S S symmetry Article An Effective and Improved CNN-ELM Classifier for Handwritten Digits Recognition and Classification Saqib Ali 1, Jianqiang Li 1, Yan Pei 2,* , Muhammad Saqlain Aslam 3, Zeeshan Shaukat 1 and Muhammad Azeem 4 1 Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China;
[email protected] (S.A.);
[email protected] (J.L.);
[email protected] (Z.S.) 2 Computer Science Division, University of Aizu, Aizu-wakamatsu, Fukushima 965-8580, Japan 3 Department of Computer Science and Information Engineering, National Central University, Taoyuan 32001, Taiwan;
[email protected] 4 Department of Information Technology, University of Sialkot, Punjab 51040, Pakistan;
[email protected] * Correspondence:
[email protected] Received: 21 September 2020; Accepted: 17 October 2020; Published: 21 October 2020 Abstract: Optical character recognition is gaining immense importance in the domain of deep learning. With each passing day, handwritten digits (0–9) data are increasing rapidly, and plenty of research has been conducted thus far. However, there is still a need to develop a robust model that can fetch useful information and investigate self-build handwritten digit data efficiently and effectively. The convolutional neural network (CNN) models incorporating a sigmoid activation function with a large number of derivatives have low efficiency in terms of feature extraction. Here, we designed a novel CNN model integrated with the extreme learning machine (ELM) algorithm. In this model, the sigmoid activation function is upgraded as the rectified linear unit (ReLU) activation function, and the CNN unit along with the ReLU activation function are used as a feature extractor.