Questions tagged [image-processing]
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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what is the kernel ker in the ImageCorrelate of Mathematica Program? [closed]
Thank you for consideration. In image Processing with Mathematica Program, it is an order to ImageCorrelate for an image. In this order there is a "kernel ker", I don't know what is that exactly?
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Locate No Signal Area Between 2 Signals
I have many datasets which all looks roughly like this:
All the datasets have this in common. First there is an artifact around 0 with an unknown (but likely very high) intensity. Then there is some ...
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convolve to differentiate black and white colors
a figure for instance of size 500*500 has half above part with black and below half white should result in a white line where the
white meets the black (something like a single line at line 250 with ...
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Watermark insertion process in image
I'm new in the field of image processing and I'am trying to implement a watermarking algorithm (for medical images in DICOM format) based on this paper.
As written in the paper, this algorithm is ...
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Median filter problems about the output image
An image has an isolated cluster of dark pixels on a light background. The area of the cluster
is $(n - 1)/2$ pixels where $n$ is an odd positive integer. What happens to the cluster when it is ...
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How to calculate the output image with the following kernel?
What is the advantage of using this equation? I guess we may use Taylor series, but I tried my best and could not get the equation.
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Using Local Binary Pattern for finding Homography between two Image
Can LBP be used to find the homography between two images with similar field of view for Image Registration?
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Image Processing: 360x180 panorama from discrete images
I'm coming from math as I was told that this would be a more fitting place for this question.
For the last few weeks, I have been trying to create a full 360°x180° spherical panorama from distinct ...
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Gaussian Mixture Model-UBM based for image recognition
Scenario:
Open set recognition: Unknown individuals may appear on scene (CCTV).
Gallery = 10 individuals with a mug-shot image per individual.
Approach:
Gaussian Mixture Model-UBM based
Use video ...
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Magnification of a colored image through two color space: RGB & YCbCr
I have tried to magnify a colored image using bicubic method. I did this in two ways; First, I resize R, G, and B parts of it. Second, I transformed RGB to YCbCr color space and then resized Y, Cb, ...
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Integrating over an image?
I am currently trying to implement the method described in this paper. In short we have a system of the form $a=B\times c$. Where
$$a_i = \int d^3r \space w(r)f_i(r)t(r)\quad\text{and}\quad B_{ij} = ...
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What is a good algorithm, and framework, to calculate centres of gravity or mass (cog)? [closed]
I'd like to take an photograph, subdivide it into a tesselation, either of squares, or (ideally), hexagons, and then find the centre of gravity (or, if you prefer, centre of mass) of each cell of the ...
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Line Detection with OpenCV
I'm trying to use the native functions of OpenCV HoughLines and HoughLinesP to detect the lines from an image. The Canny edge output of that image is the folllowing:
The problem is that the OpenCV ...
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Extrinsic Camera Parameters without introducing control points?
I am new to the field of Camera Calibration. We have successfully calibrated our camera through classic method (using checkerboard etc).
I recently realized there is a field of research for Automatic ...
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Wiener filter with no WSS process
I'm trying to learn something more about Wiener Filters and I can't find anywhere what happens when I feed a Wiener Filter with a non WSS process. Could anyone give me an explanation or any book (...
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Good book for MATLAB image processing functions explanation [closed]
What are some books that can explain what is actually going on in the MATLAB functions for image processing? Some examples would be the function im2bw, ...
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Measure similarity between quantized grayscale images
I want to measure the similarity between quantized grayscale images (8 levels) that mostly depict organic patterns found in nature, say pigmentation patterns in animals (zebra pattern, leopard spots,.....
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Anti tremor motion detection
I'm programming in c# using opencv (emguCV). I use motion detection approach to detect some changes in a paper wall. For example it's may be colored by a laser pointer. My problem is that when I use ...
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Target detection for UAV landing
I would like to detect and track the following target to land an UAV. Target size is $1\rm m \times 1\rm m$.
I have tried SIFT + FLANN but there is too few keypoints to have a good match.
Have you ...
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What is an 'Oriented' Band-pass Filter?
In this research paper, Section 4.1 talks about a filter called "Oriented Band-pass Filter".
What does it actually mean by 'Orientation'?
Also, the article gives a function,
$$H(u, v) = \frac{1}{1 +...
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Is there a way to detect ambiguous edges?
I'm writing a program that can detect veins(the dark lines) on an arm.
When looking at the image at full size, you can easily make out where they are.
But when zoomed in around a vein I get ...
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How to use Mikolajczyk evaluation for detectors/descriptors?
I want to compare different detectors/descriptors (both binaries and not) for my application and I want to use the Mikolajczyk evaluation framework, which is became a standard in the community about ...
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How to calculate to structure tensor?
Structure Tensor is a matrix in form:
$S=\begin{pmatrix} W \ast I_x^2 & W \ast (I_xI_y)\\ W \ast (I_xI_y) & W \ast I_y^2 \end{pmatrix}$
where $W$ is a smoothing kernel (e.g a Gaussian kernel)...
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Analytical expression for salient Blob detection in scale space
I am working on exact mathematical expression which can be obtained in image processing tasks.(I do not know much about image processing but my work is more mathmatical) In Gaussian scale space, we ...
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processing photo diode array data
We have designed a system which has an 8X8 array of photo diodes, we sense 10ns pulses of laser falling on those photo diodes with a repetetion rate of maximum 50Khz i.e. 20us, we were successfully ...
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How to classify images based on the amount of colors in the image?
I have a problem where all images have the same object; however, these objects can either have number_of_colors<=3 OR number_of_colors>3 and images are not labeled.
My attempt starts by ...
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How to specify 2-D coordinates of an object in matlab?
This is the scenario: I marked two axes (figure below) on a board and a camera(global vision system) sees the board. I want to make the vision system to recognize $X$ and $Y$ axes and specify ...
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Pearson correlation of neural responses with it's linear estimation
I am trying to understand the following fact from this article (page 13):
How can single neurons predict behaviour
Suppose I have a linear estimation of a stimulus:
$ \hat{s} = \mathbf{w}^T(\mathbf{r}...
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How can a medical doctor use the information given by someone working in medical image computing(shape analysis)? Details follow
Posted also here, where it's been put on hold. I did modify it afterwards though.
https://biology.stackexchange.com/questions/43997/how-can-a-medical-doctor-use-the-information-given-by-someone-...
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How to approach detection of anomalies in a video feed?
As part of a project I have a video from a quadrotor that captures the road and the environment around it and I want to identify and detect potholes and speedbumps on the road using image processing. ...
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Hand Jitter Problem
I am currently developing algorithm using openCV C++ for implementing laser as a mouse.Currently am having an issue of hand jitters.(ie. The presenter's hand may shake unnecessarily which may cause ...
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Proximal operator of image Laplacian
Let $\alpha, \beta > 0$ and $\Delta := \nabla^T \nabla$ be the discrete laplacian operator,
$$\nabla: \mathbb{R}^{n_x \times n_y \times n_z} \rightarrow \mathbb{R}^{3 \times n_x \times n_y \times ...
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How can I improvise matlab code from GLCM to CLCM(Color Level Co occurrence Matrix) for feature extraction in texture analysis?
Currently I am doing my project on SKIN DISEASE DIAGNOSIS USING TEXTURE ANALYSIS in IMAGE PROCESSING domain.In this project,the histopathological image of diseased skin image is given as input and the ...
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Algorithm to extract polygones with holes [closed]
I have this picture and would like to extract the bones.
First I thought of contour-Tracking, but as you can see in some bones there are holes (Like for example at the left finger, in the bone in the ...
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What does 'correlation' and 'de-correlation' mean in image-processing?
Here are some problems:
Does it mean these is some relationship among neighboring pixels?
I've read about DCT has a property of de-correlation, I have a doubt whether it means DCT neighbor ...
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How is the luminance vector calculated for these linear matrix transforms
In the article "Matrix Operations for Image Processing" by Paul Haeberli there is an example described using a matrix to alter the saturation of an image. In the example given the author first ...
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Acoustic characteristics of thoracic diaphragm
I am looking for any kind of information about the acoustic characteristics of the thoracic diaphragm. In particular, I'm looking for characteristics which will allow to differentiate it from other ...
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Why correlation coefficient template matching perfoms better than cross-correlation and square-differences method
I am using this template in OpenCv's match template function by converting all images to grayscale.
Here are my result using sum of square differences,cross correlation and correlation coefficient....
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Creating a convolution kernel from filter description
I am not quite sure whether the question I am stating is right, or if I am trying to combine two not related topics but here it comes..
I am trying implement and apply a contra harmonic mean filter, ...
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Find tracing/plotting stacked bands/lines in an image
I have images with lines/bands, the bands/lines are parallel but can be of different gray levels, I want to extract or trace the lines/bands as single line, all lines/bands are parallel.
Source:
...
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How to efficiently calculate points of intersection of a straight line and a contour?
Ex.
I have an image, let's say 100x100 pixels with some shape on it. And a set of straight lines that are passing through origin located at some point of image, for example origin located at point (...
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Segmenting simple objects without shadows
I am trying to segment very simple objects like boxes and bottles. I am using GrabCut and it works extremely well when there are no shadows or when the shadows are soft - but as soon as there is a ...
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How to get an objects dimensions from video
I want to be able to measure an object using the camera on my phone. How would I go about getting an objects width and height from a video? My first thought was some type of 3D tracking of the video. ...
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Comparing the spatial frequency between groups of images
I have 2 groups of images, and I want to compare these groups based on the spatial frequencies of the images.
In the end, I'd like to be able to say "group A is/is not significantly different from ...
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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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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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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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what is the difference among noise,blurring and contrast? [closed]
I want to know the following
what is the difference among noise,blurring and contrast ?
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Are there any other libraries for Image Processing using hadoop?
I have been looking for libraries for Image Processing using hadoop, but by now, only have been able to know about hipi, and to some extent hadoopy. Are there any other libraries for the same?
Hipi ...
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pre-processing to improve feature detector before tracking
I am trying to make tracking for soccer player, I need to detect features from this player and then estimate the distance difference of these pixels over number of frames.
first I have to detect the ...
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