1. Title of Database: Optical Recognition of Handwritten Digits Original, unnormalized version. 2. Source: E. Alpaydin, C. Kaynak Department of Computer Engineering Bogazici University, 80815 Istanbul Turkey alpaydin@boun.edu.tr September 1998 3. Past Usage: C. Kaynak (1995) Methods of Combining Multiple Classifiers and Their Applications to Handwritten Digit Recognition, MSc Thesis, Institute of Graduate Studies in Science and Engineering, Bogazici University. E. Alpaydin, C. Kaynak (1998) Cascading Classifiers, Kybernetika, to appear. ftp://ftp.icsi.berkeley.edu/pub/ai/ethem/kyb.ps.Z 4. Relevant Information: We used preprocessing programs made available by NIST to extract normalized bitmaps of handwritten digits from a preprinted form. From a total of 43 people, 30 contributed to the training set and different 13 to the test set. Inputs are centered and normalized as 32x32 bitmaps. In optdigits, Training, Validation and Writer-dependent sets are combined to form one large training set and the Writer-independent set is the test set. There to decrease dimensionality, 32x32 bitmaps are low-pass filtered and undersampled to get 8x8 integer matrices and converted to UCI format. This optdigits-orig is in the original format following that of NIST. For info on NIST preprocessing routines, see M. D. Garris, J. L. Blue, G. T. Candela, D. L. Dimmick, J. Geist, P. J. Grother, S. A. Janet, and C. L. Wilson, NIST Form-Based Handprint Recognition System, NISTIR 5469, 1994. 5. Number of Instances optdigits-orig.tra Training 1934 optdigits-orig.cv Validation 946 optdigits-orig.wdep Writer-dependent 943 optdigits-orig.windep Writer-independent 1797 All files contain a header which include relevant information. See NIST TR for details. 6. Number of Attributes 1024 input+1 class attribute 7. For Each Attribute: All input attributes are integers in the range binary '0'/'1' with '\n' at the end of each row to visualize input. The last attribute is the class code 0..9 8. Missing Attribute Values None 9. Class Distribution tra cv wdep windep Class 0 189 87 100 178 Class 1 198 97 94 182 Class 2 195 92 93 177 Class 3 199 85 105 183 Class 4 186 114 87 181 Class 5 187 108 81 182 Class 6 195 87 95 181 Class 7 201 96 90 179 Class 8 180 91 109 174 Class 9 204 89 89 180