How denoise ECG signals like ECG-ID database?

I'm trying to implement an identification using ECG signal.

I found ecgiddb and I'm trying to reproduce the results.

In each single record of this database, there are two rows of data. The first row is the raw ECG signal and the second one is filtered signal as mentioned in database description.

Does anyone know how can I reproduce the second row using the first one? Does anyone has tries this before? What kind of filtering is used?

I have tried band pass filtering using a cascade of low-pass (fc = 40 Hz) and high-pass (fc = 1.1 Hz) filters, but its far away from the second row, which really is desired to me.

This is a sample record:

first row is raw ECG signal and second row is filtered ECG.

And this is a comparison between my filtered signal(first row) and database filtered signal(second row) for another record:

Thanks in advance,