Tagged Questions

Resolution is a term used in Image Processing. It is an umbrella term that describes the detail an image holds.

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Dynamic range resolution

I was wondering which is the dynamic range resolution in a audio digital system and I would like that you confirm or correct what I found out. I think there are two cases: Uniformly-quantization of ...
1answer
78 views

Reduce the number of frequencies after FFT

I have a long signal (1 day sampled at 500 Hz), which results in many frequencies if I calculate the amplitude spectrum (see e.g. here). However, I am only interested in the "big picture", let's say ...
1answer
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FFT Resolution Inference

Let's say I have an audio clip of $N$ samples. I want to describe every $10$ ms of audio with an FFT of size $1024$, without information bleeding over from other $10$ ms windows. Given that the ...
2answers
142 views

How do I get the Time information after STFT?

I'm tring to code a STFT program in Matlab. I got results but I'm confused a bit. I have a audio signal of 900000 pts sampled at 1000Hz (15 min signal). I've taken fft with following parameters => ...
1answer
67 views

How to increase the resolution of a video from a sequence of photos?

I have a video filmed in a relatively low quality and resolution and a sequence of photos of higher quality taken of the same scene at the rate of about one image every two seconds or so. Could those ...
0answers
46 views

Invertible multi-resolution representation of audio/speech signals

What are the invertible (preferably linear) representations of an audio/speech signal which captures the essence of signal in different resolutions and details. Basically, I am looking for Laplacian/...
1answer
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Sensitiviy and Resolution in Windowing Functions

When I read the article Windowing Functions, there are two terms that are does not understanding them well, sensitiviy and resolution. I looked for this two terms on the web, And I conclude that ...
1answer
138 views

WFM SDR and Audio resolution

How does SDR resolution translate to audio resolution when using FM demodulation? For example: using a 8-bit/2.048 Mhz IQ stream, what is the maximum audio sample rate and bit depth that can be ...
4answers
280 views

Selectively improve the frequency resolution of FFT (DFT)

I have a digitally sampled signal(sampling frequency = 4000 Hz) which contains analog frequencies from 0 to 1000 Hz. I wish to have a frequency resolution of 100 Hz(like 0,100,200,300 Hz .. 1000 Hz) ...
4answers
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Doppler Frequency Resolution for Radar

Doppler frequency is calculated by the formula $f_{d} = 2*v_{r}/\lambda$, where $v_{r}$ is the radial velocity and $\lambda$ is the radar wavelength. Normally FFT is used to detect the doppler ...
3answers
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Number of FFT points required for a specific frequency resolution for an oversampled signal

I have a bandpass signal centered at 2 MHz and bandwidth of 50 kHz (the signal frequency varies from 2 MHz - 25 kHz to 2 MHz + 25 kHz). This signal is being sampled at 10 MHz. I want a frequency ...
3answers
115 views

Does perceived ADC resolution, range and precision depend on fixed point format? What is the best way to deal with this for signal processing?

I am working on a system that is implementing a digital filter that was designed for another system that had an FPU and a 12bit ADC. The system that I am working on is using the same filter without an ...
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Signal Resolution

I have a question. Suppose we have a signal $x(n)$, length (samples) $N=400$ which have been sampled with $f_s=8000 \mathtt{Hz}$. Also suppose $X(k)$ - the DFT transform of this signal. How many ...
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216 views

Time-bandwidth product and uncertainty on harmonics

For a signal that is not corrupted with noise, how is the time-bandwidth product affecting the uncertainty or error introduced when extracting the fundamental frequency ? I mean, instead of choosing ...
1answer
358 views

Image processing and Camera Calibration

I have several related questions about camera resolutions. If I calibrate my camera to a particular resolution say 640x360, can I use it for another resolution like 1024x768? Also, I want to know as ...
3answers
2k views

When can we write Heisenberg uncertainty Principle as a equality?

We know that Heisenberg uncertainty Principle states that $$\Delta f \Delta t \geq \frac{1}{4 \pi}.$$ But (in many case for Morlet wavelet) I have seen that they changed the inequality to an equality....
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does Increasing resolution lead to have a poor resolution?

As it has proven in some paper and books the time and frequency resolution of Morlet wavelet is : $\Delta t=\frac{f_c\sqrt{f_b}}{2f_i}$ $\Delta f=\frac{1}{2\pi f_c \sqrt{f_b}}$ I don't know how ...
2answers
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Morlet wavelet time and frequency resolution

I want to calculate Morlet time and frequency resolution. the Morlet wavelet function is define as : $\psi(t)=\frac{1}{\sqrt{\pi f_b}}e^{j2\pi f_c}e^{-t^2/f_b}$ Note: I know the answers, but I don't ...
1answer
902 views

use chirp z transform for spectral resolution

let us suppose that we some signal $x(t)$,which consist of sinusoidal components and white noise,i would like to know how to use chirp z transform for improving spectral resolution?i found this ...
3answers
145 views

literature related to Spectral resolution

I am interested in spectral resolution of spectral estimation methods. Can you point me to some good literature, videos or books from which i can read and study? I want to understand how to resolve ...
0answers
24 views

Line rate and frame rate

I don't know how to determine line rate and frame rate of the following system: ...
2answers
38 views

Inverted values - digital resolution issue?

first of all, I am not a technician, but I would really appreciate your helping with one (I hope simple or trivial) issue. I recorded a signal (skin conductance level - SCL, uS unit) with my device - ...
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207 views

Artifacts in image after super resolution using delaunay triangulation in MATLAB

i have to do super resolution of two low resolution images to obtain a high resolution image. 1st image is taken as base image and the second image is registered with respect to it . i used SURF ...
1answer
719 views

Grayscale/Brightness Resolution vs Contrast

A bit of noob question, but can't find a definite answer anywhere: What is the difference between Gray-scale resolution of an image and the Image contrast. Are they different terminology for the same ...
2answers
552 views

Offset effect in FFT magnitude

i will use matlab code just for convenience, i get the same behavior using a C++ code. I have two signals: ...
2answers
278 views

How to construct an unknown signal from sparse periodic samples?

I have an unknown black-box that is generating a deterministic continuous periodic signal and the period is variable between 1 to 30 seconds. When the black box is turned on, the period is fixed, ...
3answers
240 views

Increasing image resolution

I know of some oscilloscopes (DSA8300) that repeatedly sample at a few hundred kS/s to reconstruct a few GHz signal. I was wondering if this could be extended to 2D signals (photographs). Can I take a ...
1answer
3k views

Does using the Goertzel algorithm actually give better frequency resolution?

I am reading this article, and I am getting a little confused by the author's liberal use of 'frequency resolution' regarding the Goertzel Algorithm. Basic question: Does using the Goertzel algorithm ...
1answer
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What is the maximal frequency resolution for Matlab's STFT implementation spectrogram()?

Matlab's spectrogram() function calculates the STFT of a signal. It describes its NFFT argument as follows: ...
2answers
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How are time resolution and signal bandwidth related?

I am confused by the dual concepts of time-resolution and bandwidth. Often I will hear that a pulse-compressed radar application 'doesnt have enough BW' for some specific time resolution that is ...
1answer
230 views

How can I estimate the spatial resolution of consumer grade electronics?

I have been looking at stereo vision applications, and one working example involves using two USB web cams, mounted together and calibrated. Is there a way to estimate the theoretical spatial ...