A form of signal processing where the input is an image. Usually treating the digital image as a two-dimensional signal (or multidimensional). This processing may include image restoration and enhancement (in particular, pattern recognition and projection).

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15 views

normalization of data points in order to make them adhere to a specified probability distribution (e.g. Normal)

I am doing some preprocessing for a computer vision task. My target is to select a few elements (pixels) containing highest scores according to a metric that I am developing. The values of this metric ...
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10 views

Bilinear interpolation to calculate the summation of vectors [closed]

How can I use bilinear interpolation to calculate the summation of these vectors? ...
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0answers
8 views

Need to order a set of colors to build a feature vector

I am working on Computer Vision task of object classification with python and OpenCV. Currently I am extracting some characteristic colors of an image using K-means clustering on all the pixel to ...
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0answers
14 views

How to interpret FPPI

I am struggling when trying to interpret this graph (it represents pedestrians detection accuracy in images for several algorithms) The horizontal axis represents the False Positives detected Per ...
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0answers
23 views

Collection of features that correlated with strength and elongation of nonwoven fibers

I'm working on a regression problem which estimates strength and elongation of a non woven fibers by using some features collected from processed images of the fibers. For this study I've collected 50 ...
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2answers
58 views

Classification Algorithms

Rather than due a google search and hope to find "the best" or an exhaustive list of classification algorithms I thought it might be easier to pose my questions here, and then get advice from you ...
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17 views

Algorithms for invariant image recognition

I am interested in the current state of affairs when it comes to image recognition. I am particularly interested in algorithms that can handle a high degree of invariance. Except for Artificial ...
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0answers
12 views

Image analysis classification where images are of different dimensions, resolutions, etc

I am working on an image classification problem where I have black and white images of all different dimensions and resolutions. The images belong to 1 of 5 groups including an unknown category. These ...
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1answer
42 views

Probability of a model given an image

I would like to write the likelihood function for an image with respect to theoretically predicted values. Assuming uniform Gaussian noise, the pixels are statistically independent, and we can write a ...
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1answer
83 views

Eigenfaces in R: How to reconstruct original features from principal components? [duplicate]

I've performed PCA on face images dataset and I'm not sure how can I use the most informative principal components to show the "reduced" image. The original image is 96*96 pixels (96*96 = 9216) and I ...
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79 views

Naive Bayes Nearest Neighbor (NBNN) implementation problems in MATLAB

I'm currently trying to classify the CIFAR-10 image dataset. I cam across a number of papers praising the the results from a non-parametric approach called Naive Bayes Nearest Neighbors. It uses SIFT ...
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9 views

Find input image (ID,passport) in imagesDB based on similarity

I would like to decide if image is exists on DB images (pictures of IDs,passport,Stu. card,etc) I thought of KNN alghorithem that will plot the K closest images. Options for distance metric: 1) sum ...
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2answers
149 views

PCA on train and test datasets: should I run one PCA on train+test or two separate on train and on test? [duplicate]

I'm doing an image classification task and the number of features of each example image is pretty huge (3,072: # pixels in each image). I'm thinking of using PCA to reduce the # features of each image ...
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28 views

Query on “Deep neural networks for object detection”

I was trying to follow the paper "Deep neural networks for object detection" at http://web.missouri.edu/~hantx/ECE8001/Presentation_papers/Deep%20Neural%20Networks%20for%20Object%20Detection.pdf. I ...
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0answers
22 views

Gabor filters: Large variance compared to the mean

I am trying to extract Gabor features from an input image. So, I have setup a series of Gabor filters with different parameters (frequency, angle and standard deviation) and I am convolving each of ...
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0answers
41 views

Compare 2D maps

I have a bunch of samples to compare. Each sample is composed of 30,000 cells (dots) for which I computed 2 dimensions (30,000 x 2 matrix). Each dot represent the expression of two parameters for a ...
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0answers
18 views

Combining features extracted from different parts of the same image

It is about car identification in images. I have an 64x64 image divided into 16 equal windows. I compute a HoG features algorithm in each one. And I am using the concatenation vector resulted from ...
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1answer
42 views

find the optimal correspondence matrix

I have two sets of points and I find with different methods, different correspondence matrices which shows which point in one set correspond to other point in the other set. How could I find the ...
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1answer
89 views

how to superimpose two matlab images rigidly transformed to perform a metrics

i got two MRI images on matlab, i need to perform an intensity based registration similarity metrics in order to get a registration. The problem is that, since i got some rigid transformation on one ...
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2answers
2k views

What is the difference between ZCA whitening and PCA whitening?

I am confused about ZCA whitening and normal whitening (which is obtained by dividing principal components by the square roots of PCA eigenvalues). As far as I know, $$\mathbf x_\mathrm{ZCAwhite} = ...
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1answer
84 views

Breaking black and white captcha

I am looking for a way to break this kind of captcha: I know that there are always 4 digits, in black and white. The image basically consists of an easily recognizable 4-digit code, mixed with a ...
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0answers
31 views

Neural Network & Image recognition - preprocessing

I have a project where I´m supposed to recognize ordinary data written numbers (1-10) from images as well as some geometrical shapes (rectangular, triangle, circle, etc.). However, I´m not sure about ...
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1answer
45 views

Question of unary term (data term) of the graph cut method

I am trying to apply graph cut method for my segmentation task. I found some example codes at Graph_Cut_Demo. Part of the codes are showing below ...
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0answers
23 views

Definition of the deterministic annealing method

iI have ran into a shape matching problem and one term which I read about is deterministic annealing. I learnt that it would help to convert discrete problems, e.g. ...
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0answers
21 views

Which terms are more standard: precision and recall or correctness and completeness?

I am familiar with terms like precision rate and recall rate from the machine learning literature, but recently I was reviewing a thesis which used the terms correctness and completeness. A quick ...
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2answers
648 views

Comparing two histograms

I would like to know what are the common techniques to compare two histograms? I have histogram of two images and I want to see are they similar or not meaning that is there any correlation between ...
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0answers
175 views

Machine Learning Process for detecting edges of overlapping objects with OpenCV

I'm quite new to machine learning and a bit unsure about the whole process and the interpretation of the results. The Task: I have images with some objects of somewhat the same color and shape which ...
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3answers
44 views

Computing Image Similarity based on Color Distribution

Image Similarity based on Color Palette Distribution I am trying to compute similarity between two images based on their color palette distribution, let's say I have two sets of key value pairs as ...
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0answers
32 views

Dimensionality reduction by predominant component analysis

Does anyone know the concept of dimensionality reduction by predominant component analysis? It was introduced in the following scientific paper: Grundland & Dodgson, 2005, The decolorize ...
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1answer
67 views

What do NORB and CIFAR stand for?

The MNIST dataset is a standard benchmark data set of digit images. MNIST stands for 'Mixed National Institute of Standards and Technology'. The NORB dataset is a commonly used dataset of binocular ...
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1answer
36 views

Image clustering and Dirichlet process

I am reading a paper about the Dirichlet process and image segmentation. (http://dl.acm.org/citation.cfm?id=2404806) How is (3) below derived? Do any articles or posts explain image segmentation and ...
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0answers
30 views

Conceptual question on image pattern representation

I have a basic question regarding pattern learning, or pattern representation. Assume I have a complex pattern of this form, could you please provide me with some research directions or concepts that ...
2
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1answer
129 views

Image processing with neural network

I am trying to learn how Neural Network works on image recognition.I am confused that how neural network that how i will give input.My defination is find(track) object in squence of images(particular ...
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1answer
49 views

Help in convolution operation

I am stuck in understanding how the output of convolution operation is obtained. Can somebody please show the steps? The question is an image is processed by applying 3*3 mean filter . What is the ...
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1answer
123 views

What is meant by binary images of handwritten digits?

I can understand what a handwritten digit is, but what is meant by "binary image"? Can someone explain it? I am studying machine learning concepts. In doing so, I've come across many types of inputs. ...
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19 views

Detecting/recognizing landscape and architecture photographs

I have a large set of photos of various kinds, labeled with some tags but the tags cannot really be trusted (e.g., some portraits will have a tag 'portrait' while many won't, likewise for 'landscape', ...
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73 views

Edge Probabilty Using KL-Divergence Code in Python

Its a little complicated question, so please bear with me. I am doing Image Segmentation using Swendsen-Wang method for Image Analysis./ (stat.fsu.edu/~abarbu/papers/jcgs.pdf) I have to calculate ...
2
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1answer
54 views

Having a Neural Network recreate what it's learned

I've created a basic Neural Network that learns from basic information and can verify whether or not a piece of information matches it's parameters from a match percentage. Conceptually however, I ...
2
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0answers
73 views

Emotion recognition lip zone processing

I want to detect emotions by comparing the cropped lip zone with different templates and output an emotion based on the score. So far I've applied: Normalization Discrete and fast Fourier transform ...
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0answers
38 views

Adding errors in quadrature for mean values

I understand that for $ Z = \frac{X}{Y}$, the error in quadrature would be calculated as, $\Delta Z = Z \sqrt{\big( \frac{\Delta X}{X} \big)^2 + \big( \frac{\Delta Y}{Y} \big)^2}$. In my case, X and ...
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3answers
31 views

Ressources for image processing

I want to read, study statistically and modify numerical images. During school i used to work with built in functions in MATLAB. I don't have this possibility anymore. Now i want tout resume my ...
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0answers
12 views

How should I choose SNR value that the object is recognisable by the human eye from background noise?

I have some images that are made of an object and some amount of background noise. I have sampled the object for example at 40%. So the object is becoming pixelated, then I inject some amount of noise ...
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0answers
58 views

Spatial patterns analysis for images

i have done some research about spatial patterns analysis, using some spatial statistics mesures, all the cours that i found talks about spatial statistic in the context of GIS, in the context of ...
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0answers
21 views

Pseudoinverse for time series filtering

Suppose I have a few time series, that are strongly correlated to each other, and I consider this to be noisy data. How do I use the pseudoinverse technique from image processing to filter this data?
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1answer
244 views

Normalized cross correlation vs Euclidean distance in template matching

What is the difference between normalized cross-correlation and Euclidean distance in pattern recognition? -- especially if we want to do recognition with template matching. I understand about ...
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1answer
27 views

Distance Transform In Image?

I understand how to compute Distance Transform for BW image In BW image we can calculate the distance of the pixel with non zero pixel value using Eucledian Distance. But I dont undertand how to ...
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0answers
13 views

EnergyThe meaning of these term in Image Processing?

Im newbie in Image Processing field, and I got many term that wierd. There are : Moments Local and global characteristic Energy of Image Color Temperature What each of them represent in Image??
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0answers
30 views

Detecting noisy patterns in document images

I am looking for features to extract to distinguish between text objects and arbitrary noisy patterns in degraded document images. This is an example of a document with some parts of noise, I have ...
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0answers
20 views

Metric to show the overall similarity between two set of points obtained from handwritten word?

In my case, I would like to compare different handwriting to a template handwritten word, and return a single metric to show how closely the input matches the template's shape. The lines are the same ...
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3answers
434 views

statistical method for spatial correlation between images

I am working on analyzing a data set and I was wondering what would be the most statistically valid method of demonstrating that there is a strong spatial correlation between images. I have a data ...