我的图片在android中为黑色

Question

朋友，我现在正在使用图像隐写术。为此，我需要将图像转换为位数组并将其解码。但是，当我尝试将图像转换回其原始形状时，它在我的ImageView中只显示黑色。这里是我的代码

btnEncode =（按钮）findViewById（R.id.encode）; btnEncode.setOnClickListener（新View.OnClickListener（）{

 @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 

      //imgPath.setText(imageToBase64(selectedImagePath)); 
      ImageView imageView=(ImageView)findViewById(R.id.imageView1); 
      BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable(); 
      Bitmap bitmap = drawable.getBitmap(); 

       bytes = getBytesFromBitmap(bitmap); 
       StringBuilder binary = new StringBuilder(); 
       for (byte b : bytes) 
       { 
       int val = b; 
       for (int i = 0; i < 8; i++) 
       { 
        binary.append((val & 128) == 0 ? 0 : 1); 
        val <<= 1; 
       } 
       binary.append(' '); 
       } 

       //To save the binary in newString 

      String ImageEncoded=new String(binary.toString()); 
      TextView imgData=(TextView)findViewById(R.id.txtResult); 
      imgData.setText(ImageEncoded); 
     } 
    }); 
    btnDecode = (Button) findViewById(R.id.decode); 
    btnDecode.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) 
     { 
      // TODO Auto-generated method stub 
      ImageView imageView=(ImageView)findViewById(R.id.imageView1); 
      BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable(); 
      Bitmap bitmap = drawable.getBitmap(); 

       bytes = getBytesFromBitmap(bitmap); 

      Bitmap bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); 
      ImageView image = (ImageView) findViewById(R.id.imageView2); 

      image.setImageBitmap(bmp); 
     } 
    }); 

public static byte[] getBytesFromBitmap(Bitmap bitmap) 
{ 
    ByteArrayOutputStream stream = new ByteArrayOutputStream(); 
    bitmap.compress(CompressFormat.JPEG, 70, stream); 
    return stream.toByteArray(); 
} 

Answer 1

其对您的转换格式，使用CompressFormat.PNG，而不是CompressFormat.JPEG，这引发的 “JPEG文件不做透明度像PNG”。