MNIST Database (mnist.pkl.gz)

The MNIST database of handwritten digits, available from this page, has a training set of 60,000 examples, and a test set of 10,000 examples. It is a subset of a larger set available from NIST. The digits have been size-normalized and centered in a fixed-size image. It is a good database for people who want to try learning techniques and pattern recognition methods on real-world data while spending minimal efforts on preprocessing and formatting. The original black and white (bilevel) images from NIST were size normalized to fit in a 20x20 pixel box while preserving their aspect ratio. The resulting images contain grey levels as a result of the anti-aliasing technique used by the normalization algorithm. the images were centered in a 28x28 image by computing the center of mass of the pixels, and translating the image so as to position this point at the center of the 28x28 field. With some classification methods (particuarly template-based methods, such as SVM and K-nearest neighbors),

MNIST手写数字数据库，可通过该页面获取，包含60,000个训练样本和10,000个测试样本。它是源自NIST更大数据集的一个子集。数据库中的数字经过尺寸归一化和居中处理，以固定尺寸的图像呈现。该数据库非常适合希望在实际世界数据上尝试学习技术和模式识别方法，同时尽量减少预处理和格式化工作的人员使用。NIST原始的黑白（双色调）图像经过尺寸归一化，以适应20x20像素的框内，同时保持其长宽比。归一化算法中使用的抗锯齿技术导致生成的图像包含灰度级。通过计算像素的质量中心，并将图像平移以使该点位于28x28字段中心，图像被居中在28x28的图像中。对于某些分类方法（尤其是基于模板的方法，如支持向量机SVM和K最近邻），