One group expanded the database, worked on better averages and organised our files. Playrec was discovered and installed.

The second group worked on matlab functions for comparing 3 different keys. 2 methods were being used: MSE(Mean Square Error) and PCC(Pearson Correlation Coefficient). The functions worked most of the time, recognizing the key(input). Errors were most likely due to noise on the used samples. We made this conclusion on the fact that whenever it returned the wrong key, the corresponding correlation was significantly lower.

The last group worked on creating a program that could detect keypresses. In other words, it could distinguish a key being pressed on a keyboard and a random noise. It also seperated the different keypresses from eachother, so each one could later be analysed. The function had a 92% accuracy when analysing a clear recording. However when analysing a file that had no keypresses, but only random noise, yelling and talking, it detected 25 keypresses. Since this recording was 15 seconds long, this means that out of 100 tests, 33 false positives were found.

The function clearly needs to be optimised.

We refined our algorithm of hitpeak and made a new one regarding the average of one letter(A) (in the domain of time).

We analysed our average and thought of different ways of recognizing which letter is being pressed.

Next week we will divide ourselves into 2 groups, working out two solutions we found about this problem.

We worked out a function for reading, plotting and transforming the signal to the frequency domain. We thought this would be the best way to quickly 

extract the essentials we need from our signals. We also found an algoritm for finding the 'touchpeak' from the signal, the one we need.

This is usefull, because we now can start comparing multiple samples from each key. (we already have 20 samples of the key "a")

We could not yet find a way to directly save the important plots (the one from the frequency domain) to a file, so we could open them all together and compare them. This we will search for next tuesday.

We still are wondering how to compare the frequency-plots, wether we have the right part of the signal, and if these frequencies are correct...