bitmap处理BitmapFactory.Options.inSampleSize

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">今天也是项目需要上传拍照，现在手机拍一张多有一两M了，我们限制的是100k就开始了图片缩小处理，</span>

我的方案是先压缩分辨率， 在压缩质量。我的300w像素照片也有2048*1536了，上传的照片分辨率没必要那么大切涨内存

借鉴网上方法

public static byte[] comp(String path) {  ByteArrayOutputStream baos = new ByteArrayOutputStream();  BitmapFactory.Options newOpts = new BitmapFactory.Options();   newOpts.inJustDecodeBounds = true;  Bitmap bitmap = BitmapFactory.decodeFile(path, newOpts);//打开空图片获取分辨率  baos.reset();  newOpts.inSampleSize = getinSampleSize(newOpts);  newOpts.inJustDecodeBounds = false;  Bitmap bitmap1 = BitmapFactory.decodeFile(path, newOpts);  boolean b = bitmap1.compress(CompressFormat.PNG, 100, baos);    System.out.println("lenght:"+(baos.toByteArray().length/1024));  return baos.toByteArray();//   }

  public static int getinSampleSize(BitmapFactory.Options options) {final int height = options.outHeight;final int width = options.outWidth;    float reqHeight=800.0f;    float reqWidth=480.0f;int inSampleSize = 1;if (height > width && height>reqHeight) {inSampleSize = (int) Math.ceil(height/ reqHeight);System.out.println(inSampleSize+"inSampleSize");}else if(height<=width && width>reqWidth){inSampleSize = (int) Math.ceil( width / reqWidth);System.out.println(inSampleSize+"inSampleSize");}System.out.println("inSampleSize" + inSampleSize);return inSampleSize;}

但是问题也出来了，

1，当newOpts.inSampleSize=3的时候，图片其实压缩了2倍，而google只说建议用2 的整数倍，没说不能用单数啊，没解决掉，

2，当拍照之后我BitmapFactory.decodeFile(path)取出图片再转成流存入，发现原本800k的照片居然有3m了，大概看到网上说的

3m的照片转成bitmap之后居然有30m，还说bitmap是用图片的分辨率高*宽在乘以颜色编码，那就说和照片本地大小没关系咯，我测试还是右关系的

不知道原因i。有时间在深究下，留下问好，让路人解答

2014年10月20日 17:00:59  为自己整理了一下 目的就是为了处理上传图片 因为100k还是比较大需要后台上传 于是乎就这样了

/** * 分辨率压缩 在质量压缩 *  * @param 路劲 * @return </br> 处理之后的路劲 * @throws IOException */public static String perUploadPic(String path) {ByteArrayOutputStream baos = new ByteArrayOutputStream();BitmapFactory.Options newOpts = new BitmapFactory.Options();newOpts.inJustDecodeBounds = true;BitmapFactory.decodeFile(path, newOpts);// 打开空图片获取分辨率newOpts.inSampleSize = getinSampleSize(newOpts);// 设置缩放倍数newOpts.inJustDecodeBounds = false;try {Bitmap bitmap1 = BitmapFactory.decodeFile(path, newOpts);bitmap1.compress(CompressFormat.JPEG, 80, baos);} catch (OutOfMemoryError e) {Log.e("OutOfMemoryError", "图片上传压缩初次分辨率失败");newOpts.inSampleSize = newOpts.inSampleSize + 2;Bitmap bitmap1 = BitmapFactory.decodeFile(path, newOpts);bitmap1.compress(CompressFormat.JPEG, 80, baos);}Log.e("压缩后分辨率：", newOpts.outWidth + "*" + newOpts.outHeight);Log.e("分辨率压缩后的大小:", (baos.toByteArray().length / 1024) + "");// ByteArrayOutputStream baos = new ByteArrayOutputStream();// baos.write(bytes);Bitmap bitmap = null;int options = 90;while (baos.toByteArray().length / 1024 > 100) { //if (bitmap == null)bitmap = BitmapFactory.decodeByteArray(baos.toByteArray(), 0,baos.toByteArray().length);elsebaos.reset();bitmap.compress(Bitmap.CompressFormat.JPEG, options, baos);//options -= 5;//Log.e("baos.toByteArray().length:", +baos.toByteArray().length + "");}Log.e("质量压缩后的大小:", (baos.toByteArray().length / 1024) + "");FileOutputStream out = null;File file = null;try {String[] name = path.split("/");//路劲大家自己写哈file = new File(getSDPath() + "/" + Constant.path.PAHN + "/"+ Constant.path.cameraper + "/" + name[name.length - 1]);if (!file.getParentFile().exists())file.getParentFile().mkdirs();if (!file.exists())file.createNewFile();out = new FileOutputStream(file);out.write(baos.toByteArray());out.flush();out.close();} catch (IOException e) {// TODO Auto-generated catch blocktry {out.close();baos.reset();baos = null;} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}Log.e("yung", "待上传图片压缩处理失败：" + path);e.printStackTrace();}return file.getAbsolutePath();}

/** * 获取图片压缩的比率 *  * @param options * @return */public static int getinSampleSize(BitmapFactory.Options options) {final int height = options.outHeight;final int width = options.outWidth;float reqHeight = 960.0f;//根据自己需要确定分辨率长或者宽最大不超过960 并且按照原来比例float reqWidth = 960.0f;int inSampleSize = 1;if (height > width && height > reqHeight) {inSampleSize = (int) Math.ceil(height / reqHeight);} else if (height <= width && width > reqWidth) {inSampleSize = (int) Math.ceil(width / reqWidth);}System.out.println("压缩前分辨率：" + width + "*" + height + "     压缩倍数："+ inSampleSize);return inSampleSize;}

public static File getSDPath() {File sdDir = null;if (sdCardAvailable()) {sdDir = Environment.getExternalStorageDirectory();// 获取跟目录}return sdDir;}

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