Android应用中实现图片压缩的方法有哪些

public class Utils { 
 
  /** 
   * 采样率压缩 
   * 
   * @param bitmap 
   * @param sampleSize 采样率为2的整数倍，非整数倍四舍五入，如4的话，就是原图的1/4 
   * @return 尺寸变化 
   */ 
  public static Bitmap getBitmap(Bitmap bitmap, int sampleSize) { 
    BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inSampleSize = sampleSize; 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos); 
    byte[] bytes = baos.toByteArray(); 
    Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length, options); 
    Log.i("info", "图片大小：" + bit.getByteCount());//2665296  10661184 
    return bit; 
  } 
 
  /** 
   * 图片质量压缩 
   * 
   * @param bitmap 
   * @param quality 
   * @return 尺寸不变，质量变小 
   */ 
  public static Bitmap compressByQuality(Bitmap bitmap, int quality) { 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    bitmap.compress(Bitmap.CompressFormat.JPEG, quality, baos); 
    byte[] bytes = baos.toByteArray(); 
    Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); 
    Log.i("info", "图片大小：" + bit.getByteCount());//10661184 
    return bit; 
  } 
 
  /** 
   * 图片质量压缩 
   * 
   * @param src 
   * @param maxByteSize 
   * @return 
   */ 
  public static Bitmap compressByQuality(Bitmap src, long maxByteSize) { 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    int quality = 100; 
    src.compress(Bitmap.CompressFormat.JPEG, quality, baos); 
    while (baos.toByteArray().length > maxByteSize && quality > 0) { 
      baos.reset(); 
      src.compress(Bitmap.CompressFormat.JPEG, quality -= 5, baos); 
    } 
    if (quality < 0) return null; 
    byte[] bytes = baos.toByteArray(); 
    Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); 
    return bit; 
  } 
 
  public static Bitmap compressByFormat(Bitmap bitmap, int format) { 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos); 
    byte[] bytes = baos.toByteArray(); 
    Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); 
    Log.i("info", "图片大小：" + bit.getByteCount());//10661184 
    return bit; 
  } 
 
  /** 
   * Matrix缩放 
   * 
   * @param bitmap 
   * @param scaleWidth 
   * @param scaleHeight 
   * @return 尺寸和大小变化 
   */ 
  public static Bitmap getBitmapBySize(Bitmap bitmap, float scaleWidth, float scaleHeight) { 
    Matrix matrix = new Matrix(); 
    matrix.postScale(scaleWidth, scaleHeight); 
    Bitmap bit = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, false); 
    Log.i("info", "图片大小：" + bit.getByteCount()); 
    return bit; 
  } 
 
  /** 
   * 按照图片格式配置压缩 
   * 
   * @param path 
   * @param config ALPHA_8,ARGB_4444,ARGB_8888,RGB_565; 
   * @return RGB_565比ARGB_8888节省一半内存 
   */ 
  public static Bitmap getBitmapByFormatConfig(String path, Bitmap.Config config) { 
    BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inPreferredConfig = config; 
    Bitmap bitmap = BitmapFactory.decodeFile(path, options); 
    Log.i("info", "图片大小：" + bitmap.getByteCount()); 
    return bitmap; 
  } 
 
  /** 
   * 指定大小缩放 
   * 
   * @param bitmap 
   * @param width 
   * @param height 
   * @return 
   */ 
  public static Bitmap getBitmapByScaleSize(Bitmap bitmap, int width, int height) { 
    Bitmap bit = Bitmap.createScaledBitmap(bitmap, width, height, true); 
    Log.i("info", "图片大小：" + bit.getByteCount()); 
    return bit; 
  } 
 
  /** 
   * 通过保存格式压缩 
   * 
   * @param bitmap 
   * @param format JPEG,PNG,WEBP 
   * @return 
   */ 
  public static Bitmap getBitmapByFormat(Bitmap bitmap, Bitmap.CompressFormat format) { 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    bitmap.compress(format, 100, baos); 
    byte[] bytes = baos.toByteArray(); 
    Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); 
    Log.i("info", "图片大小：" + bit.getByteCount()); 
    return bit; 
  } 
 
  /** 
   * 文件加载压缩 
   * 
   * @param filePath 
   * @param inSampleSize 
   * @return 
   */ 
  public static Bitmap getBitmap(String filePath, int inSampleSize) { 
    BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inJustDecodeBounds = true; 
    BitmapFactory.decodeFile(filePath, options);//此时不耗费和占用内存 
    options.inSampleSize = inSampleSize; 
    options.inJustDecodeBounds = false; 
    return BitmapFactory.decodeFile(filePath, options); 
  } 
 
  public static Bitmap getBitmap(String filePath) { 
    return BitmapFactory.decodeFile(filePath); 
  } 
 
  public static Bitmap view2Bitmap(View view) { 
    if (view == null) return null; 
    Bitmap ret = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888); 
    Canvas canvas = new Canvas(ret); 
    Drawable bgDrawable = view.getBackground(); 
    if (bgDrawable != null) { 
      bgDrawable.draw(canvas); 
    } else { 
      canvas.drawColor(Color.WHITE); 
    } 
    view.draw(canvas); 
    return ret; 
  } 
 
  public static void saveBitmap(Bitmap bitmap) { 
    File file = new File(Environment.getExternalStorageDirectory() + "/img.jpg"); 
    try { 
      FileOutputStream fileOutputStream = new FileOutputStream(file); 
      bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream); 
      fileOutputStream.flush(); 
      fileOutputStream.close(); 
    } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
  } 
 
  public static void saveBitmap(Bitmap bitmap,Bitmap.CompressFormat format) { 
    File file = new File(Environment.getExternalStorageDirectory() + "/img.jpg"); 
    try { 
      FileOutputStream fileOutputStream = new FileOutputStream(file); 
      bitmap.compress(format, 100, fileOutputStream); 
      fileOutputStream.flush(); 
      fileOutputStream.close(); 
    } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
  } 
}