How WIDI works
WIDI is a complex system and it contains different algorithms for different steps of music recognition process.
There are two types of algorithms - Note Detection algorithms and Supplementary algorithms.
Current WIDI contains three different Note Detection algorithms - they are Euclid, Drum Detection and Advanced sensors. Their task is to extract actual note data. Euclid and Advanced Sensors are general-purpose algorithms, and Drum Recognition performs only recognition of percussion instruments.
Different algorithms perform differently, and every algorithm has its own advantages and disadvantages. The performance of the algorithms is mainly affected by Wave->Pitch, Pitch->MIDI Recognition Settings pages and Equalizer.
Supplementary algorithms allow to identify additional features of the composition, and this helps Note Detection algorithms to work better.
Currently Supplementary algorithms include Tuning Determination and Tonality Determination. These algorithms are controlled from the Tuning and MIDI Options tabs of the Recognition Settings and from Scale Mask Equalizer tab.
Some properties of the resulting MIDI file that are not detected automatically can be set using MIDI Options tab. This parameters are assigned to result MIDI "as is". All of them except tonality are not used during recognition.
Supplementary algorithms works together with Note Detection algorithms, and resulting recognition sequence can be very complex.
Here is the list of undertaken operations if Try to detect Global Tuning, Determine Key Automatically and Use Recognized Key features are turned on:
In less complex situations (for instance, if Determine Key Automatically is off) some steps are not performed.
You may need several recognition attempts to get reasonable recognition quality. Usually you start from some predefined recognition settings and then adjust them corresponding to recognition flaws you hear. After several attempts you find some setup when you cannot achieve substantially better quality by modifying parameters. At this point you take the best recognized variant and then export it or edit it manually. A very convenient way to do editing and correction is the internal TrueTone Editor available in WIDI Professional.