the code you are using has sepecific format for finger print file reading. you are using dataset DB1 from 'FVC2002'. This contains file name as 101_1.tif, 101_2.tif, 101_3.tif, ..... 101_8.tif, 102_1.tif, ..... 110_7.tif, 110_8.tif. for that reson below format is used.
second=['10' num2str(fix((i-1)/8)+1) '_' num2str(mod(i-1,8)+1)];
if you are using you own dataset with diffent file syntax, then this wont work.
I have changed made some changes in 'main_single_new.m' and 'build_db1.m'.
Place those two file in you folder 'Simple_FingerPrint_Matching' and run 'main_single_new.m'
And one more in build_db1.m file formats I used is '.tif'.