// v3以前
Glide.with(context)
  .loadFromMediaStore(localMedia.getLocalPath())
  .asBitmap()
  .imageDecoder(new StreamBitmapDecoder(
    Downsampler.AT_LEAST,
    Glide.get(mContext).getBitmapPool(),
    DecodeFormat.PREFER_ARGB_8888
    ))
  .into(imageView);

// v4以降
// optionオブジェクトを構築して…
RequestOptions options = new RequestOptions()
                .format(DecodeFormat.PREFER_ARGB_8888)
                .downsample(DownsampleStrategy.AT_LEAST);
// applyでoptionsをset
GlideApp.with(context)
  .asBitmap()
  .load(uri)
  .apply(options)
  .into(imageView);