壓縮100k圖片不失真的方法；先獲取圖片的原始長度和寬度；然後計算圖片的縮放值；最後等比例壓縮；

下面程式碼是壓縮的工具類；

public class PictureUtil {


	/**
	 * 主方法
	 * 
	 * @param filePath
	 * @return
	 */
	public static InputStream bitmapToString(String filePath) {

		Bitmap bm = getSmallBitmap(filePath);

		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		bm.compress(Bitmap.CompressFormat.JPEG, 60, baos);
		// 把壓縮後的資料baos存放到ByteArrayInputStream中
		ByteArrayInputStream isBm = new ByteArrayInputStream(
				baos.toByteArray());
		return isBm;
	}

	/**
	 * 計算圖片的縮放值
	 * 
	 * @param options
	 * @param reqWidth
	 * @param reqHeight
	 * @return
	 */
	public static int calculateInSampleSize(BitmapFactory.Options options,
			int reqWidth, int reqHeight) {
		// Raw height and width of image
		final int height = options.outHeight;
		final int width = options.outWidth;
		int inSampleSize = 1;

		if (height > reqHeight || width > reqWidth) {

			// Calculate ratios of height and width to requested height and
			// width
			final int heightRatio = Math.round((float) height
					/ (float) reqHeight);
			final int widthRatio = Math.round((float) width / (float) reqWidth);

			// Choose the smallest ratio as inSampleSize value, this will
			// guarantee
			// a final image with both dimensions larger than or equal to the
			// requested height and width.
			inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
		}

		return inSampleSize;
	}




	/**
	 * 根據路徑獲得突破並壓縮返回bitmap用於顯示
	 * 
	 * @param imagesrc
	 * @return
	 */
	public static Bitmap getSmallBitmap(String filePath) {
		final BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeFile(filePath, options);

		// Calculate inSampleSize
		options.inSampleSize = calculateInSampleSize(options, 800, 480);

		// Decode bitmap with inSampleSize set
		options.inJustDecodeBounds = false;

		return BitmapFactory.decodeFile(filePath, options);
	}

	/**
	 * 根據路徑刪除圖片
	 * 
	 * @param path
	 */
	public static void deleteTempFile(String path) {
		File file = new File(path);
		if (file.exists()) {
			file.delete();
		}
	}

	/**
	 * 新增到相簿
	 */
	public static void galleryAddPic(Context context, String path) {
		Intent mediaScanIntent = new Intent(
				Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
		File f = new File(path);
		Uri contentUri = Uri.fromFile(f);
		mediaScanIntent.setData(contentUri);
		context.sendBroadcast(mediaScanIntent);
	}

	/**
	 * 獲取儲存圖片的目錄
	 * 
	 * @return
	 */
	public static File getAlbumDir() {
		File dir = new File(
				Environment
				.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
				getAlbumName());
		if (!dir.exists()) {
			dir.mkdirs();
		}
		return dir;
	}

	/**
	 * 獲取儲存 隱患檢查的圖片資料夾名稱
	 * 
	 * @return
	 */
	public static String getAlbumName() {
		return "sheguantong";
	}
}
 

**
 * 
 * 上傳工具類上傳壓縮；
 * @author spring sky
 * Email:[email protected]
 * QQ:840950105
 * MyName:石明政
 */
public class UploadUtil {
	private static final String TAG = "uploadFile";
	private static final int TIME_OUT = 10*1000;   //超時時間
	private static final String CHARSET = "utf-8"; //設定編碼
	/**
	 * android上傳檔案到伺服器
	 * @param file  需要上傳的檔案
	 * @param RequestURL  請求的rul
	 * @return  返回響應的內容
	 */
	public static String uploadFile(String file,String RequestURL)
	{
		String result = null;
		String  BOUNDARY =  UUID.randomUUID().toString();  //邊界標識   隨機生成
		String PREFIX = "--" , LINE_END = "\r\n"; 
		String CONTENT_TYPE = "multipart/form-data";   //內容型別

		try {
			URL url = new URL(RequestURL);
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			conn.setReadTimeout(TIME_OUT);
			conn.setConnectTimeout(TIME_OUT);
			conn.setDoInput(true);  //允許輸入流
			conn.setDoOutput(true); //允許輸出流
			conn.setUseCaches(false);  //不允許使用快取
			conn.setRequestMethod("POST");  //請求方式
			conn.setRequestProperty("Charset", CHARSET);  //設定編碼
			conn.setRequestProperty("connection", "keep-alive");   
			conn.setRequestProperty("Content-Type", CONTENT_TYPE + ";boundary=" + BOUNDARY); 

			if(file!=null){
				/**
				 * 當檔案不為空，把檔案包裝並且上傳
				 */
				DataOutputStream dos = new DataOutputStream(conn.getOutputStream());
				InputStream is =PictureUtil.bitmapToString(file);
				byte[] bytes = new byte[9000];
				int len = 0;
				while((len=is.read(bytes))!=-1){
					dos.write(bytes, 0, len);
				}
				is.close();
				dos.write(LINE_END.getBytes());
				byte[] end_data = (PREFIX+BOUNDARY+PREFIX+LINE_END).getBytes();
				dos.write(end_data);
				dos.flush();
				/**
				 * 獲取響應碼  200=成功
				 * 當響應成功，獲取響應的流  
				 */
				int res = conn.getResponseCode();  
				Log.e(TAG, "response code:"+res);
				//                if(res==200)
				//                {
				Log.e(TAG, "request success");
				InputStream input =  conn.getInputStream();
				StringBuffer sb1= new StringBuffer();
				int ss ;
				while((ss=input.read())!=-1)
				{
					sb1.append((char)ss);
				}
				result = sb1.toString();
				Log.e(TAG, "result : "+ result);
				//                }
				//                else{
				//                    Log.e(TAG, "request error");
				//                }
			}
		} catch (MalformedURLException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return result;
	}



	public static InputStream compressImage(String file) {
		Bitmap bitmap = BitmapFactory.decodeFile(file);
		BitmapFactory.Options newOpts = new BitmapFactory.Options();
		// 開始讀入圖片，此時把options.inJustDecodeBounds設為true
		newOpts.inJustDecodeBounds = true;
		bitmap = BitmapFactory.decodeFile(file, newOpts);
		newOpts.inJustDecodeBounds = false;
		int w = newOpts.outWidth;
		int h = newOpts.outHeight;
		// 設定解析度
		float hh = 800f;
		float ww = 400f;
		// 縮放比。由於是固定的比例縮放，只用高或者寬其中一個數據進行計算即可
		int be = 1;
		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) {// 如果寬度大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;// 設定縮放比例
		// 重新讀入圖片，注意此時已經把newOpts.inJustDecodeBounds = false
		bitmap = BitmapFactory.decodeFile(file, newOpts);
		try {
			//			Bitmap bitmapyas=compressImage1(bitmap);
			return compressImage2(bitmap);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
	}

	public static InputStream compressImage2(Bitmap bitmap) throws Exception {
		try {
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
			int options = 100;
			int size = baos.toByteArray().length / 1024;
			while (size > 40 && options > 0) {
				baos.reset();// 重置baos即清空baos
				options -=10;// 每次都減少10
				// 這裡壓縮options%，把壓縮後的資料存放到baos中
				bitmap.compress(Bitmap.CompressFormat.JPEG, options, baos);
				size = baos.toByteArray().length / 1024;
			}
			// 把壓縮後的資料baos存放到ByteArrayInputStream中
			ByteArrayInputStream isBm = new ByteArrayInputStream(
					baos.toByteArray());
			return isBm;

		} catch (Exception e) {
			throw e;
		}
	}
}