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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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 ...
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1answer
33 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 ...
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1answer
29 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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20 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
39 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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39 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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16 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
47 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 ...
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37 views

5-point algorithm giving strange results

I am using the 5-point algorithm code from https://github.com/prclibo/relative-pose-estimation. I set up a test: ...
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15 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) ...
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1answer
84 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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0answers
85 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
29 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 ...
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1answer
50 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 ...
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1answer
56 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
79 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
48 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
54 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 ...
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2answers
162 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
74 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 ...
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1answer
28 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 ...
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1answer
51 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 ...
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2answers
73 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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31 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 ...
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1answer
75 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 ...
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1answer
92 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?
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1answer
66 views

Dynamic Textures

i know that texture refers to surface characteristics and appearance of an object given by the size, shape, density, arrangement, proportion of its elementary parts. But i am more interested in ...
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1answer
72 views

Computer Vision/Image Processing Riddles [closed]

I know this topic is not clearly relevant to the forum, but I think it's fun and interesting. I'm looking for computer vision riddles - fun and interesting questions that have a clear and precise ...
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29 views

What are the various techniques for detecting Walls in the Building(Architectural) floor plan Images?

I have to process building floor plan images to extract Walls from the structure. It is trivial in case of binary images; but the images in our case are colored, and each have different color of ...
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1answer
29 views

Incremental Online Update of Tf-IDF Indices for Image Retrieval

In their paper "Scalable Recognition with a Vocabulary Tree" (http://www.vis.uky.edu/~stewe/publications/nister_stewenius_cvpr2006.pdf), Nister and Stewenius mention that after an offline training ...
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1answer
62 views

Adding measuruments noises to kalman filter

I'm implementing navigation system for my robot. There are two ways to get data from it: odometry(encoders from motors) and camera. Both of information sources can give me estimate of robot's ...
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20 views

Is there an OBJECT BASED Image Segmentation method, with pure non-segmented training images?

I wonder if there is a method works as follows: 1) The algorithm is trained with some images of a particular object (I train my Image with 1000 banana images) 2) I use the training data to segment a ...
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1answer
34 views

need general resource about image matching

i'm working on image matching mainly SIFT and SURF for my thesis. i read Moravec's and harris corner detectors and understand them quiet well in my own opinion.A COMBINED CORNER AND EDGE DETECTOR[1] ...
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2answers
53 views

how to make image editing filters

I am trying to make filters for days but now I just want to know the experience of others rather than go on to wrong way and finally decided to put my query over ...
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1answer
51 views

Computer Vision Libraries for PHP

Are there any computer vision libraries in PHP, or any server-side programming languages? If not, maybe we can make a list of some -already implemented- methods (Viola Jones face detector, landmark ...
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83 views

How to extract the vein pattern from an IR image of finger?

I am trying to isolate (or segment to be precise) the vein pattern from Infra red image of a finger (using MATLAB) like shown below: So my output will be a binary image like (not the exact dimension ...
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102 views

How to make color balance of photoshop using opencv

I want to make the same thing programmatically like Color balance in Photoshop , like in below image if we have same bar ...
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0answers
61 views

How to get the depth value of a ball from a disparity map

Hi I am writing a program which retrieves the z coordinates of a ball from a disparity map. I am using the EmguCv wrapper class. At present I have a lot of elements working although admittedly not ...
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2answers
77 views

Techniques to reduce delay in detecting face from video using vision.CascadeObjectDetector in matlab

I wrote matlab code for face detection.In my code it is detecting face for first 100 frames and it crop faces from each frame and saves it in database folder.Problems iam facing 1.Detecting face ...
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1answer
53 views

Feature for exact matching of images

I am trying to match images from a large dataset which exactly match the given input image.(images with deformations/transformations are treated as different) I have tried euclidean distance but it ...
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3answers
66 views

Trying to translate formula for blending mode

I am using OpenCV C++ for making the blending mode like in photoshop, I want to make overlay mode in it. I search its alternate in OpenCV in which I found this ...
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37 views

How vibrance method of photoshop work in opencv

Can somebody please explain how Photoshop vibrance function can use in opencv c++ ? so that I may reproduce the same effects in my application. Here is the vibrance ...
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1answer
80 views

Counting human movement of exercise using ROI or pre-set passing line with OpenCV

I'm currently doing my final year Degree in computing studies. The project I'm working on is a video of a webcam or computer webcam to have 2 pre-defined ROI (Region of Interest) on top and bottom ...
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35 views

Classifying images with standing\sitting people

I have images that contain two people. They can be divided into the next categories: Both people are standing. One person is standing, and one is sitting. Both are sitting. I want to classify each ...
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0answers
9 views

Histogram as a feature in Make3d

I am reading the one of the publications of the Make3d project. the NIPS one. which uses a machine learning approach and MRF to estimate the depth from a single image. In this paper in part 3.2 the ...
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2answers
71 views

Eigen value and Eigen Vectors in Image Processing

I have been reading about eigen values and eigen vectors but i haven't be able to find any decent explanation relating their application in image processing/computer Vision for example say face ...
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27 views

base curve detection and skew estimation in Binary Document analysis

In document image analysis i came across two differnet sets of literatures. One is skew estimation of text lines and other is base curve detection of text lines. My questions are:- How the two ...
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15 views

How to use cross-ratio in position estimation?

I'm trying to track the horizontal motion of a pen's tip using a single camera. My current approach is to use the Cross-Ratio between 4 colinear points. My idea is to place 3 LEDs along the pen's ...
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33 views

What does normalizing gradient means?

Since my algorithm needs to detect long, coherent edges, the estimated local magnitude P for each pixel is normalized with respect to the magnitudes in it’s local neighborhood W (i.e., a 5x5 window). ...
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1answer
46 views

Best Guess Rectangle

I am using openCV to find a particular object, and am trying to find a way to make it locate the object consistently. The object's location will be determined by taking 30 frames and trying to find ...