Questions tagged [resolution]

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

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44 views

Weird resampling artifacts of a periodic signal

I am trying to grab time series data from a database storing data on a propritary format. When i chose a resolution which is not a multiple of the power of two of the sampling resolution i get these ...
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Multi Resolution STFT for audio

I am looking at trying to achieve a multi resolution STFT analysis on a log sine sweep audio measurement. I have an impulse, and I would like to perform two different windowed length FFTs on the ...
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34 views

Separability vs. Resolution - Synonymous terms?

In terms of discrete representation of a variable, let's say time measurements in absolute values in [seconds], is there a difference between separability and resolution? When do speak of either ...
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range resolution FMCW radar influenced by Nyquist?

I am puzzled about this for some time now. According to theory, the max range of a FMCW radar in practice is limited by the sampling frequency $R_{max} = \frac{c_0 T_{upchirp}}{2 f_{BM}}f_s$ Since ...
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Siglent waveform generator

I am using siglent waveform generator (model:6032X).. In the datasheet he has mentioned that it has 16-bit vertical resolution for 20 Vpk-pk. Will the ramp generated @700 mV have the same resolution ...
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110 views

Effective Nyquist frequency / signal resolution for overlapping time averaged signal samples

Say that I have a continuous signal. If I sample the signal at sampling rate f_sample, then the highest signal frequency that I can resolve without worrying about ...
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341 views

How to increase resolution of FFT?

I have an input signal in the ( 0 - 20 kHz ) frequency range . When i sample this signal maximum sampling frequency is around 40 kHz . When i calculate the FFT using 1024 points i got resolution of ...
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1answer
39 views

How do I add more resolution / taps to an analog -> digital filter?

(I am trying to create an IIR audio filter that adds reverb to an initial sample) Say I designed an analog filter to model acoustic attenuation based on the following mathematical model: $$ I = I_0 ...
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1answer
45 views

THD requirement for generated sine

I need to generate a sine signal using a DAC with a certain THD specification, say 0.1% @ 1KHz. As a first approach I’m considering it to be an ideal DAC along with an ideal LPF for aliasing removal ...
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1k views

How to increase the spectral resolution?

My question is about the spectral resolution of a discrete signal. Each sample of my signal is made up with 2^n frames sampled at 44.1 kHz. So, when I want to know the spectral resolution, I ...
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1answer
78 views

FFT radix-2 in audio - resolution issues - logarithmic scale - sample rate VS buffer size

I would like to ask how to deal with audio DSP. Is FFT good at all to deal with audio? I am working on an app, that generates a single impulse, rout it to an EQ plugin, and the output of the plugin is ...
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643 views

Basic difference between Multi-scale and Multi-resolution images

While working on Convolutional Neural Network (CNN) I saw many research articles working on the Multi-scale images. In the literature of image processing I saw there is also Multi-resolution analysis ...
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1answer
57 views

Most natural interpolation to simulate increasing distance?

Background: I'm generating multiple datasets with varying scales of resolution to simulate taking pictures from varying distances and then comparing image classification performances. For example ...
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Origin of brightness artifacts in intensity resolution compressed images

when compressing this image (It corresponds to Fig2.20 from the book Digital Image Processing by Gonzalez and Woods and the original .tif document can be downloaded through this link By reducing ...
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548 views

Minimum length of windows and separable signals

I created a signal with lets say $\omega_1$ that is fixed at 1 bin in the FFT: $$A_1\cos(\omega_1t)$$ I was asked to find the closest $\omega_2$ to $\omega_1$ so that the signals $A_1\cos(\omega_1t)$...
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1answer
26 views

How to go from high-res camera capture to low-res camera capture digitally?

Say, you captured a high-res image of a scene and a low-res image of the same scene, using a lower-res camera, ensuring that the lower-res camera is using the same technologies, except for the image ...
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129 views

fast fourier transform frequency limit [closed]

I'm a french student in engineering and I'm given a kind of mandatory technical project to work out on until February. I must investigate the following article : https://www.osapublishing.org/...
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2k views

Uncertainty principle - Duration bandwidth principle

In one of NPTEL courses about time-frequency analysis, the professor said that the duration bandwidth principle is $\sigma_t^2 \sigma_\omega^2 \ge \frac{1}{4}$. He added that the formula making use ...
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10k views

What are advantages of having higher sampling rate of a signal?

Being a non signal processing science student I have limited understanding of the concepts. I have a continuous periodic bearing faulty signal (with time amplitudes) which are sampled at $12\textrm{ ...
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1answer
115 views

Deciding on the FFT length for water waves in flume (wave facility)

Soon I'll be conducting experiments in a wave facility (flume) for my MSc thesis. And I would like to analyse wave spectra (amplitude and energy density). The time step (or 'accuracy') of the wave ...
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Where can I find more information about this formula relating a window's time and frequency size?

I remember having seen a formula of the form $C=\frac{B}{L}$ that relates a duration $L$(s) of a window to its width $C$(Hz) in the spectrum (defined at -3dB or so). The constant $B$ would be ...
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1answer
279 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 ...
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234 views

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 ...
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501 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 => ...
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1answer
111 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 ...
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66 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/...
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1answer
131 views

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 ...
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355 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 ...
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4answers
1k 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) ...
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13k views

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 ...
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3answers
196 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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125 views

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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481 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 ...
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1k 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 ...
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4k 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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214 views

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 ...
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2k views

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 ...
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1answer
2k 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 ...
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192 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 ...
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82 views

Line rate and frame rate

I don't know how to determine line rate and frame rate of the following system: ...
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2answers
46 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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316 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 ...
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1answer
2k 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 ...
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1k 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: ...
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329 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, ...
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337 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 ...
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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 ...
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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: ...
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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 ...
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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 ...