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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18 views
Affine detector + SIFT descriptor
I am approaching to the Oxford Buildings dataset which contains already computed SIFT descriptors from affine detected keypoint locations.
Usually SIFT detector provides to its detected keypoints ...
-1
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0answers
48 views
Subtracting frame from video and write it again as video [closed]
I am capturing and saving frame from video. I want to subtract the current frame from previous frame and write it again as separate video. The program below is how I tried to implement this, but its ...
2
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0answers
45 views
Estimating Plane Pose Without Knowledge of Intrinsic Camera Parameters
Assume a camera has no skew, and has square pixels, that is, its camera-calibration matrix, $K$, looks like:
$$
K = \left[\begin{matrix} \alpha&0&u_x\\0&\alpha&u_y\\0&0&1 ...
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1answer
68 views
Image processing: using PCA for 3d object recognition
I read this lecture on using PCA/eigenfaces: http://www.cse.psu.edu/~rcollins/CSE486/lecture32.pdf
And I want to use this general procedure to recognize a 3D clay model that I took pictures of from ...
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0answers
31 views
Fourier Transform Computer Vision Textbook
I am required extremely fast to fill the gap and learn Fourier Transform with application in Computer Vision.
It was easy to find mathematical aspects of Fourier Transform, but I am more interested ...
4
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0answers
44 views
Help in Retraining HOG Descriptor using SVMLight
I am currently trying to count car using OpenCV 2.4.4 with HOG descriptor. Because model for car detection is not available in OpenCV (unlike people detector which already have model for the ...
1
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0answers
35 views
Geometric models to discard image features
I am working on the implementation of a location recognition pipeline as detailed in the section 5.4 of the paper Leveraging 3D City Models for Rotation Invariant Place-of-Interest Recognition:
...
6
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0answers
103 views
Counting vechicles in an image
I have been trying to implement an algorithm for successfully counting cars in an image. I have tried implementing A Method for Vehicle Count in the Presence of
Multiple-Vehicle Occlusions in Traffic ...
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1answer
35 views
Intensity change after filtering this image?
I need to filter the image raster below with the following mask:
0 1
-1 0
and the Image Raster:
...
3
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0answers
67 views
Points of interest in a spectrogram
We have several audio tracks, all of which are different versions of the same track under one type of distortion: the speed of the track is increased by a constant factor K (hence frequences are ...
0
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0answers
28 views
Blind signal separation on mixed images using FastICA
I have a grayscale image, which was obtained from a set of images randomly mixed. I would use the FastICA algorithm in order to retrieve the original images, but the number of original images is not ...
1
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0answers
12 views
How canparticle filter help me with reconstruction/separation of blobs
I'm on people tracking in computer vision. I have observations (blob as output of blob detection after background subtraction) and i want to infer the objects that have produced this observations.
My ...
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0answers
19 views
Searching for image samples in order to create custom classifier
I am training a classifier of my own, specifically for detecting body arms. According to the training process I have to provide positive samples and negative samples, wich will be used in the ...
2
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1answer
51 views
MATLAB: Why my Pixel Indices are so different from that in Spatial Coordinates
The question is revised to make it more specific and constructive.
I am doing imtransform, yet the xdata and ydata are very much different from that of size(output).
[ output, xdata, ydata ] = ...
2
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2answers
41 views
Training custom classifiers using trainCascadeObjectDetector
Is there any good documentation about training your own classifiers(with examples included) different from this one provided by MathWorks.
Thanks in Advance
2
votes
1answer
58 views
What is the state-of-the-art method for dealing with illumination issues in background subtraction?
I have been struggling to find a well-cited approach to this. Essentially, I am experimenting with different background subtraction algorithms, but none seem to perform well when there are ...
1
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1answer
41 views
Properties of projected 3d points (to 2d), Principal component analysis (PCA)
This question is a little theoretical. Say I have 3 points that are bound within a certain 3D volume of some shape (i.e. box, cylinder, cone, etc). By using PCA, I find the most two dominant ...
4
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4answers
141 views
Detect lanes from a filtered image
I am working on lane detection system and I would like some suggestions from you as to how to detect lanes from a filtered image which I got after performing certain operations. Firstly, I should ...
1
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1answer
74 views
Alternative to support vector machine?
I have to make comparison between 155 image feature vectors. Every feature vector has got 5 features.
My image are divided in 10 classes.
Unfortunately for using support vector machine i need at ...
1
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1answer
59 views
Object Classification using pyramid match kernel
I have been reading up on the pyramid match kernel as an alternative to using the bag-of-words model for object classification using a SVM. The bag-of-words model provides a model for transforming a ...
4
votes
1answer
168 views
Image processing and the Fourier Transform
I am trying to understand how and why the fourier transform is used in image processing / computer vision. Below is what I have gathered so far. Would my understanding of it be correct? If not, could ...
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0answers
68 views
How to relocate face points in opencv / face distortion?
I have to simulate facial expressions on a face image ( say open mouth ). For this I first extracted the facial feature points and found the corners of the lips. Now I need to deform the image by ...
0
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0answers
32 views
Evaluation of Keypoint Detector and Feature Descriptor Combos for Vehicle Detection
I am currently doing a research project into the effectiveness of different keypoint detector and feature descriptor combinations for the task of vehicle detection.
At the moment I am using a SVM for ...
4
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0answers
46 views
What is a good distance measure for matching SIFT descriptors depending on the distribution of their noise?
I have read some papers about distance measures like Euclidean, Manhattan or Chi-Square for matching gradient based image descriptors like those computed from the SIFT Algorithm (128-D vectors). Most ...
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1answer
68 views
How to calculate Noise and distortion of an image?
I need to make an application in iphone which needs to calculate noise, geometric deformation other distortions in an image. How to do this? I have done some image processing stuff with opencv + ...
3
votes
1answer
114 views
Recognizing hand-written archaeological signs
I have 75 images of handwritten signs from which I extracted 7 Hu moments and solidity features. How can I find similarities among them to train a classifier and predict the value? I thought SVM was a ...
2
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0answers
25 views
Phong Reflection Model Parameters
Question: Can anyone refer me the Phong reflection model parameters for a face image taken for web-cam?
Details:
I am doing 3D reconstruction of 2D images using 3D Morphable Model as in this paper ...
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2answers
92 views
Steps for recognizing hand written signs
What are the steps to built a system which recognizes hand written signs in an image and returns the most similar sign in Python? I know that depends on the image and many variables, but isn't there a ...
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0answers
61 views
Perspective Projection of a 3D head to form a face image
Input: 53490 3D points and for each point (xyz) and color (rgb) of a head
Output: 2D face image as viewed from a particular position / direction
Platform: Matlab C/C++
After study, I found the ...
1
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2answers
90 views
filter for reducing background noise in image
I have images where there is a lot of "black" background (few shades of black). (In many images at least half the pixels are background). I need to get interest points from the image, but because the ...
0
votes
1answer
81 views
best robust feature detectors for detecting similarities among archeological signs
I would like to implement edge detectors for creating a feature vector for archeological signs.
Which are best features, algorithms to retrieve? That could be loaded in a Support vector machine for ...
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0answers
34 views
OCR Implementation: Matching input with font data file
I have an idea of creating handwriting recognition app, for practice in machine learning skills. Just found useful link here
So dunno how awkward that sounds but so far what I've done is created ...
0
votes
1answer
49 views
Is the Canny algorithm enough for creating a feature descriptor image for input to an SVM?
I retrieve contours from images by using the Canny algorithm.
Is this enough preprocessing to have a descriptor image for input into an SVM to find similarities?
Do I need other features like ...
8
votes
3answers
177 views
Gesture recognition using only simple techniques
I'm following a computer vision course and I have this exercise: write a program that, given an hand image, it can recognize if the hand is open, closed, in a punch, or holding an "ok" posture, using ...
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2answers
167 views
Any references for the trade-off between software and mechanics/optics in industrial machine vision systems?
I explain my question with a simplified example.
I can design an industrial vision system for the automatic inspection of an item with these main requirements:
the image of a good piece must be a ...
3
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2answers
137 views
Digital image moments in plain English
I'm studying OpenCV and, in computer vision and image processing, people speak of blobs, contours, connected regions, and I sometimes hear the phrase "image moments".
I know of an article on ...
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0answers
38 views
Looking for algorithm to extract line network from binary images [duplicate]
Possible Duplicate:
Looking for algorithm to extract line network from binary images within LabView
I would like to create a LabView VI that receives an input image and the RGB-color codes ...
1
vote
1answer
94 views
Looking for algorithm to extract line network from binary images within LabView
I would like to create a LabView VI that receives an input image and the RGB-color codes of the powerlines depicted in the image. The output should (eventually) consist of id'd polygonial connections ...
0
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0answers
112 views
Using GavabDB for 3D face reconstruction from frontal image
Project: 3D face reconstruction
Input: 2D frontal face Image Output: 3D face Reconstruction and expression simulation Platform: Matlab or Opencv cpp.
I found out after study that 3D Morphable Models ...
2
votes
1answer
93 views
Safe Point Thinning Algorithm - How to?
I am relatively new to image processing and am working on a project that requires the thinning of binary images. In the literature, I've seen references to the Safe Point Thinning Algorithm(SPTA) ...
3
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0answers
82 views
Qualitative Evaluation of Interest-Point-Detectors and Descriptors in Computer Vision
I'm writing on a qualitative evaluation study of interest-point-detectors and descriptors. I've read all Mikolajczyk papers as well as most of the surves from Datta et al. etc. Now I'm implementing an ...
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0answers
61 views
STASM or AAM which is more efficient
I am working in face detection and recognition project. I am using STASM for face detction and locating face landmarks. On googling I found AAM (Active Appearance Model) and found that it is also used ...
2
votes
1answer
147 views
Matching features points of rotate image using SURF
I'm trying to match SURF points between 2 images using SURF with opencv. One is the rotation of the other.
The problem is that the few matching it can found are wrong.
image of matching points
I ...
0
votes
2answers
52 views
What is the procedure to obtain a 3D face dataset? Can anyone suggest a good 3D face dataset?
Project Description:
Input:
Frontal Face Image
Expression
Angle
Size
Details:
I have to convert the input frontal face image into 3D face and simulate the ...
0
votes
0answers
43 views
Repair gaps in image and “reconnect” connected components
I am working on an image recognition application that processes groups of connected pixels and classifies these.
Sometimes, due to sampling errors some pixels that should be connected are not.
What ...
7
votes
3answers
639 views
Scale and Rotation invariant Template Matching
I'm looking for a method for scale and rotation invariant Template matching. I already tried some, but they didn't work so good for my examples or took for ever to execute
.
SIFT and SURF Feature ...
2
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0answers
68 views
Projection Matrix (Computer Vision)
I'm trying to understand a piece of code that is using a camera projection matrix. The camera projection matrix $P = \left[\begin{array}{c}p_1^T \\ p_2^T \\ p_3^T\end{array}\right]$ takes a point $X$ ...
9
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2answers
219 views
Segmentation of half transparent material, e.g. glass
I'm totally stuck on an issue regarding the segmentation of glassy objects.
I need to get the object as precise as possible.
My approaches were different.
At first I tried to remove the background, so ...
4
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1answer
127 views
Compare image segmentation approaches
I've got a question related to a comparison of image segmentation algorithms.
I'd like to compare two algorithm results to each other in step one.
In another step I'd like to compare the two ...
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0answers
25 views
A few queries about 'Joint Image and Word Sense Discrimination For image Retrieval'
I had a query regarding the model used in the paper here. What would be the problem in going for a hierarchical clustering approach?
What they did:
We solve problem (ii) by cross-validation, trying ...
