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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Efficient image matching technique for small match library set
Background
A scene captured from video frames from an Android mobile device camera are to be analyzed in real-time. The scene will contain up to 12 distinct photos. The library images to be matched ...
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Set of all images with a certain MSE between themselves and a given image
Mean squared error between two $M\times N$ images, $I[m, n]$ and $D[m, n]$ is defined as:
$$
MSE(I, D) = \frac{1}{M\times N}\displaystyle \sum_{m=1}^{M}\sum_{n=1}^{N}(I[m, n]-D[m, n])^2
$$
For a given ...
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Image Processing Perspective Transform
This youtube video shows the current world record for smb1 speedrun, but it is recorded from a phone on a CRT TV.
https://www.youtube.com/watch?v=IuVLtaB8uQk
Is it possible through perspective ...
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how to change this program from MIMO to SIMO
first of all this my program about Spatial Multiplexing MIMO . I need change this problem from MIMO to SIMO .Is this seem applicable or not? .if applicable how to do this and what the parameters must ...
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Can “Frame Difference Method' be apllied for ”Motion Detection Based Anti-Theft Project"?
I am new with image processing. I will start to a project named "Motion Detection Based Anti-Theft Project" as i said. I have to use MATLAB and STM32F4 microcontroller in this project. I don't want to ...
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1answer
27 views
Why zero padding the 2-d DFT interpolates images in spatial domain?
I was applying different image interpolation techniques and I came know to about interpolation in frequency domain. In this technique we first take 2d DFT of an image, padd it with zeros and take the ...
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1answer
8 views
order or sequence of performing image denoising, image deblur and image super resolution
In the normal workflow of image processing, there are multiple operations, increase image contrast, image denoising, image deblur and image super-resolution. What are the sequence/order of performing ...
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PSNR calculation with float arrays
The PSNR definition provided by wikipedia is often quoted in discussions regarding PSNR and other similarity metrics.
Essentially the PSNR calculation has two components: the mean squared error and ...
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1answer
20 views
Determine the position where an object makes contact with the surface [closed]
I am an absolute beginner with image processing. I would like to determine the spot where an object made contact with the surface. E.g., if I throw a ball on the ground, is it possible to represent ...
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30 views
Finding Homography Matrix Using Lines
I have some Points and Lines from original image and the corresponding points and lines from top view image.
-> I tried to find homography using points
Used OpenCV function findHomography(...
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center of oblique viewed disk with known radius
I also posted this on the math stackExchange, but it also fits to this forum, so I hope it's fine to post it here as well.
I'm working on an issue related to image processing that I simply cannot ...
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Approaches to Segmentation in images of water surface
this is my first question here. Therefore please help me inform me when I miss any good practice in asking questions here.
Given a short video sequence of an water surface, I would like to detect if ...
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1answer
30 views
Understanding 2D alignment using least squares
In Computer Vision Algorithms and Applications book by Richard Szeliski, the author explains 2D alignment using least squares as follows:
Given a set of matched feature points ${(x_i, x_i')}$ and a ...
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1answer
36 views
Localized Gamma Correction
Question:
Is there an algorithm that does (what I would call) "localized" gamma correction?
That is, applying different gamma corrections on different parts of an image, using a masking filter or ...
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What is the different of Maximum Aposteriori Probability (MAP) method and image registration with reconstruction in multi image super resolution?
I am working on multi image super resolution (MISR) for thermal imaging. I have read several papers and slide about it but there are some confussions.
First, I know that the basic of MISR is combining ...
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Measures of edge image continuity and connectivity
Suppose I have a scalar image $I:\mathbb{Z}_{1,m} \times \mathbb{Z}_{1,n}\rightarrow [0,1]\subset \mathbb{R}$, where $\mathbb{Z}_{1,m} = \{1,\ldots, m\}$.
(For instance, computed as the (scaled) ...
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Deriving transformation from input and output images
I will preface this by saying that my undergrad signal processing course is very far back...
Context:
I am comparing images of global illumination (GI) passes. I want to be able to change the ...
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1answer
35 views
Non Circulant Translation Using Fourier Transform
The translation property of Fourier Transform (FT) for a two dimensional image $f$ is as
$$
f(x-x_0, y - y_0) = F(u, v)e^{-j2\pi(ux_0/M+vy_0/N)}
$$
Using this equation, the following code (in Matlab) ...
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Remove specular highlights from a grayscale image
What methods are there for removing specular highlights from an image without using a threshold? I need to remove highlights from microscope images of droplets in order to recover their approximate ...
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2answers
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Restore RGB Values from Luminance Value?
I am not sure, but can we get RGB (Red-Green-Blue) values from calculated luminance value for each pixel?
...
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3answers
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Can the colors of an image be interpreted as “virtual” Doppler effect? [closed]
In astronomy, the Doppler effect is used to estimate approximate distances to stars and other celestial bodies.
Using the same principle, lets say we divide an image (photograph) in pixels and that ...
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2answers
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How would you interpret the pattern in this picture? (generated by re-sorting pixels based on their RGB value)
Was playing with some pictures and ran the ruby code below. The code reads an input image using the ImageMagick library, gets an array of pixels, re-sorts the pixels and then writes out an image with ...
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1answer
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Which Noise Reduction Algorithms Are Used in Commercial RAW Image Processors?
I'm trying to guess what noise reduction algorithms are used in commercial processors for raw images from digital cameras. I find this fairly easy to do for the sharpening algorithms (most use unsharp ...
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1answer
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What Is the Correct Way to Apply Richarson Lucy Deconvolution to Luminance Data?
My question concerns the Richardson–Lucy deconvolution algorithm, which is described in Richardson's original paper. I am interested in applying it in the context of a raw image converter for digital ...
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3answers
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Reduce the number of intensity levels of a grayscale image in Matlab
I have written a Matlab script to reduce the number of intensity levels of each pixel of a grayscale image from 256 to some power of 2.
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37 views
Implementing rotation in frequency domain and map it back to spatial domain
Please consider the following small example:
...
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25 views
Fast and Slow motion video detection using Optical Flow
I'm trying to calculate a "video motion" value in a given video sequence, meaning how fast or slow motion the video is. For instance, if a video is about a car racing, the value is high. Whereas if ...
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What are the Red-Black Wavelets transformation for color (RGB) images?
I am looking for Red-Black Wavelet transform implementation on internet but I am unable to find it. Or How wavelets can be used for Images. Please help if you know how wavelets can be used for images.
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How to make ground-truth image for document image binarization task?
The two images are from DIBCO (Document Image Binarization Contest). The objective is to find a solution to binarize the top image (original image) to be similar to the bottom one (ground-truth image)....
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3answers
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Calculating the numerical gradient of a volume in one direction at a time
I want to calculate the gradient of an image volume in one direction at a time.
Using the built-in function of Matlab gradient() I can get the ...
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0answers
19 views
Image processing and object detection in sales force automation
We have a specific requirement in our sales force automation product.
Requirement in merchandising module
There is one shelf check activity in merchandising where salesman is capturing which ...
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2answers
56 views
Digital Image Processing Textbook with Specific Topics
I am looking for a Digital Image Processing and analysis textbook, but there are specific topics that I would like the book to cover. Among other topics, I would like it to include a discussion of:
(...
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1answer
63 views
What is meant by product of two images?
I would like to compute the product of two images. I tried with the code below. But the result is not like I expected. Can you tell me where is the problem in my code?
https://ibb.co/Njc8w3b
...
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1answer
147 views
How to remove striped noise from this image. Which filter or algorithm use better?
I need to process a gray scale image. The task is to remove the stripes, which constitute some noise.
I have next origin image:
This image received many channels ADC(Y) in moment of time (Xn) from ...
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Logical Steps to segmenting Lung Fissure Structures
I am given the task to do the Lung Major Fissure Segmentation in a CT image to find it's position in an image.
This is what a Major Fissue looks like: https://www.med-ed.virginia.edu/courses/rad/cxr/...
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1answer
38 views
2D Multi-scale dot enhancement filter based on Gaussian filter and Hessian matrix
I'm trying to implement an algorithm that enhance dot and line like structures based on Hessian matrix, the algorithm uses Gaussian filter with different scales before calculating the hessian matrix ...
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1answer
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morphological processing : Hit or Miss shape detection
I am currently looking at shape detection for Hit or Miss. I am having a bit of trouble with the concept of the window that they have you to detect the shape. Up till now reading about hit or miss ...
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need tool to identify most focussed image in a series
I have a situation where I am sent a series of photographs of hand-written documents (quite old, from 1850-s). Each photo is done just as you and I would photo a page from a book, so not a ...
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2answers
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Transforming RGB images including NIR to LAB
I'm relatively new to image processing, so I hope I don't ask trivial questions.
I have some images that I want to use in a machine learning context. The images have four color channels: RGB and NIR (...
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1answer
41 views
What is the point spread function and optical transfer function and what uses are they in image processing
So I seem to really be struggling with the concepts of the point spread function (PSF) and optical transfer function (OTF) and what they are used for in image processing.
Everything I seem to google ...
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1answer
30 views
Develop a simple image classification system by using Laplacian of Gaussian (LoG)
I am tring to write a simple CAD system to classify some images within two groups by using Laplacian of Gaussian (LoG). I am using scikit-image for this tasks and I want to use DNN in keras to train a ...
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Thermal image based segmentation [duplicate]
I'm working on a project to do segmentation of thermal images. So far, the methods have produced limited segmentation performance (k-means, Otsu's Method, Sobel, Canny, LoG).
I am trying to achieve ...
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BRIEF feature vector random point sampling 3rd method
When using the BRIEF algorithm to generate a feature vector, 5 methods are provided for selecting 2 random points inside a feature point patch. The 3rd method is described as follows:
Let consider ...
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1answer
22 views
How to partition collagen into separate fibers?
I have a picture representing collagen fibers of a tissue:
Image is binary consisting of a background (pixels with value 0) and white collagen (pixels with value 1). A zoomed in section of an image ...
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0answers
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Removing striped noise from an image
I was just wondering if anyone could explain to me the approach one would take to removing striped noise from the fourier domain of an image. I was reading an article about MRI image from 1 just ...
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1answer
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Gender classification using Periocular Region [closed]
I have a dataset of the periocular region, I have images of the male and female periocular region but they are only labeled as left and right periocular region, Folder is a mixture of male and female ...
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Size filtering on binary images
I have noisy images from which I extract the contours using OpencCV's findCountours, which performs binarization internally. This results in innumerable small ...
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1answer
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What is the difference between positive matrix coefficients and negative matrix coefficients of an audio?
I have turned an audio file into an one dimensional array by using audioread function in matlab and found several positive and negative fractional coefficient values.What is the basic difference of ...
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1answer
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How can I detect the tree rings?
I'm looking for the way to detect the tree rings automatically in the wood dist image.
Using the matlab, I have removed the background, and binarized the image.
How can I detect the white and black ...
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Questions about Optical Flow implementations
I have some doubts related to some of the optical flow implementations.
How to compute angular error for optical flow algorithms? I know the formula for computing,
$\theta=\arccos(\vec{v}_c\cdot\vec{...
