调整大小时Android的质量不佳位图

Question

当我在应用程序中调整一个图像位图的大小时，出现问题，图像质量下降。

我调整大小的代码如下..

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) { 
    Bitmap scaledBitmap = Bitmap.createBitmap(newWidth, newHeight, 
      Config.ARGB_8888); 

    float ratioX = newWidth/(float) bm.getWidth(); 
    float ratioY = newHeight/(float) bm.getHeight(); 
    float middleX = newWidth/2.0f; 
    float middleY = newHeight/2.0f; 

    Matrix scaleMatrix = new Matrix(); 
    scaleMatrix.postScale(ratioX, ratioY, middleX, middleY); 

    Paint paint = new Paint(); 
    paint.setAntiAlias(true); 
    paint.setFilterBitmap(true); 
    paint.setDither(true); 

    Canvas canvas = new Canvas(scaledBitmap); 
    canvas.setMatrix(scaleMatrix); 
    canvas.drawBitmap(bm, middleX - bm.getWidth()/2, 
      middleY - bm.getHeight()/2, paint); 
    return scaledBitmap; 
} 

调整大小的位图¿什么好的解决办法？

Answer 1

使用此代码，我希望它会帮助你

/*** 
* This method is for aspect ratio means the image is set acc. to the aspect 
* ratio. 
* 
* @param bmp 
*   bitmap passed 
* @param newWidth 
*   width you want to set for your image 
* @param newHeight 
*   hight you want to set for your image 
* @return bitmap 
*/ 
public Bitmap resizeBitmap(Bitmap bmp, int newWidth, int newHeight) { 
    Log.i(TAG, 
      "height = " + bmp.getHeight() + "\nwidth = " + bmp.getWidth()); 
    if (bmp.getHeight() > newHeight || bmp.getWidth() > newWidth) { 
     int originalWidth = bmp.getWidth(); 
     int originalHeight = bmp.getHeight(); 
     Log.i("TAG", "originalWidth = " + originalWidth 
       + "\noriginalHeight = " + originalHeight); 
     float inSampleSize; 
     if (originalWidth > originalHeight) { 
      inSampleSize = (float) newWidth/originalWidth; 
     } else { 
      inSampleSize = (float) newHeight/originalHeight; 
     } 
     newWidth = Math.round(originalWidth * inSampleSize); 
     newHeight = Math.round(originalHeight * inSampleSize); 
     Log.i("", "newWidth = " + newWidth + "\nnewHeight = " + newHeight); 
     bitmap = Bitmap.createScaledBitmap(bmp, newWidth, newHeight, true); 
    } else { 
     bitmap = bmp; 
     Log.i("", "bitmapWidth = " + bitmap.getWidth() 
       + "\nbitmapHeight = " + bitmap.getHeight()); 
    } 
    return bitmap; 
}