多媒體圖片壓縮工具類

public class MediaUtils {

    private MediaUtils() {
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * @param bMute 值爲true時爲關閉背景音樂。
     */
    @TargetApi(Build.VERSION_CODES.FROYO) public static boolean muteAudioFocus(Context context,
        boolean bMute) {
        boolean bool = false;
        AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
        if (bMute) {
            int result =
                am.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
            bool = result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED;
        } else {
            int result = am.abandonAudioFocus(null);
            bool = result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED;
        }
        return bool;
    }

    /*
     * 3.質量壓縮
     * 設置bitmap options屬性，降低圖片的質量，像素不會減少
     * 第一個參數爲需要壓縮的bitmap圖片對象，第二個參數爲壓縮後圖片保存的位置
     * 設置options 屬性0-100，來實現壓縮
     *
     * @param bmp
     * @param file
     */
    public static void qualityCompress(String imgPath, String outImg) {
        File file = new File(outImg);
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(imgPath);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        Bitmap bitmap = BitmapFactory.decodeStream(fis);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int options = 20;
        bitmap.compress(Bitmap.CompressFormat.JPEG, options, baos);
        while (baos.toByteArray().length / 1024 > 190 && options > 5) { // 循環判斷如果壓縮後圖片是否大於100kb,大於繼續壓縮

            baos.reset(); // 重置baos即清空baos
            bitmap.compress(Bitmap.CompressFormat.JPEG, options, baos);// 這裏壓縮options%，把壓縮後的數據存放到baos中
            options -= 5;// 每次都減少5
        }
        try {
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(baos.toByteArray());
            fos.flush();
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 質量壓縮方法
     */
    public static void compressImage(Bitmap image, String outImg) {
        File file = new File(outImg);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, baos);// 質量壓縮方法，這裏100表示不壓縮，把壓縮後的數據存放到baos中
        /*int options = 90;

        while (baos.toByteArray().length / 1024 > 200 && options >= 10) { // 循環判斷如果壓縮後圖片是否大於100kb,大於繼續壓縮
            baos.reset(); // 重置baos即清空baos
            image.compress(Bitmap.CompressFormat.JPEG, options, baos);// 這裏壓縮options%，把壓縮後的數據存放到baos中
            options -= 10;// 每次都減少10
            LogUtil.e("圖片壓縮中", "");
            LogUtil.e("options:", "" + options);
        }*/

        try {
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(baos.toByteArray());
            fos.flush();
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Compress image by size, this will modify image width/height.
     * Used to get thumbnail
     *
     * @param pixelW target pixel of width
     * @param pixelH target pixel of height
     */
    public static void ratio(String imgPath, String outImg, float pixelW, float pixelH) {
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(imgPath);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        Bitmap image = BitmapFactory.decodeStream(fis);
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, os);
        //判斷如果圖片大於1M,進行壓縮避免在生成圖片（BitmapFactory.decodeStream）時溢出
        if (os.toByteArray().length / 1024 > 180) {
            os.reset();//重置baos即清空baos
            image.compress(Bitmap.CompressFormat.JPEG, 90, os);//這裏壓縮50%，把壓縮後的數據存放到baos中
        }
        ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        //開始讀入圖片，此時把options.inJustDecodeBounds 設回true了
        newOpts.inJustDecodeBounds = true;
        newOpts.inPreferredConfig = Bitmap.Config.RGB_565;
        Bitmap bitmap = BitmapFactory.decodeStream(is, null, newOpts);
        newOpts.inJustDecodeBounds = false;
        int w = newOpts.outWidth;
        int h = newOpts.outHeight;
        float hh = pixelH;// 設置高度爲240f時，可以明顯看到圖片縮小了
        float ww = pixelW;// 設置寬度爲120f，可以明顯看到圖片縮小了
        //縮放比。由於是固定比例縮放，只用高或者寬其中一個數據進行計算即可
        int be = 1;//be=1表示不縮放
        if (w > h && w > ww) {//如果寬度大的話根據寬度固定大小縮放
            be = (int) (newOpts.outWidth / ww);
        } else if (w < h && h > hh) {//如果高度高的話根據寬度固定大小縮放
            be = (int) (newOpts.outHeight / hh);
        }
        if (be <= 0) be = 1;
        newOpts.inSampleSize = be;//設置縮放比例
        //重新讀入圖片，注意此時已經把options.inJustDecodeBounds 設回false了
        is = new ByteArrayInputStream(os.toByteArray());
        bitmap = BitmapFactory.decodeStream(is, null, newOpts);
        //壓縮好比例大小後再進行質量壓縮
        compressImage(bitmap, outImg);
    }
}