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Questions tagged [java]

is a multiplatform computer programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible.

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Mirrored Spectrogram Mp3

First of all sorry if this is a stupid question, but I am an absolute beginner in this field and have been trying for days now. I'm working on a java program that uses fft to analyze audio files. To ...
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1answer
132 views

What is the proper way to implement a real time spectrogram?

I am trying to implement a real time spectrogram and I am not sure that I am implementing it the right way. First I decided to use Matlab, I was taking a short recording of lets say 0.1 seconds and ...
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0answers
84 views

issue in the mfcc function in java and matlab,not the same

I am working on a project for recognizing and identifying the sounds in real time(like baby crying, birds, door knocking...)by java, so I made a model by using audio files for 9 categories of sound by ...
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2answers
641 views

How to remove lines from captcha image which are acting as noise using java?

The images are attached here. I first converted the sample image to grayscale and then binarized it. Finally i applied median filter to remove the dots from the image. However i am unable to remove ...
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0answers
34 views

How to give tones to a voice?

I am developing a sing synthesizer application. I planned some steps for it. Parse letters to characters/syllables. Synthesize the letters/syllables to files using ...
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0answers
74 views

low-frequency amplitude with phase modulation of low Hz carrier

I am writing an FM/PM synthesizer, using Java. For the most part it works pretty well. What I am curious about is an attempt to use a low frequency tone as a carrier. By low frequency, I mean in the ...
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1answer
211 views

How to smooth (or interpolate) phase of FFT and reduce data points

I am writing some code for audio analysis, and have currently got two signals with FFT performed on them. I get the phase of my complex array by using: ...
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1answer
92 views

Problems with IFFT not being symmetrical

I have two signals, a measurement and a reference which I have performed an FFT on. They have both been windowed with a Hanning window, and now I would like to deconvolve these to get the impulse ...
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1answer
504 views

Cross Correlation in Java (Android) Using FFT (Frequency Domain Convolution / Correlation)

I want to implement cross-correlation with the start-symbol and the signal using FFT. I zero-pad both signals to length N = x.len + y.len -1 Using the convolution theorem: ...
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0answers
18 views

Finding angles from an IMU (Quaternions to Eulers)

Greetings and apologies if this has already been answered, but I haven't been able to get a clear answer from looking on Stack Exchange so-far. I have Quaternions coming from two different IMU's ...
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2answers
349 views

FIR filter - remove padded zeros

I am using this class to filter EKG data. My sampling rate is 167/s and the length of data is 1670 (10 seconds), when I apply the filter I get the correct results but looks like the number of samples ...
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1answer
554 views

How to overlap two RAW audio signal

I hope I can find some help here. I have started working on a little project concerning voice recordings. What I would like to is: given two audio files in RAW format (or WAV, as long as I can ...
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2answers
451 views

FFT and IFFT : filtering frequencies

I am sampling at $30 Hz$. I have a sample of $N=150$. Here is an example of how my sample looks like, which starts at 54 and ends on 203 on the X Axis I am interested in observing frequencies ...
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1answer
2k views

Opencv Android Perspective Transformation not working as expected

I'm working with perspective transformation in opencv for android for a personal project. The thing I'd like to do is to acquire a document like CamScanner does. For this I import a picture and let ...
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1answer
517 views

Finding the fundamental frequency from Autocorrelated data

I'm writing an app in which I need to find the fundamental frequency of a note produced by a trombone. To do this I'm taking the FFT of audio data from a microphone and then using autocorrelation code ...
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1answer
1k views

How to perform an FFT on a signal with a sampling rate of 44100?

This is probably a very simple Signal Processing question but I can't quite work it out. I'm currently writing an android app which needs to perform an fft on audio data taken from the phone's ...
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1answer
144 views

Generating very short signals

So I need to program (using Java) some things that include generated sounds. I am struggling to understand how to make it work because I require a rather short signal while still using a sampling rate ...
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3answers
227 views

Performing DFT of streaming audio problem. Is there a limit?

I am trying to write software that will perform the discrete fourier transform of real time data coming from the microphone into the sound card on a computer. I am using Java with the javax.sound APIs....
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3answers
292 views

How to go about implementing a program to measure the “intensity”/“saturation” of a color in an image?

I have a task of developing an application to measure the intensity of a color in an image. I am researching about how to go about it. Intensity refers to the purity of a hue. Intensity is also ...
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1answer
127 views

How can I implement image widowing in my image in Java?

My initial image is a medical image and my main objective is finding directionality. The original size of my image was 8X8 and I have rescaled the image to 32X32 to increase my accuracy. My input ...
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1answer
460 views

How can I increase image size by zero padding?

For increasing the image size from 8X8 to 32X32, I tried to do zero padding. The simplest concept of zero padding in Java for me seems to be the code as shown below in Java such that I can shift each ...
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4answers
1k views

Advice on autocorrelation via FFT

I have been creating an application in Java that transforms an audio signal and writes it to a midi file. At first I tried using autocorrelation to find the fundamental frequency. However, I have ...
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1answer
397 views

FFT “Brick Wall” Low Pass Filter Not Smoothing Output

I'll try to be as brief as possible. I have very limited signal processing experience. I have a data set that consists of essentially a big old sine function (with deviations from ideality), and lots ...
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1answer
723 views

How to set sampling frequency of an acceleration data set

I have a set of accelerometer readings in $X, Y, Z$ axes obtained from an android based smart-phone. The data in $(X, Y, Z)$ was recorded at different time stamps and there is no uniform time period ...
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1answer
727 views

3D intensity map for grayscale image

I've got images of blood drops in grayscale and I want to generate 3D data where the first two dimensions represent the area of interest and the 3rd dimension represents the pixel intensity of that ...
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0answers
2k views

Compare two voices and outline their similarity

I am trying to develop an application which records the voice of someone through a microphone. I will have a preset recorded voices for the same words. I then need to compare the real time recorded ...
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1answer
851 views

How do I implement LIBSVM for multiclass classification using java?

I am currently working on an image classification project ,where i need to use bag of features model with libsvm(HIK kernel) for classification.I have extracted sift feature and created a visual ...
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1answer
884 views

How to implement anisotropic diffusion using java?

I am working on an image processing project in java where we use anisotropic diffusion for scale space generation. In the below equation, after finding the diffusion value.using the second equation, ...
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2answers
134 views

Fixing my FFT Plot

I'm trying to plot my FFT of File. This i my result. I made my FFT application: I want to obtain something very similar to plot of WaveSpectra, please tell me my mistakes.. My FFT The result from ...
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2answers
1k views

Upsampling PCM audio: from 6 kHz to 8kHz

What would a straight-forward way to convert an audio payload (PCM 16bit) from 6 kHz to 8kHz? I understand that this is an interpolation problem. I fear that a linear interpolation would introduce ...
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1answer
731 views

Formulas to plot Frequency Impulse Response Coefficients

I made this question https://dsp.stackexchange.com/questions/19731/newbieplotting-fft-and-impulse-response-coefficients-using-java I have the IRC: Impulse Response Coefficients: $h(k), k = 0, 1,.., ...
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2answers
992 views

Is it necessary to apply some window method, to obtain the FFT? Java

I read that the window is needed to apply filter (Low Pass, High Pass, Band Pass or band Stop), but not for the FFT. 1. What advantage does apply a window or disadvantage does not apply? 2. What ...
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2answers
933 views

FFT calculation suitable, Wav File, Java

If I have a wav file with this characteristics: 16bits (2 Bytes per Sample) 32000 Sampling Rate 60 Seconds 2 Channels then I have: ...
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1answer
1k views

Improving an auto-correlation based guitar pitch detector

I've seen many questions on this forum regarding pitch detection for musical instruments (commonly guitar), and spent a while reading through the answers to create a basic implementation of auto-...
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2answers
825 views

Android: fundamental frequency

I want to find the fundamental frequency for human voice in an Android Application. I want to use autocorrelation method. My code is this: ...
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2answers
2k views

Correlation Using FFT / IFFT (Convolution in Frequency Domain) in Java

I try to find about the delay between two audio files using Cross Correlation in Java. I've already done this algorithm so far that i get a idea about how many samples is the delay. FFT x1 -> Zero ...
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1answer
2k views

Java amplitude processing

I have some code that collects amplitudes from a complex sound like a song. I now want to plot a graph of amplitude vs time, for the graph plotting I use JavaFX. However I get about 9 million ...
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2answers
139 views

possibilty of extracting a tone from MIDI values

I have a project of recording human's sound via Android's SoundRecoder API, and then displaying the extracted note on The screen. It is specific for Android platform (can't use Jmusic or Jfugue API as ...
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2answers
42k views

How to analyze audio input/spectrum correctly

I am quite new to Java and Signal Processing, but I was assigned a project dealing in audio processing. My topic given to me is a game that has a component of analyzing a song (any given song) and ...
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1answer
2k views

Preparations to implement FFT on a wav file (code Java, not Library)

I am making preparations to implement FFT on a wav File.wav Only Java. I'm reluctant to use matlab I have a File wav stereo, 16 bits. I need to calculate the FFT, but I have confusing. My File has ...
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3answers
3k views

Hilbert-Huang Transform Implementation

I am looking for a implementation of Hilbert-Huang Transformation. Ideally, in Java, but any language with similar syntax would prove useful. Could someone point me to a specific implementation, ...
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1answer
1k views

is root mean square possible to calculate similarity of FFT result?

I need to compare FFT result from audio files, I have 2 FFT result from 2 audio files.. FFT 1 (sample) ...
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2answers
2k views

Matching 2 audio files

I'm doing research on how we can do matching between 2 audio files using Android to see if they have the same content or not. After doing lots of research, I have concluded that I must do 2 main ...
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2answers
235 views

Noise from CPFSK

I am programmatically generating a CPFSK encoding, and between shifting from two frequencies, there is extra noise generated by my speaker. For instance, going from 18375hz to 18900hz, there is extra ...
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3answers
2k views

Detecting a single frequency in noisy data

I am not very experienced in signal processing, and it seems like this should be a simple problem. I have two computers, one plays a tone a 19 kHz at a sampling rate of 44.1 kHz, and the other listens ...
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1answer
5k views

How to determine ALPHA, smoothing constant, of a LPF?

I am implementing a simple LPF in Java. But I have problems in choosing the value of ALPHA. ...
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1answer
1k views

SineWave generation and BandPass filter : Audio

Can any one suggest me a Bandpass filter in java which I would like to apply on generated sine wave of a particular frequency
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1answer
246 views

Image restoration using java [closed]

i am working in digital image restoration field, i am familiar with java and i want to use java in image restoration, can any please suggest me any book or tutorials where i can learn about image ...
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2answers
3k views

How can I identify Arabic letters in an image using Java?

I want to identify Egyptian car number plates that look like this: How can I do this in Java ? I plan to do this in Android, as the user will catch the number plate with a camera and the results ...