Questions tagged [distance-metrics]
The distance-metrics tag has no usage guidance.
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What distance metric can I use for comparing image features in a nearest neighbour algorithm?
I use Nearest Neighbour function of Scikit learn module in python for training and compare an image set (https://docs.google.com/file/d/0B6zJ3_hrkW40U182SWNWX3o4dE0/edit?usp=sharing&pli=1)
By ...
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Fastest Algorithm for Distance Transform
I am looking for the fastest available algorithm for distance transform.
According to Image Processing Learning Resources - HIPR 2 (HYPERMEDIA IMAGE PROCESSING REFERENCE) - Morphology - Distance ...
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Images similarity measure using Jeffrey’s Divergence (j Divergence)
I need to reproduce the result of Xu, Xiaocong, et al, 2016 paper . Mutual information code already was done and work fine. Can anyone help me to write Jeffrey’s divergence code? Because the I use ...
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Is `xcov()` More Accurate Than `xcorr()` to Compute the Cross Correlation of Signals with Non Zero Mean Values?
I have to compute the cross-correlation between two transient signals, which could be decomposed into a trend (with non-zero mean value) + noise.
In particular I am interested in the max of the cross-...
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Good metric for qualitatively comparing image patches
I am trying to "match" little square patches in an image. At first glance, it seems reasonable to simply do a Euclidean distance style comparison of two of these arrays to get a "similarity" measure. ...
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raw values or distributions as input to wasserstein_distance - python
I asked a question in SO regarding what kind data I should pass to the wasserstein_distance function from the scipy module.
The documentation says that the input data are "Values observed in the (...
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Minimum distance question
I´m reading a paper on Miller codes and I´m having trouble calculating the minimum distance out of a state diagram.
The paper states in Fig. 3. that "it is easy to verify that dmin for these ...
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Evaluate two lossy compression algorithms
I am trying to evaluate several methods to compress some 2D data points. The algorithm itself is not relevant, but from the output, I can compute the MSE and the number of points (which can be used to ...
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What is a good distance measure for matching SIFT descriptors depending on the distribution of their noise?
I have read some papers about distance measures like Euclidean, Manhattan or Chi-Square for matching gradient based image descriptors like those computed from the SIFT Algorithm (128-D vectors). Most ...
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What Distance Measure Is Proper for Image Patches?
I have a bunch of image patches extracted from two images.
I want to find a proper measure of similarity between each patch from first images to patches from second image.
I have made vectors from ...
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What is the condition under which the length of shortest 4-path equal to $D_4$ distance?
The following is a problem of "Digital image processing" book.
Consider two points $p$ and $q$. State the condition(s) under which the $D_4$ distance between $p$ and $q$ is equal to the ...
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Looking for pratical quantitative comparison metrics for scaled, delayed and warped Signals
[Nota: I have validated the only answer so far, yet more explicit versions are still welcome]
The following question is detailed in 1D, with time as the ordinal variable. Similar questions could apply ...
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What distance metric can I use for comparing images?
I usually use the mean squared error (MSE) or peak signal-to-noise ratio (PSNR) to compare two images, but this isn't good enough. I need to find a formula that returns a very big distance between an ...
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Find which signal was transferred in 32QAM
I've been assigned to solve a problem for 32QAM signals. The thing is, there are little to none sources in my native language to get any decent information on the topic.
The problem is (in its ...
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Semantic Distance Measure Between Images
I would like to compare 2 generic images, with same sizes and normalized values. Which metric would be better than the baseline Eucledian distance?
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Mahalanobis Distance For Pairwise Distance
First post here so please be easy on me.
I have an application where I have one data point in high dimensions, represented by an $m \times n$ matrix. Call it $X_1$. And I have to compare this data ...
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Gaussian weighted distance between pixel amplitudes: motivations and sources?
In several image processing papers, and for instance in Random Walks for Image Segmentation (2006) by Leo Grady, changes in image intensities are turned into edge weights. In some fields, it is called ...
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Is maximizing hamming distance the same as minimizing correlation?
For the design of an error correcting code, I might wish to maximize the distance between the codewords $\sum a_i \oplus b_i$.
For spreading sequences I'd like to minimize the cross-correlation at $t=...
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PSNR calculation with float arrays
The PSNR definition provided by wikipedia is often quoted in discussions regarding PSNR and other similarity metrics.
Essentially the PSNR calculation has two components: the mean squared error and ...
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Can the colors of an image be interpreted as "virtual" Doppler effect? [closed]
In astronomy, the Doppler effect is used to estimate approximate distances to stars and other celestial bodies.
Using the same principle, lets say we divide an image (photograph) in pixels and that ...
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Range Estimation Based on Distance Differences
It is a range estimation problem, as shown in the figure.
The blue circles are the anchor node' positions, which are produced by one moving anchor (the moving direction is shown with black arrow). ...
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Metric Spaces: Why $L_\infty$ selects the maximum value
I have a basic question about the metric spaces. There are several metric spaces like $L_1$, $L_2$ to $L_\infty$. The $L_p$ metric is defined by the following equation:
$$d_p(x,y)=\left(\sum_{i=1}^{n}...
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Image registration / fusion optimal similarity metrics
I have a theoretical question about optimal similarity metrics for comparing data sets.
In reading this linked paper, pp. 488-489 [1], I read the following 2 interesting statements. On page 488:
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Is SSIM a measure of mutual information?
As i have seen contradictory information online: is the quality measure SSIM between two images (one base-line, one distorted) directly correlated to the mutual information between the two. One one ...
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nearest neighbor implementation matlab
I am trying to implement this research paper:
I understand everything in the paper except the part about the nearest neighbors calculation (section 3).
The only MATLAB function I can think of that ...
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Measuring similarity between two very similar pictures
I know similar questions have already been asked, but as I understand, little differences in my goal make a difference on a decision on which algorithm to use. As I am a total novice in this area, I ...
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Affine Transformation for matching 2D point sets
I have two sets of 18 corresponding 2D points. These coordinates represent the main joint points of a human body, describing the "human pose".
I want to decide if these two poses are similar/have the ...
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Distance from an object.. Where is the camera origine?
I compute the distance from an object (Chessboard) using OpenCv and my camera parameters using those steps:
findChessboardCorners
solvePnP
->Distance
The distance I get is between two points: the ...
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Comparing two colored lines
I have two colored lines, which can be thought of as functions I1,I2:[0,1]->R. I want to check whether I1 and I2 'topologically' represent the same object. In other words, if I stretch some parts of ...
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Distances In a Single Image With Some Real References
Consider following image:
We have some real references here: Stonehenge measurements (stone dimensions and distances), some strait lines at the back of carts, cart wheels that are almost of the same ...
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How to determine relative distance between 3 in-phase transmitters by analysis of received signal
I would like to determine with high accuracy the relative distances between three RF transmitters a few meters apart by analysis of phase interference in the received wave, the receiver being at an ...
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"Circular shift - invariant" distance
Couldn't decide whether the question belongs on Mathematics or here, but I guess I'll ask it here.
I've got a discrete - valued function defined on a finite segment of a line that looks like this:
...
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Measuring typical seperation between patches using 2D Fourier Transform
I need to extract information about the typical distance between the black patches in an image like the one I attached here. Typical distance would be the the most frequent separation between two ...
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Increasing Recall rate for SIFT
Is there a better way to increase Recall Rate when using SIFT features?
I am thinking a way to replace the NN1/NN2 ratio to account for slightly distorted objects.
Moving towards clustering and using ...
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Good color distance metric for classifying color pairs
I have some two tone origami paper. This particular paper comes in six types, each with a different pair of colors. Here's an image that shows all six:
Given a picture of one of these sheets, I want ...
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Comparing two signal outputs from two clients on a networked computer game to identify lag
Basically, I'm running a server and two clients of the Unreal Engine and trying to figure out if there is lag in player movement on one of the clients (the clients are different in way that's not ...
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understanding image error metrics, mean squared error
i am trying to understand the error metrics for images. i had no statistics class or anything and i'm having a bit of problem with even the simplest things.
i have started reading this http://...
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Measuring with OpenCV and OpenNI
I'm playing with the built in OpenNI access within OpenCV 2.4.0 and I'm trying to measure the distance between two points in the depth map. I've tried this so far:
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Distance-metric for SIFT descriptors matching
Will using Cosine-Similarity or Histogram Intersection as distance-metric, for matching SIFT descriptors, help to get better results?
Anybody tried on that ever?
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Combining Distance Maps
I have two distance maps that describe distances from blue segment and the red segment. I need to compute a single weight map that describes transition from blue segment to the red segment. The weight ...
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Black box signal prediction
I have a stateful black box with four real-valued inputs and one real-valued output. My problem is to predict the output at each moment in time, given the sequence of inputs seen up to that point. ...
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Are there any good "conceptual distances" for comparing two images?
I want to define some distances to use over an image, which I create.
I think I need to define two different "distances".
The first distance should be the most robustness preserving in compare to ...
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