Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [image-processing]

This tag is for the mathematics involved in the field of image processing. Many such questions are also appropriate for Signal Processing Stack Exchange.

This tag is for mathematical questions about the field of image processing. Note: programming issues related to image processing belong on other Stack Exchange sites: Stack Overflow, Signal Processing or Computer Science.

649 questions
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How to convert coordinate system of java image to conventional coordinate system?

I am working on some image processing problem. So I am facing a problem that in java the coordinate system of image is not like the conventional coordinate system used in Mathematics (where origin is at bottom left corner), but instead it is a…
Abdul Fatah
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Keeping a constant resolution scale of an image

Intro I'm writing a program that zooms in and out on an image and the only way to do it with the data I have is to change the limits of my graph. The aspect ratio (scale of x to y) always remains 1:1 and the ratio of the x limits to the y limits…
Spaderdabomb
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What is the best iterative scheme to find the solution of a linear minimization problem in image processing?

I have a linear minimization problem as, $$ \inf_u E(u)=‎ \inf_u \frac{\mu}{2} \int_{\Omega}(u-f)^{2}d\Omega+\frac{c}{2}||u||^{2}-\langle u, g \rangle, $$ where $f$ and $g$ are fixed and c is a positive scalar. Since this minimization problem is…
eli
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Finding lines from a set of points (image processing)

I am not sure this is the right place, but it is a math problem too so let me give it a shot. This problem comes from Robotics but can be totally extricated from there. In brief, we have a set of points $(x,y)$ on a plane of specific dimension..…
pitosalas
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Can anyone explain to me what this equation does/ how to read it?

I'm following this paper to create my own version of Poisson image editing. However, I don't quite understand what equation 1 and 2 are asking me. The simplest interpolant $f$ of $f^*$ over $\Omega$ is the membrane interpolant defined as the…
A0sXc950
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What does dynamic range values in SSIM image quality technique refers and how to calculate?

http://en.wikipedia.org/wiki/Structural_similarity Below is java implementation of SSIM. package com.ssim; import java.awt.image.BufferedImage; import java.awt.image.Raster; import java.io.File; import java.io.IOException; import…
janak
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Edge detection in images

I'd like to detect a horizontal and vertical edge in images such as this one to form a new coordinate system:enter image description here The desired edges are shown in red. The object shown is a printed circuit board. Because the PCB comes in…
user173729
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What is a continuous image function?

I'm currently studying Zernike Moments, and came across the formula which is: and it is said that $f(x,y)$ is a continuous image function that is mapped (inner product) onto the Zernike basis function $V_{nm}(p,\theta)dxdy$. But I'm not entirely…
Maxxx
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Curve between 0 and 1 for contrast filtering

I was editing an image by increasing the contrast. For this I used the formula $(\tanh(\mathtt{CONTRAST\_FACTOR}*(x-0.5))+1)/2$ This formula has limits at 0 and 1, with y=0.5 at x=0.5. The problem for my situation is that y is only limited between 0…
coolcat007
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Create Fisheye from image

I'm trying to modify a function to create fisheye effect on image (i use a software that permit to modify every single pixel of an image). At the moment i use this function: float kk=width*0.5; float ll=height*0.5; float dx=(x-kk); float…
MatterGoal
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VQMT image blurring metric

I would like to know how the MSU - Video Quality measurement tool: here calculates the blur metric. What could be the mathematical computation to calculate blur? I want to do something similar in my Image pipeline. EDIT: If I have a blurry image, I…
goldenmean
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How to decompose deformation of disc into its components?

I have a disc made of a malleable metal. It goes through some process which arbitrarily deforms it (bend, shrink, stretch, twist etc). The process is a black box to me right now, but I have some clues based on previous knowledge. Is there a way to…
rick_2047
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Why is Non-local means non parametric?

I am working on NL means for denoising and other segmentation based results. I am confused as to why it is called non parametric. It does have parameters which are definite with regards to patch size, window size and few other factors but the…
Sreenivas Murali
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How do I find a number that will scale an image but keep the dimensions whole numbers

I have an image with width 4096 and height 2896. I would like to scale the image to below 4000 pixels wide - and as close to 4000 as possible. I would also like to keep the dimensions whole numbers. Is there an equation to do this? Thanks More…
lindon fox
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Finding Position of an Object in an Image Relative to a Camera

Hopefully I have this in the correct place, but apologies if not. What I'm trying to do is given I know the pixel that I am measuring to, how would I find the x, y and z co-ordinates of that pixel relative to the camera in millimeters, given that I…
Sean Kelly
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