在 android 中，如何以编程方式将图像大小从 70 kb 减小到 30 kb？

Question

我正在 android 中开发一个应用程序，它将捕获照片并存储在 sqlite 中。 图像大小为 70 kb，但我想以 35 kb 大小存储该图像。但我对此一无所知。我尝试了以下代码，但没有成功。

int photo_width = bm.getWidth();
int photo_height = bm.getHeight();

photo_width = 260;
photo_height = 260;

Bitmap photobitmap = Bitmap.createScaledBitmap(bm,
    photo_width, photo_height, false);

Answer 1

使用这个：

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    Matrix matrix = new Matrix();
    matrix.postScale(scaleWidth, scaleHeight);
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height,
            matrix, false);

    return resizedBitmap;
}

你可以用这个……这是最好的例子……

  private Bitmap decodeFile(File f){
   try {
    //Decode image size
    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(new FileInputStream(f),null,o);

    //The new size we want to scale to
    final int REQUIRED_SIZE=70;

    //Find the correct scale value. It should be the power of 2.
    int scale=1;
    while(o.outWidth/scale/2>=REQUIRED_SIZE && o.outHeight/scale/2>=REQUIRED_SIZE)
        scale*=2;

    //Decode with inSampleSize
    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize=scale;
    return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
  } catch (FileNotFoundException e) {}
  return null;
  }

Answer 2

您可以使用Bitmap.compress() 生成压缩版本。