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# Questions tagged [spatial]

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### What's the point of differential beamforming?

I recently got into differential beamforming, in particular into the work of Benesty and Cohen. It seems to me that differential beamforming is something that just "takes place" when ...
• 118
129 views

### Confusion sampling rate of a spatial array

I have 1D array data which is a horizontal pixel array with 2048 pixels with 12-bit values. So I can plot pixel number from zero to 2047 versus pixel values. But I need the FFT of that 1D array. But ...
• 171
60 views

### Reducing or removing autocorrelation in spatially correlated data

I am trying to figure out how one can reduce or preferably remove autocorrelation in spatially correlated data. Using the R code below, one generates spatially correlated data that is normally ...
• 1
1 vote
229 views

### How to reconstruct image from an Under Sampled MRI k-space data?

Hardware We have a homemade MRI machine (from the open source project openimaging). It has a single coil and B0 = 0.5 Tesla (enough for teaching). Sampling Mask We used a randomly generated sampling ...
• 123
470 views

### 2D Spatial Fourier Tranform on a pressure field

I'm doing some research on Fourier Near-field Acoustic Holography (NAH). The basic theory behind Fouerir NAH is that you take a sound pressure field measurement in a 2d plane p(x,y), 2d spatial ...
• 23
104 views

### What is the meaning of spectral contamination in image processing?

I resize the Multispectral image to perform IHS-to-RGB transformation. I used the Nearest Neigbour Interpolation method when resizing. While researching this issue, I saw that this is the best option ...
• 43
195 views

### How to detect the presence one- and two-dimensional patterns in distributions of spatial points?

I have many point patterns, and I want to detect those patterns that have points arranged in lines that may be curved, intersected or broken. For example, on the following picture, the upper left ...
523 views

### HRIR interpolation using VBAP

1) Problem description I am trying to implement a 3D audio simulator in Python. I am using the HUTUBS dataset as HRIR database (more informations here: https://depositonce.tu-berlin.de/handle/11303/...
62 views

### Are there standards/references for determining spatial scale in photographic images?

EDIT, 12/12/20: Images below are of the radial sinusoid pattern. Left side is the "unrotated" version. Right side is what the a photograph of the pattern would look like if the disc was ...
• 11
1k views

### Finding the equivalent filter H(u,v) in the frequency domain of a 3x3 spatial mask

I'm trying to find the equivalent frequency domain filter, $H(u,v)$, of a 3x3 spatial mask that averages all neighbours of a point $(x,y)$ in said 3x3 neighbourhood excluding the point itself. So far, ...
1 vote
129 views

### A hypercomplex encoding to preserve spatial/temporal information? [closed]

I have recently come across the idea of encoding a 1D signal (i.e. a mono audio) as a complex vector instead of as a vector of reals, where the imaginary part is used to encode the cells' positions. ...
• 11
653 views

### Spatial wavelength

I was reading a paper on motion magnification, Eulerian Video Magnification for Revealing Subtle Changes in the World by MIT CSAIL researchers, where the equation (14) of the paper uses spatial ...
• 480
374 views

### Combining two Images with Different Resolutions into Higher Resolution Image

I am attempting to combine two radar images, each of which is a 3-dimensional cube with a range dimension, an azimuth angle dimension, and an elevation angle dimension. One image has high azimuth ...
1 vote
338 views

### How to calculate spectrogram from nonstationary, nonuniformly sampled signal

I have a high resolution 3D spatial signal (xy-elevation data collected via Terrestrial Laser Scan) with very nonuniform sampling (holes/shadows due to vegetation; point spread varies as a function of ...
• 111
1 vote
625 views

### Signal and Space/Time

I have been reading a couple of definitions on signal such as: Any quantity measurable through time over space or any higher dimension can be taken as a signal. And this, In the physical ...
1 vote
2k views

### How to calculate the spatial frequency of an image in cycles per image

I have been attempting to calculate the spatial frequency of a colour image. I first converted it to grayscale and used a Fast Fourier transformation (fft2) that codes the quantity of each spatial ...
• 11
348 views

### How to prepare and plot unequally spaced, irregular data to a contour plot or similar with MATLAB

I've got a data set of hot-wire measurement velocity amplitudes at a given frequency bin (time data that has already been transformed to the frequency domain and I am just considering data for a given ...
• 1
1 vote
2k views

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