對於獲取到的圖片進行壓縮然後上傳，這個事情還是很重要的而且是很實用的。

public byte[] compressBitmap(Bitmap bitmap) {
    ByteArrayOutputStream baos = null;
    try {
        baos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        baos.close();
        BitmapFactory.Options options = new 
 
BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        byte[] buffer = baos.toByteArray();
        BitmapFactory.decodeByteArray(buffer, 0, buffer.length, options);
        int outWidth = options.outWidth;
        int scale = outWidth / WIDTH;
        if (scale > 1) {
            options.inSampleSize 
 
= scale;
            options.inJustDecodeBounds = false;
            Bitmap tempBitmap = BitmapFactory.decodeByteArray(buffer, 0, buffer.length, options);
            baos = new ByteArrayOutputStream();
            tempBitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
            baos.close();
        }
        return 
 
baos.toByteArray();
    } catch (Exception e) {
        return null;
    } finally {
        try {
            if (baos != null) {
                baos.close();
            }
        } catch (IOException e) {
            return null;
        }
    }
}

public byte[] compressBitmap(byte[] buffer) {
    if (buffer == null || buffer.length == 0) {
        return null;
    }
    ByteArrayOutputStream baos = null;
    try {
        // 只獲取圖片的大小資訊，而不是將整張圖片載入在記憶體中，避免記憶體溢位
BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeByteArray(buffer, 0, buffer.length, options);
        int outWidth = options.outWidth;
        int scale = outWidth / WIDTH;
        if (scale > 1) {
            options.inSampleSize = scale;
            options.inJustDecodeBounds = false;
            Bitmap bitmap = BitmapFactory.decodeByteArray(buffer, 0, buffer.length, options);
            baos = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
            return baos.toByteArray();
        } else {
            return buffer;
        }
    } catch (Exception e) {
        return null;
    } catch (OutOfMemoryError e) {
        return null;
    } finally {
        try {
            if (baos != null) {
                baos.close();
            }
        } catch (IOException e) {
            return null;
        }
    }
}


public Bitmap compressBitmap(String path) {
    Bitmap bitmap = null;
    try {
        bitmap = BitmapFactory.decodeFile(path);
        int scale = 1;
        if(bitmap.getWidth() > bitmap.getHeight()){
            //橫向拍攝的照片
scale = bitmap.getHeight() / WIDTH;
        }else{
            //豎屏拍攝的照片
scale = bitmap.getWidth() / WIDTH;
        }
        BitmapFactory.Options opt = new BitmapFactory.Options();
        opt.inJustDecodeBounds = false;
        if (scale > 1) {
            //壓縮到1/scale
opt.inSampleSize = scale;
            bitmap = BitmapFactory.decodeFile(path, opt);
        } else {
            bitmap = BitmapFactory.decodeFile(path, opt);
        }
    } catch (OutOfMemoryError e) {
        return null;
    }
    return bitmap;
}

public byte[] bitmapToByte(Bitmap bitmap) {
    ByteArrayOutputStream bos = null;
    try {
        if (bitmap == null) {
            return null;
        }
        bos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos);
        return bos.toByteArray();

    } catch (Exception e) {
        return null;
    } catch (OutOfMemoryError e) {
        return null;
    } finally {
        try {
            if (bos != null)
                bos.close();
        } catch (IOException e) {
            return null;
        }
    }
}