Recognizing handwritten digits is a challenging task primarily due to the
diversity of writing styles and the presence of noisy images. The widely used
MNIST dataset, which is commonly employed as a benchmark for this task,
includes distorted digits with irregular shapes, incomplete strokes, and
varying skew in both the training and testing datasets. Consequently, these
factors contribute to reduced accuracy in digit recognition. To overcome this
challenge, we propose a two-stage deep learning approach. In the first stage,
we create a simple neural network to identify distorted digits within the
training set. This model serves to detect and filter out such distorted and
ambiguous images. In the second stage, we exclude these identified images from
the training dataset and proceed to retrain the model using the filtered
dataset. This process aims to improve the classification accuracy and
confidence levels while mitigating issues of underfitting and overfitting. Our
experimental results demonstrate the effectiveness of the proposed approach,
achieving an accuracy rate of over 99.5% on the testing dataset. This
significant improvement showcases the potential of our method in enhancing
digit classification accuracy. In our future work, we intend to explore the
scalability of this approach and investigate techniques to further enhance
accuracy by reducing the size of the training data.

我们提出了一种两阶段深度学习方法，用于识别手写数字，通过过滤失真和模糊图像来改善分类准确度，并在测试数据集上达到 99.5% 的准确率。