Although the current logic to eliminate the bouncing is far from perfect, let us go on to the next step.
The signals captured using SignalTap II can be exported as, say, a CSV file. Therefore, you can manipulate the data in various ways.
The waveform shows the first eight dots, the last one imcomplete, of consecutive dots.
Each length of marks and spaces is shown as a bar graph. Note that the value of 1,000 corresponds to 50mS.