In general, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame.

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Which anatomical model to use as “ground truth” for validating an MRI segmentation method?

I am research in brain segmentation task that classify a brain in to 3 classes : White Matter, Gray Matter and CSF. To validate my method, I used Dice Coefficient that compare my result and ground ...
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10 views

Getting image intersection area perentage

i have two flying robot. And they are flying at same height (nearly) and they are looking same direction and pose. Both of them have same camera and the cameras looking to floor. When the robots are ...
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27 views

How to use wavelet decomposition for feature extraction (of fMRI images)?

I have a dataset consisting of fMRI images (from mice) which are divided into 4 groups (different drug dose levels applied). Each fMRI image is 4D, that means each voxel is a time series. For each ...
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1answer
28 views

Invariances in Neural Networks

I have a question about invariances in neural networks. In general, neural nets with enough layers can learn arbitrarily complicated nonlinear functions. Therefore, it's not hard to understand how ...
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0answers
18 views

Correlation of an image in the Fourier Domain

I have been reading up on correlation in the frequency domain, and I just had two questions which I could not find in the book I was reading nor online: [1] So correlation is the same as a normalized ...
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0answers
11 views

Matlab fspecial disk: Algorithm reference or algorithm logic

I'm trying to figure out how the fspecial function works to create a discrete disk in Matlab. This function is an averaging filter that arises in an image processing environment. The Matlab algorithm ...
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37 views

Translation invariance in max-pooling and cascading with convolutional layer

I am reading through this page about convolutional neural networks and I am confused about the part about max-pooling (downsampling a signal/image with the maximum value in a block). Apparently, one ...
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0answers
4 views

Is the same to calculate the Moments of an image using only its vertex?

The below image is a convex filled polygon, to calculate its moments we can resort to the Hu Moments and if the image is very big, this could be an expensive process. But if we use only the vertex can ...
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37 views

How to detect those areas which are lightened up

I have two images of a scene, IA and IF (this is not no-flash and flash image case). They can be thought of as two binary masks. Image IA: Image IF: If you observe closely, there is a change ...
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5 views

How can you test Gamma in ISP for test?

In CMOS image sensor, there are gamma processing block in the so many ISP chains. Is there any one know how to test the gamma block only whether working good or something wrong? How can you test ? Is ...
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1answer
47 views

Estimating an image filter from examples

I am sure this question must be fairly easy and could have been answered on this site but perhaps I am not finding the right keywords to search for it. I would like to know what are the common ...
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3answers
79 views

why the ultasound image is noisy by speckle noise?

My first question : I want to know why an image is noisy ?. why the ultrasound, SAR and Laser... images are noisy by a multiplicative noise not an additive noise? Another question : So the ...
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19 views

Remove noise from Binary image, License Plate noise removal (MATLAB)

How can I remove noise form Binary license plate? example images: http://s1.upload7.ir/downloads/XB6RfCQnJz5dyJgXPrg2Co5OmAFSkmO8/Untitled.png source file : ...
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1answer
82 views

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 ...
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0answers
11 views

Where can I find images corrupted by periodic/coherent noise?

I found one here https://scipy-lectures.github.io/_images/moonlanding.png I would be more interested in photographs which are naturally corrupted by such noise. I am seeking them in order to use ...
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2answers
35 views

How to find the actual size of an existing object from the pixels of an image?

I am quite new to vision and OpenCV, so forgive me if this is a stupid question but I have got really confused. My aim is to detect an object in an image and estimate its actual size. Assume for now ...
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0answers
15 views

Use the line function commend matlab of PDE toolbox in image processing

I want to use the line new command of PDE toolbox as Matlab R2015a to restore a noisy image with gaussian noise. The PDE is : \begin{eqnarray} \nabla.(\frac{ \nabla u}{\sqrt{1+|\nabla u|^2}}) ...
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0answers
20 views

Can Log Gabor Filters be used on an edge detected image

i'm doing a project on log gabor filters, can i use log gabor filter on an edge detected image for feature extraction,and use these features for classification by ANN
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1answer
41 views

Where is Fourier Transform useful in Image Processing?

I am aware of its use for correlation, and high/low pass filtering. Apart from these is there any case where modifying the image in the Frequency domain enhaces/restores the image ? Is there any kind ...
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32 views

Image Subtraction using Pre-bayer data (.pgm)

Not sure if this is the best stack exchange but I'll give it a shot. I am performing background subtraction to collect Electroluminescent emission (i.e image w/ emission - image w/o emission = ...
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21 views

phase shift between two images (matrices)

I'm trying to find the phase shift between two 100x100 matrices, s and p. To start with I'm using two sine waves (2D) slightly shifted. I manage to compute the correct amplitude spectrum (using the ...
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1answer
13 views

Does bilateral filter exhibit some special properties that can be used to test for the correctness of an implementation?

For this may be a X-Y question, I'm providing the full background story: I'm trying to test for the correctness for a fixed point implementation of bilateral filter written in C. My current approach ...
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1answer
20 views

why always structured Images are considered as 2D signals?

I am dealing with 2D signals that are random. To be more specific my input is a matrix of 1's and 0's. Moreover, at any position (n1,n2) the probability of having a 1 or a 0 is same. One example is ...
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8 views

how to express a separable 2D convolution using properties like commutativity, associativity, etc?

I have two 2D sequence $x(n_1,n_2)=f(n_1)g(n_2)$ and $y(n_1,n_2)$. How can I express this convolution \begin{equation} x(n_1,n_2)*y(n_1,n_2)=(f(n_1)g(n_2))*y(n_1,n_2)=(f(n_1)*y(n_1,n_2))*(g(n_2)) ...
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2answers
37 views

noise remains after applying median filter

So I'm apply the median filter to an image, but at the output, there's blue semi-dots appearing. What are they? This is the output And the python code for anyone interested ...
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15 views

Image Registration

I am trying to register two images of daily objects from different viewpoints (5 to 20 degrees angle). I have been reading about image registration and I feel like the best way to go is using ...
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16 views

Isolating overlapping image

Using a diffraction grating in front of my smartphone's camera, I can decompose light sources into their spectral components. The problem is that the background is not always dark and there might be ...
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19 views

Normalized Cross Correlation in Frequency Domain Windowing for Object Tracking

I'm implementing a normalized cross correlation algorithm in frequency domain on a DSP for object tracking. I have a search window and a reference window. Both windows are zero padded to accommodate ...
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0answers
12 views

Understand about registration between spatial prior and original image

I am working in level set/active contour method using spatial prior information . The main papers that I am focusing:"Automatic segmentation of neonatal images using convex optimization and coupled ...
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2answers
41 views

Using SURF algorithm to match objects on MATLAB

I am trying to find the difference between two images, using Matlab. The classic built in function that Matlab provides for this is because the two images don't have the same dimensions (The objects ...
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1answer
27 views

Difference between 2D-DFT's and 1D-DFT's of linearized matrices

I have recently left the safe and easy MATLAB environment and begun to use CUDA-C/C++ for image processing. Since CUDA doesn't allow 2D arrays to be passed into kernels I am now used to linearizing ...
3
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1answer
71 views

denoise image MATLAB/Octave Gaussian noise

I want to remove a noise for an image using MATLAB, when the observed image is $$f=u+v$$ where $u$ is the restored image (is the image i want recovered) and $v$ is the gaussian noise. To restore ...
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23 views

Understand the assumption of the ideal bright line in this paper

hope I ask my question on the right place. I am a student and my favorit subject is computer vision. I try to understand some apects of the paper "Three-dimensional multi-scale line filter for ...
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9 views

computing the cross spectrum of two-dimensional matrice

I got stuck with the MATLAB syntax trying to compute the cross spectrum of two-dimensional matrices. I suppose that what I need is something like ...
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0answers
31 views

Looking for Open Source Image Processing Library that is equivalent to HIPS

Note -- would appreciate any comments on ho to improve the question -- I did the best I could but it I feel it may still be sup-par. HIPS was/is an excellent image processing software. It was ...
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0answers
29 views

Edge Detection on small images

I just newly join to this community. Recently I work on edge detection that is applied on the attached picture. The objects that I want to detect are the white square images (there are 4 of them). So ...
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0answers
48 views

EM algorithm and Kalman filter

I am new to the subject of Kalman filtering and therefore my question might seem trivial. I see that there is a tight connection between Kalman filter and EM algorithm when one wants to predict 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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1answer
35 views

difference between feature detector and descriptor?

I am new to feature detection and tracking. can anybody please explain in detail the difference between detector and descriptors. which among these are detectors and which are descriptors : Harris, ...
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1answer
22 views

Downsampling and Gaussian filtering in the context of scale space pyramids

In the context of scale space image pyramids using Gaussian filters I noticed that it's common to downsample the image after blurring with $\sigma = 2*\sigma_{init}$ . My question is: What is the ...
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3answers
24 views

Texture-like measures for quantifying density of data in binary images

Consider the following black-and-white image. It depicts a freehand sketch. I wish to characterize the "density" of sketch strokes. For e.g. the hair strokes are densely grouped together. So are ...
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0answers
12 views

Error correction in a video feed

How does one write software to minimize errors? As in, say I'm trying to look for contours in a region of interest. After writing down the program for contour detection, when I test it the contours ...
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2answers
30 views

What is defference between monocular and stereo image?

I read somewhere in SE about stereo and mono videos. Stereo videos are captured by using two cameras with which we are allowed to measure depth accurately. But what about still images? what is ...
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0answers
14 views

1D FFT on rotated image column by column

I am facing a problem: performing 1D FFT on a rotated column by column on a rotated image, described as following: Original Image: Rotated Image: What I have: original image convolution ...
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2answers
158 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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1answer
26 views

Contour based blurring

Suppose I have an image of a cat and a binary mask image corresponding to cat's location as shown I would like to blur the image region surrounding the cat but as a function of distance from the ...
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1answer
26 views

Machine Vision - Infinity Focus effect

I am working on a research project that involves machine vision. The camera we are using implements infinite focus - I have been informed that this can affect the accuracy of computer vision ...
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0answers
7 views

Medical equipment application

Medical equipment application How can i detect color of and Object (Test pad) ? I Found out different options 1. By illuminating test pad with Red, Green and Blue LED separately and taking AD value of ...
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3answers
39 views

Segmenting and labeling chessboards through computer vision

With almost no experience/knowledge in computer vision, I am currently trying to segment and label the separate squares on a chessboard (i.e. a1 ... h8). My goal is to use the information to ...
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0answers
18 views

Histogram normalization for normalizing background changes

I recorded a sequence of depth images using Kinect v2. But the background brightness is not constant. But It keeps changing from dark to light and light to dark (i.e) So I was thinking to use ...