Computer vision includes methods of processing, analyzing, images and high-dimensional data to form high level understanding and recognition of the scene or images.

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14 views

Normalized cut segmentation output correct or not?

I have implemented "normalized cut" segmentation. The change here is that, instead of giving an image as input, I have given an matrix of image. As my output looks odd to me. I need to know whether my ...
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2answers
25 views

LoG filter creating additional maxima in scale space

To create a scale space, I applied a Laplacian of Gaussian filter on the following image: After the scale space was created, I plotted circles around local maxima in scale space. However, instead ...
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1answer
34 views

AGAST vs FAST evaluation

In ~2006 the FAST corner detector was introduced. One of it characteristics is that you have to train a decision tree from some test image in order to learn the types of corners present and relevant ...
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1answer
21 views

Skeleton from distance map

Can anyone give some tips how to obtain Skeleton from distance map? I already managed to obtain skeleton using erased method (e.g. zhang suen) but it's time consuming because it's an iterative method ...
0
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1answer
39 views

Classifying animated GIFs as animation or film

Is there any known way of differentiating between frames of real footage and animated content? It seems like there's probably range of colors more likely to appear in a histogram for real footage, or ...
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0answers
16 views

Useful features for classifying color images

I have two sets of images. In one set, the background and foreground differs significantly in color (either background is dark and foreground is light or vice versa). What would be some useful ...
0
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0answers
10 views

Switching gradient computation in Lucas-Kanade pyramidal feature tracking

The following refers to pyramidal Lucas-Kanade. Given two images $I$ and $J$, we wish to find point $v$ in $J$ which corresponds to point $u$ in $I$. The initial step of the algorithm requires ...
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1answer
9 views

Equal contribution criteria during image pyramid construction

In their paper on Image Pyramids, Burt and Adelson state the following about pyramid generation. An additional constraint is called equal contribution. This stipulates that all nodes at a ...
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0answers
16 views

Sliding Windows, Global Image, Clustering and …?

Imagine that you have an algorithm that must detect some feature in an image. Right now, I know three "families" of search algorithms. Sliding Windows: You take a patch of some size (e.g. 15x15 ...
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1answer
43 views

Rectangle detection in “real life” images

I have seen a lot of posts here and on SO and on various websites, using Matlab, OpenCV, name it, on how to detect rectangles in an image. I have done it myself too, using Matlab. My usual steps were: ...
2
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2answers
47 views

Would the locations of SIFT features generally agree with features detected by Shi-Tomasi method?

I am having a comparison of different feature detection methods. So if we compare the SIFT (Scale-invariant feature transform) and Shi-Tomasi method, will their feature locations agree and why? Are ...
0
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13 views

.ptw Video conversion

On Video recording with IR camera, a file in .ptw is obtained. I want to analyze the file using standard software, like MATLAB. However, video processing in MATLAB requires the file to be converted to ...
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1answer
52 views

How to constrain the object detection problem?

How to constrain the object detection problem? It would be tempting to ask for precision such as: "It depends, does it have to be viewpoint invariant, is there going to be viewpoint changes, etc.?" ...
3
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1answer
75 views

Academic problem solving in Computer Vision

I am currently pursuing a Master degree of Engineering and I will have to write a thesis about solving a specific Machine Vision application. I have done some CV projects in the past but now I am ...
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1answer
35 views

Why does an ideal high pass filter on this image generate gray values

As seen from the image below, an ideal high pass filter was applied. Hence, stark changes in pixels from lighter to darker or vice versa show up on the filtered image. However, slower changes such ...
0
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0answers
19 views

Bhattacharyya distance for image segmentation explanation

I have a question need some your suggestion. I spent 2 months to resolve that problem but the result is not so good. Hence, I would like ask you some thing about my implementation. My goal is that I ...
1
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1answer
58 views

Histogram Intersection with two different bin sizes?

I have two images: A and B. Image A is a screenshot of image B, the original image. While there is noise in image A, the original features are still distinguishable. Histogram intersection tells us ...
0
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1answer
74 views

Separate sub-figures!

Any idea on separating multi-panel figures? There are 2 different sub-figures connected each other. Thanks!
1
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1answer
131 views

How to detect whether the object has triangular shape?

The task is to detect arrow from medical images. After segmenting, arrow-like objects can be connected with other connected components (noise). In this context, detecting a part of the object that ...
4
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1answer
84 views

The small red peak in the CIE standard observer

The human eye has 3 types of color cones: red, green and blue. Their spectral sensitivity peaks in short (S, 420–440 nm), middle (M, 530–540 nm), and long (L, 560–580 nm) wavelengths. See diagram ...
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27 views

Problem in openCV casade classifier

I am trying to train cascade classifier using "opencv_traincascade" utility. I'm having 100 positive images and 500 negative images. I have created .vec file using following command: ...
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0answers
25 views

Best method for texture classfication

I am working in medical and nature images processing . I want to find a popular method to segment texture image. Could you suggest a popular method to do it? For example: Gabor filter, tensor...
-1
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1answer
65 views

Low pass filter to maintain edge information

I am looking for a kernel acting as a low pass filter that satisfies these conditions: $$K(-\mathbf{u})=K(\mathbf{u}) \tag{1}$$ $$K(\mathbf{u}) \ge K(\mathbf{v}), \;\; \text{if} \;\; ...
0
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1answer
64 views

Comparison between average kernel and gaussian kernel?

In image processing, we have two kinds of major kernels that are average kernel and gaussian kernel. For image segmentation, which is difference between average kernel and gaussian kernel? I found ...
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1answer
52 views

Real Time Object Tracking using image processing [closed]

How we can track a single selected object from multiple detected moving objects using single fixed camara?
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1answer
40 views

Floating point Descriptor evaluation

I have come up with a new descriptor(floating point). I want to evaluate this descriptor against SIFT, GLOH, etc etc. I am using the K. Mikolajczyk, C. Schmid, approach. The method is described in ...
0
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1answer
51 views

How to detect a inhomogeneity region in image

I have an image that includes object and background. However, the object appears some inhomogeneity region due to illumination. My work is that how to detect inhomogeneity region. Which is feature can ...
0
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1answer
31 views

How to choose the number of codewords in bag of words model

In the bag of words model, generally is it better to have more codewords or less? For example, if I have 1000 x 20 raw features, then what would be good value for codebooks? I am thinking of smaller ...
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0answers
23 views

High triangulation error

I have implemented a 2D->3D point triangulation method, which uses 2 poses P1 and P2 and 2 points back-projected to z=1 point1 and point2 to recover depth: ...
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3answers
57 views

Camera Calibration using Single Input Image

Given a camera, permanently located at the same position, angle and distance from what is being captured, and a single calibration image ( a row of vertical lines [ | | | | ] ), how would one go about ...
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0answers
46 views

Find and track deformable curve in noisy images

I need to find and track the location of the bottom of multiple deformable curves within a sequence of images. The images are taken roughly 5 seconds apart and there can be considerable deformation in ...
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0answers
27 views

Affine Parameter Optimization using simulated annealing

I am working on a project to compare images in the database. I use color and gradient orientation as features of the image and these features are not rotation invariance, therefore to compare well I ...
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0answers
163 views

Train a Cascade Object Detector in MATLAB

I am trying to train a cascade object detector in MATLAB using the built in functionality from the Computer Vision Toolbox. I’ve taken 500 photo’s of the sole of my shoe. Every photo is taken from ...
0
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0answers
20 views

Fastest implementation of Features from Accelerated Segment Test (FAST) algorithm

I understand that there are different implementations (both in software and hardware) of the FAST algorithm. What is the fastest implementation of Features from Accelerated Segment test (FAST) ...
1
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1answer
203 views

Zernike Moments' implementation in OpenCV

The reason why Hu moments were implemented in OpenCV and why Zernike moments were not implemented is looking like their performance similar as stated in this paper. As stated in the paper Zernike ...
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164 views

MPEG-7 descriptors' implementation in OpenCV

I'm looking for implementation of MPEG-7 descriptors which are compatible with OpenCV's recent versions and containing "region-based shape descriptor ART(Angular Radial Transformation)". I ...
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1answer
32 views

How to recognise partial text on mechanical indicators

I would like to know is there any possible approach to recognise digits of the first (and second as well, as you can see in the example figure) order of magnitude. I've thought of neural network with ...
2
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1answer
70 views

Planar Homographies in MATLAB

I have taken an image in height 2 meters of the ground as the original image and I want to simulate another image in 50 cm's of the ground, such as the simulated image. The focal length of my camera ...
2
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2answers
88 views

How do we distinguish between Image Recognition,Detection and Segmentation?

I am reading image processing book.while reading i am getting terms like image detection,image recognition and image segmentation. it seems that all above terms are one and the same.i am totally ...
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2answers
100 views

Ship/Boat Detection

I want to do boat detection in almost real time around 2-3 frames/sec and my computation power is not very high. I want to keep the computations as low as possible. Which is the best method to do it? ...
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1answer
72 views

How to warp a pixel patch to another camera

I have two cameras with rotation and translation starting from the world origin and a patch in the first camera's reference coordinate system. I want to warp this patch into the second camera's ...
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2answers
61 views

How to proceess Image with curved corners and edges to give sharp Corners?

I have several Images of shape H, F, I, L.. which have curved corners. How do I process them to give sharp right-angled corners? I tried approximating them with inner rectangles, but this takes a LOT ...
4
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2answers
277 views

Is it possible to convert from 2D to 3D form?

I have captured car positions at different frames from the video. Suppose car's(e.g.left side car which is coming towards us in the images) centroid at video frame1 is P(x1,y1) and Q(x2,y2) at video ...
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1answer
115 views

Background subtraction for object tracking

i am working on object tracking. i want to use background subtraction. i have tried to find out papers on background subtraction but i am really confused to use which one. I have already done tracking ...
0
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1answer
30 views

which spatio-temporal properties does dynamic textures exhibits?

know that dynamic textures are spatially repetitive and temporally varying patterns. 1.I read one sentence in one paper i.e. They are sequences of frames exhibiting certain stationarity properties ...
0
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1answer
61 views

Projecting a 3D point into new camera coordinates

Given I have: a camera with estimated rigid motion 3x4 matrix $P = [R|t]$ that starts from the origin of the reference coordinate system an intrinsics 3x4 projection matrix $K$ a 3D point $X$ How ...
0
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2answers
108 views

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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0answers
44 views

CBIR with ORB Feature

I've read the papers (ORB: an efficient alternative to SIFT or SURF), and i believe the step-by-step of ORB to be like this : (1) FAST detector -> (2) Filtered FAST (by Harris) -> (3) Multi-Scale ...
1
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1answer
83 views

What is the Difference between Texture and Image?

I am beginner in the image processing I want to know what is difference between Texture and Image? or whether they are same? can anyone explain it. Also,if i want to do texture segmentation,can i ...
1
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1answer
271 views

Train Cascade Object Detector example in MATLAB

I am trying to use the example from here to detect a stop sign. But when I change the image to search for stop signs in there are a huge number of false positives. Am I doing something wrong?