = BitmapFactory.decodeByteArray(tmp, 0, tmp.length);                Bitmap input = rotateBitmap(bitmap, -90);                Bitmap bmp = input.copy(Bitmap.Config.ARGB_8888, true);                saveBitmap(bmp, "size0.jpg");                                int nw = bmp.getWidth();                int nh = bmp.getHeight();                int[] pix = new int[nw * nh];                bmp.getPixels(pix, 0, nw, 0, 0, nw, nh);                int[] resultPixels = mFaceRecognizer.bitmapFace(pix, nw, nh); //返回结果                Bitmap result = Bitmap.createBitmap(nw, nh, Bitmap.Config.ARGB_8888);                result.setPixels(resultPixels,0,nw,0,0,nw,nh);                imageSnapFace.setImageBitmap(result);                saveBitmap(result, "result.jpg");            }        });

public static Bitmap getScaledBitmap(Bitmap m_img, float sx, float sy) {        Matrix matrix = new Matrix();        matrix.postScale(sx, sy);        Bitmap rst = Bitmap.createBitmap(m_img, 0, 0, m_img.getWidth(), m_img.getHeight(), matrix, true);        return rst;    }

img = getScaledBitmap(imgTemp, 0.1f, 0.1f);   //缩小图片imageView.setImageBitmap(img);

//保存图片    public static void saveBitmap(Bitmap bm, String picName) {        File f = new File("/storage/emulated/0/Pictures/", picName);        if (f.exists()) {            f.delete();        }        try {            FileOutputStream out = new FileOutputStream(f);            bm.compress(Bitmap.CompressFormat.PNG, 90, out);            out.flush();            out.close();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

saveBitmap(img, "MyScaleImg.png");  //保存图片

完整版：

//缩放图片大小    public static Bitmap getScaledBitmap(Bitmap m_img, float sx, float sy) {        Matrix matrix = new Matrix();        matrix.postScale(sx, sy);        Bitmap rst = Bitmap.createBitmap(m_img, 0, 0, m_img.getWidth(), m_img.getHeight(), matrix, true);        return rst;    }    //保存图片    public static void saveBitmap(Bitmap bm, String picName) {        File f = new File("/storage/emulated/0/Pictures/", picName);        if (f.exists()) {            f.delete();        }        try {            FileOutputStream out = new FileOutputStream(f);            bm.compress(Bitmap.CompressFormat.PNG, 90, out);            out.flush();            out.close();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    @Override    protected void onDestroy(){        super.onDestroy();        detecter.release(this);    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {        super.onActivityResult(requestCode, resultCode, intent);        if (requestCode == PICTURE_CHOOSE) {            if (intent != null) {                try {                    //加载图片并显示                    ContentResolver resolver = getContentResolver();                    Uri originalUri = intent.getData();//获得图片的uri                    Bitmap imgTemp = MediaStore.Images.Media.getBitmap(resolver, originalUri);                    img = getScaledBitmap(imgTemp, 0.3f, 0.3f);   //-----------缩小图片                    imageView.setImageBitmap(img);                    //获取图片的路径                    Cursor cursor = getContentResolver().query(intent.getData(), null, null, null, null);                    cursor.moveToFirst();                    int idx = cursor.getColumnIndex(ImageColumns.DATA);                    String fileSrc = cursor.getString(idx);                    textViewDebug.setText("Picture:" + fileSrc);                    textView.setText("图片加载成功！");                    buttonDetect.setVisibility(View.VISIBLE);                    saveBitmap(img, "MyScaleImg.png");  //---------------------保存图片                    }catch (IOException e) {                    textView.setText("TAG-->Error" + e.toString());                    }            }            else {                textViewDebug.setText("intent == null");            }        }    }//onActivityResult()

//保存图片    public static void saveBitmap(Bitmap bm, String picName) {        File f = new File("/storage/emulated/0/Pictures/", picName);        if (f.exists()) {            f.delete();        }        try {            FileOutputStream out = new FileOutputStream(f);            bm.compress(Bitmap.CompressFormat.PNG, 90, out);            out.flush();            out.close();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    //length用户要求产生字符串的长度    public static String getRandomString(int length){        String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        Random random=new Random();        StringBuffer sb=new StringBuffer();        for(int i=0;i<length;i++){            int number=random.nextInt(62);            sb.append(str.charAt(number));        }        return sb.toString();    }