Questions tagged [image-registration]

Image registration is the process of transforming different sets of images to one common coordinate system.

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Understanding performance of Lucas Kanade Iterative Image Registration Technique

I am reading the paper: Lucas, B. D., & Kanade, T. (1981). An iterative image registration technique with an application to stereo vision. I am having some trouble understanding section 4.3 ...
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PATMAX / Flexible ROI for matlab

I just googled for some hours if there is any toolbox / library for MATLAB with which you can realize something similar like PATMAX does for cognex cameras. I want to add flexible ROI for moving ...
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What does “invariant to bias and gain changes” mean?

Reading this paper, about the ECC criterion (which is included in opencv3), In section 3, the following is stated, with regard to the following equation: (4) $\left\|\frac{i_r}{\left\|i_r\right\|} - \...
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47 views

Homography for (small baseline) Stereo Image Registration

If the distance between two stereo cameras (baseline) is much smaller than the distance to the geometry, is it possible to align the resulting two stereo images using a homography?
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Does Mutual information utilize spatial information to calculate image similarity?

To calculate images similarity based on Mutual Information (MI), histogram and join histogram is required. In the literature, there are 2 contradict opinions about MI operation. 1. MI does not utilize ...
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1answer
69 views

Transforming Non-Uniformly Sampled Image onto Rectangular Grid

I have an image and associated latitude and longitude matrices. So I know the latitude and longitude of every pixel. However, due to the camera orientation, the image is skewed and thus the latitude ...
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267 views

Affine Transformation for matching 2D point sets

I have two sets of 18 corresponding 2D points. These coordinates represent the main joint points of a human body, describing the "human pose". I want to decide if these two poses are similar/have the ...
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Obtaining Subpixel Resolution for Video Processing in Python

I am working on a video processing application to calculate distance between two points using opencv Specs : Linear Pixels - 1600. FOV - 100 mm Resolution per pixel using above data : 62 micron ...
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1answer
712 views

Affine transformation without imwarp

I program function to calculate the overlap area between 2 images (which is called fixed and floating) after transformation but it takes much time and it's complex for me to combine more than one ...
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Images similarity measure using j-divergence

I need to reproduce the result of Xu, Xiaocong, et al, 2016 paper . Mutual information code already was done and work fine. can anyone help me to write Jeffrey’s divergence code? because the I use ...
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91 views

Estimating exterior camera parameters by matching lines using least square estimations (Lowe, 1991)

I'm new to computer vision and graphics. I want to estimate exterior camera parameters using non-linear least square estimation as suggested by "Lowe, David G. "Fitting parameterized three-dimensional ...
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1answer
385 views

Finding the four corners of each quadrilateral shapes in an image

I am working on some image processing application using Matlab. The image after segmentation will look (more or less) like the figure below. Now I want to find the four corners of each shape to crop ...
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1answer
191 views

Parallel Processing Gigapixel Images

Parallel programming is often used to accelerate image processing methods (e.g. Eklund et al., 2013); however, there doesn't appear to be the same level of discussion about using parallel processing ...
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445 views

Estimates sub-pixel shift directly in phase region

I try to estimates shift estimation directly in phase region, by following the proposed method in this Sub-pixel Shift Estimation of Image based on the Least Squares Approximation in Phase Region by ...
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Get slopes of integer shift of an image in radians

I tried to reproduce the result from this paper, However I'm stuck at the Section III of the paper which involve integer shift. Two images which their phase correlation $\theta(k_1,k_2)$ was ...
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1answer
321 views

Estimating scaling and translation between two consecutive temporal images

I have two camera images taken from a camera mounted over a vehicle at time $t$ and $t+1$. I need to estimate the scaling and translation in the images in spatial domain itself so that information ...
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How is “Joint class histogram” algorithm deploy using Matlab?

Image registration and image retrieval depend on image similarity measure to find mutual information between 2 images. Using histogram, joint histogram, and joint class histogram we can find the ...
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126 views

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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370 views

How can we combine 2D image with 3D image for the same sense?

We have 3D point cloud data captured by a laser scanner and need to register it with 2D images to get further information. In our case, the 2D image and 3D points are not overlapping and therefore we ...
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557 views

Best way of segmenting veins from arm?

I have done fews researches and found out approach such as multiscale and region growing, that could be used of extracting forearm veins. However, I tried to use frangi filter and Figure 1 is the ...
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Practical advices for applying phase correlation in image registration task

I'm using OpenCV to detect shift between 2 images, here is sample code (based on cv::phaseCorrelate function): ...
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1answer
111 views

Feature matching of images without corners

I am trying to stitch aerial images using feature-based registration. Most image pairs are matched well, such as this: Others are not matched due to lack of common features: As you can see, the ...
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Automatic landmarks on images of hands

Problem statement I am starting a project soon where I need to create a method to automatically create landmarks on a set of images of human hands. I do not have a sample image but the images are ...
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1answer
2k views

How to achieve image straightening as cam scanner does?

Is it possible to achieve image straightening as cam scanner does I mean selecting a non-rectangular region and converting it to a rectangular region as an image. I can only do re sizing and crop of ...
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1answer
368 views

Are there any template matching / optical flow algorithms for large image displacement?

I had some success with feature-based methods for image registration, but these methods are sometimes unsuitable (e.g. images containing repetitive patterns, very low contrast, low texture, no edges/...
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539 views

Is there a difference between Image Alignment and Stereo Rectification for stereo correspondence or matching?

As far as I know, Image alignment just finds the best fit given two images of the same scene. Whereas Image rectification, with regards to stereo vision, warps the images so that the epipolar lines ...
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167 views

Image registration dataset

I am searching for global purpose Dataset to test some image registration algorithm.. May you please give advice? I am looking for color or gray-scale dataset. I prefer it not to be medical or ...
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1answer
567 views

Camera calibration vs. registration

Suppose I have two cameras, c1 and c2 that are securely installed and do not move. What I want is a matrix T, that takes a pixel of an image from camera c1 and calculates the according pixel in an ...
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1answer
224 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 Feature-...
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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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1answer
92 views

mathematical transfer for different camera attributes

Suppose I have two camera shoots(Image1,Image2) for the exactly same scene (each pixel is alignment correctly) but from different cameras and different light conditions. I want to remove this light ...
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2answers
136 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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2answers
536 views

How to transform or distort or skew a rectangular image to fit arbitrary quad

I have a rectangular image which need to transform so the image fits an arbitrary convex quad. Easy? Except I have an important constraint, the features on the original image must maintain their ...
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262 views

Image registration / fusion optimal similarity metrics

I have a theoretical question about optimal similarity metrics for comparing data sets. In reading this linked paper, pp. 488-489 [1], I read the following 2 interesting statements. On page 488: ...
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2answers
151 views

How does 3D Time-of-Flight (TOF) camera work?

This is my first post in this forum! So Point me if anything is not clear! I want to know how TOF camera works? So I've done Google & read some nice explanation about How Phase difference between ...
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How can I go forward with this image processing task?

0 down vote favorite I am totally new to Image processing. I just started my Master thesis in the area of Computer vision and Machine learning. My background is Informatics. Now, my first task is to ...
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2answers
1k views

What exactly do we do in non-rigid registration?

I found many readings on Non rigid registration, also saw some videos but didn't find a clear explanation anywhere. What I understood is the following Rigid ...
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892 views

Image Registration C#

I'm trying to fuse different images of the same scene which each image have a different focus. I've been told that first I have to perform an image registration to the images. Right now, the result ...
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Detecting blades of a wind turbine

I have many close-range images of a single wind turbine blade (taken from different positions, same angle): I need to separate the blade image from background like this: The problem arises in image ...
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1answer
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Base line detection of text lines

I came across various works in the literature of document analysis addressing the problem of detecting base lines in multi-oriented texts. But no amount of search could give me satisfactory answer to ...
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Image Registration and optical flow

Image registration algorithms can be classified into intensity-based and feature-based algorithms, I want to know When and Why should i choose intensity or feature based algorithm? another question ...
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755 views

How to blend images on a spherical surface / cube map

I already have an algorithm for making panoramic image mosaics by image registration and then blending images in the overlap regions. The following image from Wikipedia illustrates several images ...
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1answer
524 views

Normalized cross correlation via FHT - how can I get correlation score?

I'm using the 2D Fast Hartley Transform to do fast correlation of two images in the frequency domain, which is the equivalent of NCC (normalized cross correlation) in the spatial domain. However, ...
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224 views

image correlation without fft

I want to stitch 2 images by crosscorrelation measure, but I don't want to use fft. I tryed this but something seems to be wrong.any suggestions? ...
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Finding symmetric regions/patterns in image

I have a set of images representing the mean curvature of a human back surface. What I want to do is to "scan" the image for points which have similar, reflected "counterparts" in some other part of ...
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899 views

Software to register a 2D image to a 3D volume

I have been searching for software that can handle the task of registering a 2D image to a 3D volume. The 3D volume is a microCT scan, while the 2D image is taken from a plane passing through the ...
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image registration using fft

I'm trying to register 2 images.First image don't change and second image is changing at each iteration by homography matrix and I'm using minimizer to find maximum of phase correlation, but for some ...
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2answers
1k views

Image Registration by Segmentation

Image registration algorithms are usually based on point features such as SIFT (Scale-Invariant Feature Transform). I saw some references to line features, but I was wondering if it would be possible ...
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How do I evaluate the performance of a segmentation algorithm?

I'm currently on a project of liver tumor segmentation. I segmented the liver using region growing, and I have to assess how accurate the result is. I recently learnt that there are certain metrics ...
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How to compute 2D displacement vector for binary image registration?

My inputs are several binary images like: They have globally the same content but may be unregistered as they are produced from a hand camera. What I would like to compute is the 2D displacement ...