Picasso.with(context)
    .load(img_url)
    .config(Bitmap.Config.RGB_565)
    .into(imageView);

Picasso.with(context)
    .load(img_url)
    .config(Bitmap.Config.RGB_565)
    .memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE)
    .into(imageView);

Picasso.with(context)
    .load(img_url)
    .config(Bitmap.Config.RGB_565)
    .memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE)
    .transform(new BlurTransformation(this))
    .into(imageView);

public class BlurTransformation implements Transformation {
  RenderScript rs;
 
  public BlurTransformation(Context context) {
    super();
    rs = RenderScript.create(context);
  }
 
  @Override
  public Bitmap transform(Bitmap bitmap) {
    Bitmap blurredBitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);
 
    Allocation input = Allocation.createFromBitmap(rs, blurredBitmap, Allocation.MipmapControl.MIPMAP_FULL, Allocation.USAGE_SHARED);
    Allocation output = Allocation.createTyped(rs, input.getType());
 
    ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
    script.setInput(input);
 
    //设置模糊半径
    script.setRadius(14);
 
    script.forEach(output);
 
    output.copyTo(blurredBitmap);
 
    bitmap.recycle();
 
    return blurredBitmap;
  }
 
  @Override
  public String key() {
    return "blur";
  }
}