This tag covers signal processing where input is an image, such as a photograph or video frame and the output could be an improved or altered image, parameters related to the image or information about features within the image.

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9 views

what is the difference among noise,blurring and contrast?

I want to know the following what is the difference among noise,blurring and contrast ?
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6 views

How to solve the problem in octave :“GraphicsMagick limits images to 8 bits per pixel ”

Could you please help me to solve this problem, when I run GNU Octave and try to use the command imread() to read an image, I get the following warning: ...
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15 views

Transformation validation

I am am trying to see the validity of my geometric transformation, by imposing a point i got from a tracker in the original image and superimposing it on the image after the transformations. The ...
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1answer
18 views

What's the best way to compare the same object from different “crops” or angles within multiple images?

I read a similar question, but I'm not sure the techniques discussed will help me. Take for example the two following images: I'm trying to determine if the above images are sourced from the ...
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2answers
145 views

relation between luminance and eigen values of an image

There are some research papers in the literature which apply Singular Value Decomposition (SVD) on an image to decompose the image matrix into U, ...
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0answers
19 views

What is difference noise reduction technic on additive gaussian noise and poisson noise?

As I know the camera noise are consisting like poisson noise and additive gausian noise. I want to know about What is difference noise reduction technic on additive gaussian noise and poisson noise? ...
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1answer
27 views

what is the difference between HSV and CIE-Lab color space? [closed]

when do we use HSV color space and when do we use CIE-Lab color space?
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44 views

Cannot see effect of modifying eigen values in Python (SciPy, NumPy)

I am doing some experiment for increasing the intensity of low exposure image by changing (increasing) the eigen values. In Matlab I apply Singular Value Decomposition on the image matrix to get ...
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1answer
82 views

What does zero-mean noise mean?

I don't know where to start from. and this question might be very silly, I have found such as comment from someone at here, "I think if you noise is zero-mean it doesn't matter, if not it does (you ...
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1answer
33 views

Identification of a given barcode as either 1 D or 2 D

I am working on an algorithm (in MATLAB) to identify/classify a given bar code (image) as 1 D or 2 D. I have considered using the contrast of THE IMAGE matrix as a parameter or using the FFT of the ...
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0answers
7 views

significance of real valued coefficient and complex valued coefficient

What is the significanceof real valued coefficient and complex valued coefficient with respect to DCT and DFT.And how does it effect signal processing?
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1answer
113 views

How to learn image processing / computer vision in a practical way?

I am new to the field of image processing / computer vision and I find it very hard to get my hands on the subject. I read a lot about the basics/theory but I feel in no way able to use this knowledge ...
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15 views

Is affine the right transformation for coordinates change

Ill begin by describing my problem: i have a video, which was used in a tracking program. In that program the object being tracked receives per frame X,Y coordinates which are not the same as in the ...
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13 views

How to combine SURF and Harris points

As we know at Matlab, there is function to detect Harris or SURF feature individually. Then I need to combine these two list of features from both the Harris and SURF to make the matching more ...
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13 views

How to calculate Coherent Change Detection?

I have two images which I wish to compare the difference between using coherent change detection and I'm having some trouble figuring out how to apply these signal processing equations to my data in a ...
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0answers
33 views

Get problem to understand “Topological Structural Analysis of Digitized Binary Images by Border Following” Suzuki Abe

I'm confuse with their explanation about definition 1 notation of 4- (8-) and 8- (4-) in Suzuki Abe paper "Topological Structural Analysis of Digitized Binary Images by Border Following" pg 34, and ...
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0answers
23 views

How to understand the mathematical notion of a image?

An analog image is a 2D function $$ f \in L^2 ([0, 1]^2 )$$ where the unit square $[0, 1]^2$ is the image domain. (Gabriel Peyré Advanced Signal, Image and Surface Processing, chapter 1) How to ...
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0answers
28 views

Satellite image quality assessment

I have satellite image and after I processed it, it became better than the original, how can I prove that it is better such that the psnr and mse give me low quality as it is different than the ...
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1answer
33 views

how to add two images in one, next to each other

I have two splited images from diference matlab files. Now i need to merge them, near to each other. I tried supblot, imadd,cat methods, but nothing works. Please help me. rezult after sublot ...
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25 views

Need Help how to remove unwanted edge detection

Hye everyone. Really need help. How to remove the branch that i circle in the image. What parameters i should use. Really appreciate your help.
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20 views

How to preprocess fmri image with FSL?

I need to preprocess fMRI images with FSL (motion correction etc.). I never used FSL before and never done preprocessing. Is there a good tutorial which describes step by step how I can do the ...
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0answers
18 views

How to implement extended structure tensor

I am implementing an extended structure tensor that defined as where (*) is convolution operator; K_sigma is a Gaussian kernel with standard deviation sigma. The subscripts x and y denote the ...
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1answer
27 views

Image region-based representation

I have a homogeneity image that includes two regions $\Omega_1$ and $\Omega_2$. How to represent the image by decomposition of two regions? For example, the famous way is representing by the mean ...
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0answers
21 views

What does visual clue means ?

Given a keypoint p detected in an image I . What does visual clueof the keypoint p mean ? ...
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1answer
58 views

How to estimate the noise of an image?

I want to know how to estimate the noise of an image? Also is this represent the camera's noise? Does anyone know how to estimate the noise of an image or camera? Update: Especially, I want to ...
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0answers
16 views

How to represent the relationship of pixels within a cluster

I have a question about image processing that need your help. I have an image I that includes foreground (FG) and background (BG) regions. I want to represent the relationship of pixels within these ...
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25 views

Finger Detection on various backgrounds

I tried tracking down the finger placed in the frame. Constraints: Algorithm works in live streaming of USB Camera, so there will be a lot of background changes. Algorithms tried: Tried ...
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5answers
258 views

Noise Removal from an image using Opencv

I tried removing noise from the image shown below using Median Blur in OpenCV. But i'm not able to remove the colour noise completely as it is done in Neat Image. Any suggestions.? 1. Original Input ...
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2answers
31 views

What is meant by isotropic diffusion? [closed]

I am working on diffusion of medical images, and I have come across the term isotropic diffusion. Can anyone explain it for me?
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1answer
41 views

How to Linearise an Input Image before applying Color Correction?

I'm doing color correction on Raw images taken from Camera directly. I want to make my Camera reproduce same colors as my Target camera. Here are the steps I'm following: Take Target Color values ...
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13 views

How to compute Homography between two images whose Camera Pose is known?

I want to compute Homography Matrix between two images whose Camera Pose is known, because it is not very stable to compute Homography Matrix from 2D correspondence. I only found camera Pose from ...
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0answers
50 views

Initialization of population for genetic algorithm in matlab

I randomly generated initial 10 population(let each of size n) of genetic algorithm as follows ...
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1answer
26 views

Comparing Images by Defining a Reference Model

I have a microscopy system which periodically captures an image to be used for shading correction. Because these images are captured on tissue slides containing, well, tissue, as well as possibly ...
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3answers
49 views

what are frequencies in a digital image? [duplicate]

I don't completely understand the term " frequency" with respect to digital image processing. for 1D electrical signals , its pretty easy to understand , visually too. higher the frequency - more ...
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0answers
21 views

strange occasional periodic pattern in phase correlation output

I am working on a pattern recognition algorithm where a template is to be searched in a query image (Standard phase correlation stuff). However, in my correlation output I get some strange periodic ...
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2answers
41 views

Good inhomogenity measures in images?

Can you advise me on good inhomogenity measurements in an image? I am trying to find the borders where homogenous zones touch inhomogenous ones in a image. I am going to work with sick lung ct ...
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0answers
24 views

Fit a plane on a 2d picture

My supervisor gave me the hint, to fit a plane on a 2 dimensional image and substract it from it before doing the fast fourier transformation to reduce low frequencies. I get the low frequencies ...
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1answer
133 views

How to calculate the luminance of an image?

Is there any method for calculating luminance of an image? As from wiki got to know Luminance is an amount of energy perceived by the observer and LUX is different from brightness. But still is ...
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0answers
17 views

Coherence of specific area of an image

I have to detect an object in an image. The manner that I am using gives me a number of possible areas of the image that may contain the object. I want to check which is the most coherence area of ...
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1answer
51 views

How to find out whether guassian or salt& pepper noise present in an image, Is there any algorithm

Is there any algorithm for identifying the noise in an image I have to identify whether the noise present in a mammogram image is guassian or salt& pepper.
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1answer
27 views

How matching pusuit algorithm works

I could infer from books and wiki that a matching pursuit finds signal approximations from a redundant dictionary. Let f be the signal, ai be the basis and Ri be the residue.. here we choose the inner ...
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1answer
23 views

Dark image separation

So I have an image. I take it into HSV format and v has its intensity values. now the intensity values of v vary from ...
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3answers
157 views

What is the type of noise in this image?

what reason could make the noise/effect in this image? Below is the original Thanks!
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1answer
46 views

Can a digital image be considered as a tensor ? or have a tensor like structure?

I am wondering if one can assume that a digital image has a tensor structure. I mean for example when we talk about isotropy in image processing, we are talking about the intensity arranged in a ...
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2answers
87 views

Transformation of coordinate set

I have a problem in which i have a video that was taken from the side of the subject, something like this and i need to transform the coordinates of the subject to be as if the photo was taken from ...
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1answer
38 views

Fast Fourier Transformation using parallel processing coding for image processing [closed]

I'm now working in parallel precessing -and i want a full code for fast Fourier transform(FFT) written parallel processing Code for any image processing application
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1answer
46 views

Medical Image quality assessment

How to objectively assess the quality of a medical image(CT,PET,MRI)? What factors should be considered?
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1answer
61 views

homography matrix problem

i have mini project to do about homography , but i am really a beginner in matlab . i have calculated the homography matrix easily by taking a set pixels from both images but the problem is how to ...
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3answers
71 views

Upscaling detection approach

I'm trying to implement a solution that would, to some extent, evaluate a picture telling what are the chances that it was upscaled from the smaller image. My approach is as follows: Take a picture ...
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1answer
113 views

What preprocessing technique can help me to filter the background text noises using matlab…the image is shown below?

Can anyone help me to improve the degradation of the following image....i am working on OCR system in Amharic language and what is the best image filtering technique that can help me to separate ...