It's well known that JPEG image compression can result in quantization artifacts and blocking artifacts. There are plenty of forensic techniques making use of image's compression fingerprints to verify digital images. However, when a forger exists, these methods are not reliable any more. One typical anti-forensic method is adding anti-forensic dither to DCT transform coefficients and erasing blocking artifacts to remove compression history. In this paper, we propose a new countering anti-forensic method based on estimating the noise added in the process of erasing blocking artifacts. The experimental results show that our method obtains an average detection accuracy of 98% on the UCID image database. Another advantage of our proposed method is that it has only one-dimensional feature and time-saving. Furthermore, we use the game theory to evaluate the performance of both sides, and identify the optimal strategies of both sides.