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1. WAV FILE MORSE DECODER HOW TO
2. WAV FILE MORSE DECODER SOFTWARE
3. WAV FILE MORSE DECODER CODE
4. WAV FILE MORSE DECODER FREE

WAV FILE MORSE DECODER CODE

Why would a model created for handwritten text recognition work for Morse code recognition? He has provided excellent documentation on how the model works as well as references to the IAM dataset that he is using for training the handwritten text recognition. I took a Tensorflow implementation of Handwritten Text Recognition created by Harald Scheidl that he has posted in Github as an open source project. This is exactly what I did in the following experiment. The trained model can then be used to make the decoding from the input audio data.

WAV FILE MORSE DECODER SOFTWARE

So what does this new approach mean in practice? Instead of trying to figure out ever more complex software algorithms to improve your data processing and accuracy of decoding, you can select from some standard machine learning algorithms that are available in open source packages like Tensorflow and focus on building a neural network model and curating a large dataset to train this model. that tries to depict this difference between traditional programming and the new approach with Machine Learning. The computer then applies a training algorithm to this dataset that eventually discovers the correct "program" - the ML model that provides the best matching function that can infer the correct output, given the input data. As a ML engineer you need to curate a dataset that has a representative selection of input data with corresponding output data (also known as label data). From Morse decoder perspective this is how most decoders work: they take input audio data that contains the Morse signals and after many complex operations the correct decoded text appears on the screen. Depending on the complexity of the problem software developer may need to spend quite a long time coming up with the correct algorithms to produce the right output data. In traditional programming we look at the input data and try to write a program that uses some processing steps to come up with the output data. From software development perspective ML is changing the paradigm how we are processing data.

I have been quite interested in Machine Learning (ML) technologies for a while. In ham radio terms the difference of 47 dB corresponds roughly eight S units - human ears & brain can still decode S2 level signals whereas conventional software based Morse decoders produce mostly gibberish. Humans can still hear and even recognize the Morse code faintly in the noise. Computers equipped with these simplistic models have great difficulties decoding anything meaningful out of this signal. below shows "Hello World" with 35 dB signal-to-noise ratio that most conventional decoders don't have any problems decoding.įigure 2 below shows the same "Hello World" but with -12 dB signal-to-noise ratio using exactly same process as above to extract the demodulated envelope.

WAV FILE MORSE DECODER FREE

When the audio signal is noise free and there is no interference, these simplistic methods work fairly well and produce nearly error free decoding. The author has written many different software decoder implementations that use simplistic models to convert a sequence of "Dits" and "Dahs" to corresponding text.

WAV FILE MORSE DECODER HOW TO

The project is very complete, it works really well with the live recording What we learnedĪ lot about signal and iamge processing, how to use python audio libraries to open audio files, record audio and write audio files.I trained a Tensorflow based CNN-LSTM-CTC model with 5.2 hours of Morse audio training set (5000 files) and achieved character error rate of 0.1% and word accuracy of 99.5% I tested the model with audio files containing various levels of noise and found the model to decode relatively accurately down to -3 dB SNR level.ĭecoding Morse code from audio signals is not a novel idea. Yes, it's a little bit weird to use image processing techniques with signals, but is really useful in this case to see the problem as a binary row of an image. The signal processing was really interesting, I needed to use popular image processing techniques to create a robust process to avoid noise sounds. Using python in Anaconda Challenges we ran into The decoder allows you to decode a message from an audio file, a written message or a live recording. It consists in three parts, the encoder asks for a message in text, it translates the text to morse code and allows you to generate an audio file from it. Past technologies, many years ago the morse code was an important way to communicate messages, it's interesting to try to understand how this works What it does