To noiseprint an audio file, find a fragment of the file which contains only the background noise (analog tape hiss, surface noise of a vinyl record, etc.). The material suitable for a noiseprint evaluation can be usually found at the very beginning of the recording (a piece of "silence" preceding the recorded signal) or at the very end.
To take a noiseprint:
1. Select the source soundfile by clicking the corresponding SOURCE
button.
2. Select a block of reference noise samples (the minimum size of the block is 2048)
3. Access the NoisePrint Manager dialog by choosing the NoisePrint command (available from the Restore menu) or pressing the NoisePrint Manager button situated at the top of the DeNoise Plus dialog.
4. Press the Take button placed inside the NoisePrint Manager dialog. After evaluating the noise characteristics, DART XP Pro will create a temporary noiseprint ID file. The noiseprint curve will be displayed at the top of the DeNoise Plus dialog.
Using the NoisePrint Manager dialog you can add a newly created noiseprint (Anonymous) to the DART XP Pro archive of noiseprints (Add), remove it from an archive (Remove) or assign it a new nickname (Rename).
If the noise sample is at least half a second long DART XP Pro saves its fragment and allows one to listen to it each time the corresponding noiseprint is retrieved from the archive (use the Audition button for this purpose).
To transfer noiseprints from one computer to another use the Export and Import buttons.
The procedure for noiseprint extraction is extremely efficient and works satisfactorily for even very short reference noise samples. For this reason you will not observe a dramatic improvement of the restoration quality when the size of the noise snapshot is increased. Obviously, however, the noiseprinting procedure is more reliable with longer noise samples.
NOTICE 1
DART XP Pro will not allow you to use a noiseprint which doesn't match the processed audio file in terms of the sampling rate or sampling resolution. However, it will accept using a mono noiseprint when processing a stereo soundfile and vice versa.
NOTICE 2
Information about all noiseprints (any number of noiseprints can be collected) is stored in the configuration file dartwin.npl. The noiseprint archive can be damaged if this file is deleted or corrupted outside DART XP Pro.
You can use the DeNoise Plus dialog to modify an existing noiseprint. To change the shape of the noiseprint curve drag the plot nodes up or down, which is equivalent to increasing or decreasing noise attenuation in selected bands. To insert a new node click on the plot using the left mouse button. To remove an existing node click on it using the right mouse button. After pressing the SHIFT
key and placing the cursor over any node, you will be able to drag the entire plot upwards or downwards. If you wish to extend changes to frames of all sizes press the Extend button.
When dealing with stereo recordings you can separately modify noiseprints of the left and right channel after pressing the Left and Right button, respectively. If you click the Left+Right button the average: (left+right)/2 noiseprint will be displayed - in this case all changes will affect both channels simultaneously.
After finishing the noiseprint modification press the Set button - otherwise the introduced changes will not be preserved when you close the DeNoise Plus dialog. For your convenience the details of the original noiseprint proposed by the system can be restored at any time by pressing the Reset button.
NOTICE
If there is no material for the noiseprint evaluation try using a “typical” noiseprint curve available after pressing the Default button.