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Questions tagged [quantization]

Use this tag for questions related to quantization of any kind, such as vector quantization.

Quantization, in mathematics and digital signal processing, is the process of mapping a large set of input values to a (countable) smaller set.

For more, please read the Wikipedia article for more.

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Color extraction, quantification and analysis from image in R

I would like to quantifying colors in an image. I work on the iridescence of nacre (mother of pearl), and I want to quantifying three colors (red, yellow and green) on this shell (for example on the right picture on the link above). Iridescence of…
Pierre-louis Stenger
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Algorithm To Quantify The Difference Of Line Segment Paths

Say I have two line segment paths, such as a subset of the examples below. How can I quantify the difference between them? |__ \_ __ /\ \/ | _ The two paths may have a different number of segments, and the length of each segment and the angle…
Craig Younkins
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Why we need a coarse quantizer?

In Product Quantization for Nearest Neighbor Search, when it comes to section IV.A, it says they they will use a coarse quantizer too (which they way I feel it, is just a really smaller product quantizer, smaller w.r.t. k, the number of…
gsamaras
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k* reproduction values?

I am reading about Product Quantization, from section II.A page 3 of PQ for NNS, that says: ..all subquantizers have the same finite number k* of reproduction values. In that case the number of centroids is (k*)^m where m is the number of…
gsamaras
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Quantize Embeddings

I would like to quantize embeddings to a single signed byte in each dimension. If I try to do this by scaling the values to [-127, 128], then casting to tf.int8, recasting to tf.float32 and rescaling to the original [-1, 1] range, I get the…
RobR
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(Python) How could I influence PIL's image quantification choices?

I'm running the code below to remove unwanted gradients between uniform color patches. This works well enough in plenty of cases however sometimes it fails because of the similarity of some gradient colors and the palette colors, like in the image…
MapEngine
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Self organizing Maps and Linear vector quantization

Self organizing maps are more suited for clustering(dimension reduction) rather than classification. But SOM's are used in Linear vector quantization for fine tuning. But LVQ is a supervised leaning method. So to use SOM's in LVQ, LVQ should be…
clarkson
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Quantizing a complex signal with uniform quantizer in matlab

I have a signal that has complex normal distribution with mean 0 and variance of 1. I want to quantize it with a uniform quantizer to 512 levels. I am generating the signal in MATLAB in the following way- s = sqrt(0.5).*(randn(1,numBits) +…
rmb
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Getin range while using uencode() function in Matlab

I'm using uencode to quantize matrix this way: quantized = uencode(impact_factor_matrix,5); where impact_fator_matrix is a 512x512 matrix of floating point values basically between 0 and 3 a small fragment of this matrix looks like…
hesar
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Sampling / Quantization / PCM networks

Suppose an analog audio signal is sampled 16,000 times per second, and each sample is quantized into one of 1024 levels. What would be the resulting bit rate of the PCM digital audio signal? so that a question in Top down approach book , i answered…
Injy Sarhan
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Python - Clustering MFCC Vectors

I am currently doing a speaker verification project using hidden markov models no accurate results on voice signals yet, though i have tested the system to various data samples (not involved with voice). I extracted the MFCC of the voice signals…
Bobby
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How to quantize surface normals

I am trying to quantize surface normals into let's say 8 bins. For example, when computing features like HOG to quantize 2D gradients [x,y] into 8 bins we just take the angle with the y plane i.e. arctan(y/x) which will give us an angle between…
Aly
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How to use ColorQuantizerDescriptor?

Following the idea of @PhiLho's answer to How to convert a BufferedImage to 8 bit?, I want to use ColorQuantizerDescriptor to convert a BufferedImage, imageType TYPE_INT_RGB, but RenderedOp#getColorModel() is throwing the following…
Daniel Trebbien
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Jpeg quantization table (16x16)

I try to study jpeg image compression. I've got one problem for quantization step, I am not able to find quantization table for matrices 16x16. I am searching for the matlab code for JPEG quantization table (16x16) for digital image compression…
Adi Prasetio
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Custom Image Format: How to Target Compression Algorithms

I've done a bit of fiddling around with PNGs over the last couple days and I am upset with my findings. I'm concluding that the majority of my results deal with compression. So this weekend I'm going to dive into advanced compression articles. I…
Almost Famous
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