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0
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1answer
17 views

Getting the essential from the fundamental matrix

Is it possible to get E from F? I suppose that can't work, because then I could calculate the the extrinsic (and maybe also intrinsic?) parameters of the cameras without a calibration object of known ...
2
votes
1answer
8 views

Fundamental and essential matrices, value of intrinsic parameters

I observe a scene with two cameras, c1 and c2, that produce two images i1 and i2, respectively. What I ultimately want to do is to use information of image i1 and image2 simultaneously, e.g., for ...
0
votes
1answer
33 views

Bringing images into alignment

I observe a scene with two cameras, c1 and c2, that produce two images i1 and i2, respectively. What I now want is to bring i1 and i2 into alignment, that is I want to know where pixel (x,y) in i1 is ...
1
vote
1answer
22 views

What is the reason of using Gaussian model for Background Modeling?

I am a new learner to Background Subtraction (Background Modeling) and I am reading a few previous works on how it is performed. Starting with Wikipedia (by searching "Background Subtraction"), I ...
0
votes
1answer
16 views

Time complexity of a vertical sweep algorithm with histogram computations

In the paper Quick Detection of Brain Tumors and Edemas: A Bounding Box Method Using Symmetry, Saha et al the authors claim that the running time of the algorithm (Matlab implementation) is ...
-2
votes
2answers
265 views

Google's Deep Dreamer

I was just wondering on a more technical side, if anyone could explain what Google does to create these amazing images from it's deep dream system. Could anyone explain to me in a step by step way, ...
1
vote
0answers
26 views

find the actual size of an object from pixel coordinates

I am quite new to vision and OpenCV, so forgive me if this is a stupid question but I have got really confused. My aim is to detect an object in an image and estimate its actual size. Assume for now ...
1
vote
1answer
26 views

How to test image segmentation algorithms? [closed]

What would be an ideal environment/manner to judge the effectiveness of multiple segmentation algorithms? The goal is to determine which algorithms provide the best results for pre-clinical imaging. ...
0
votes
1answer
30 views

How do I detect and rotate a square?

I have recently written code for detecting path colors in a 2D grid and printing the corresponding path costs and it works fine for me. Here's my code; I am currently new to OpenCV and know only C++ ...
-1
votes
1answer
44 views

How to identify and find navels from human pics

I have a specific question and not sure what tools I can use to finish my projects. I know this may has been well solved, but I am quite new to the image recognition and detection area and don't know ...
4
votes
0answers
59 views

How to calculate Huffman code length without generating the actual huffman code?

Given a vector of elements, how can I calculate the length of the Huffman codewords without generating the Huffman code itself? Using Matlab, I was able to compute the Huffman code and and get the ...
0
votes
1answer
34 views

Couldn't understand the topics “Hough transform mapping” of the paper named “Text line and word segmentation of handwritten documents” [on hold]

I am doing thesis on "Segmentation of handwritten documents". My problem is i couldn't understand hough transform of Text Line Segmentation of "Text line and word segmentation of handwritten ...
0
votes
0answers
21 views

Compare phase and magnitude spectrum results of 2 Images

I have read that from Fourier transform we obtain magnitude and phase spectrum. The magnitude spectrum tells you how strong are the harmonics in a image and the phase spectrum tells where this ...
0
votes
0answers
13 views

Which algorithms are suitable for detecting biological pattern formations?

I'm looking for approaches to automatic detection of biological pattern formations in digital images, similar to those displayed on this wikipedia page: Patterned vegetation The framework i'm working ...
1
vote
1answer
89 views

The Fundamental and Essential Matrix

Could someone, in plain english, explain the distinction between the fundamental matrix and the essential matrix in multi-view computer vision? How are they different, and how can each be used in ...
1
vote
0answers
36 views

Computer vision training procedures: SVM/AdaBoost vs Neural Networks

With SVM, adaboost or similar alogrithms, image training sets must be cropped with specific constraints (keep image cropping ratio the same, have object tightly cropped, same resolution) In general, ...
0
votes
0answers
22 views

Any good algorithms for 3d volume alignment by feature extraction, especially ones involve machine learning?

I am trying to align 3d mri brain images of different rat individuals. I have dozens of examples that have been aligned manually, which are good resources for machine learning. I am considering ...
1
vote
1answer
48 views

Can you determine rotation/camera calibration from series of images separated by pure rotation

I have a series of about 50 images, each separated by a small rotation and taken from the same camera. The images are feature-dense, and I can calculate a homography from image-to-image easily. My ...
0
votes
0answers
42 views

Is there a way to tell a picture has been resized?

I need to evaluate if the picture was resized (upscaled). Are there any approaches to that already? If not, what do you recommend me to start with?
-1
votes
1answer
32 views

What is the exact definition of a dictionary in the concept of linear algebra and computer science?

I am reading this paper for my master thesis and trying to understand every concept in it. The following sentence confuses me as to what is the exact definition of a dictionary in this concept except ...
-3
votes
1answer
56 views

Digital Image Processing

I'm a Computer Science Graduate but I didn't study digital image processing during my college years. Now I'm thinking of learning it, but I'm little bit confused about where to start. Is there any ...
0
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0answers
29 views

Histogram equalization - to increase “punch” and to limit local gain

The exercise 3.6 (Histogram Equalization) in Szeliski's Computer Vision - Algorithms and Applications asks: Convert the color image to luminance (Section 3.1.2). Compute the histogram, the ...
2
votes
1answer
402 views

How to Know Whether a Topic is Publishable in Computer Science

Forgive my ignorance, but I am very new to the publishing process in Computer Science. I have some research that I have done involving analyzing data formats used in web-based image processing ...
1
vote
1answer
122 views

How can GIF compression be lossless if the maximum # of colors is 256?

I'm reading "Computer Science Made Simple" by V. Anton Spraul, and in the chapter about Graphics, he describes GIF files as follows: A GIF file uses lossless compression to store an image with a ...
0
votes
0answers
25 views

Learning Hierachial representation of objects in a unsupervised manner

I am trying to understand how the how a hierarchal representation of an object can be learned in a unsupervised manner, using the method described in this paper. ...
1
vote
0answers
67 views

How to identify the z-ordering of objects in a computer vision or image processing scene?

Given that there is an image with objects in it, is there any method in computer vision to determine the z-ordering of objects. For an ideal image of three circles overlapping, I can determine that it ...
-1
votes
1answer
110 views

Blob detection as Constraint satisfaction problem?

In image processing I have a black and white image which is represented by matrix {0,1}, I have to find blob (a region of connected pixels) in it. I'm confused, can this problem be reduced to ...
1
vote
0answers
29 views

Efficient flood filling (seed filling)

I am referring to the algorithm that fills a white area of arbitrary shape in a binary digital image, starting from a given white pixel, using the Moore (8 neighbors) or Neumann (4 neighbors) ...
2
votes
1answer
17 views

Determining width of paths.

I have an image that I will have below that has different paths. I want to be able to detect the thin parts of these paths and highlight them. What is the best way to go about this? I will do my best ...
1
vote
1answer
52 views

Finding approximately collinear points

my issue comes from image processing. The image below is for a better understanding of the problem. I have to detect three dots (shown in black, marked with red arrows). The other points I get from my ...
0
votes
0answers
80 views

Technique behind the way google earth overlaps polygons on top of pictures

What´s the technique behind the way google earth overlaps polygons on top of pictures(like the ones users assign to streets and houses) ? It seems to be aware of perspective, and I don´t remember ...
3
votes
0answers
68 views

Simplify closed-path points without intruding into the inside of the path

I want to: Simplify a set of points that outlines a closed opaque image on a transparent background. The simplified set of points should not intrude into the closed opaque image. I use a ...
1
vote
0answers
139 views

Improving MSE as fitness function for a genetic algorithm

I am implementing an autoencoder neural network in matlab, the weights of which are being optimised by a genetic algorithm. At the moment I am working on the first layer, trying to get an improved ...
3
votes
1answer
157 views

Extracting features for texture classification

I m a beginner in the field of pattern recognition and computer vision. I m working on a project right now to classify t-shirt patterns into three categories i.e. solids, stripes and checks. I have ...
-1
votes
1answer
55 views

Selecting a M.S. in CS focus [closed]

I need to pick a focus in my Masters program. The running candidates are Networking Bioinformatics Data mining Computer Image Recognition In order to avoid this becoming a discussion, I'd be ...
3
votes
1answer
177 views

Training and testing image sizes for classification in computer vision

When training a classifier for object detection using features extracted from images (eg HoG features), how important is it that the images used for training fed into the classifier in their natural ...
2
votes
1answer
155 views

Method to recognize abstract objects such as hand-drawn objects?

My research is in the area of Document Image Analysis. To be specific, the topic of my thesis is to automatically recognize and index characters in a set of hand-drawn objects, e.g. given a volume of ...
5
votes
2answers
172 views

What are all the differences between the Gibbs phenomenon artefects and JPEG artefacts?

I thought the Gibbs phenomenom is the result of Fourier analysis estimation (but was it Fourier Series estimation or can it also be Fourier Transform estimation?) JPEG uses the Discrete cosines ...
2
votes
1answer
52 views

Resizing and aliasing in computer science [closed]

If you resize an 1000x1000 raster image to 10x10 and resize it back to 1000x1000 is this considered to be an example of aliasing?
7
votes
1answer
104 views

Recognizing waterways in an aerial photo — polygons from edge detection images

I am trying to recognize waterways from aerial photographs (say from Google Maps). Local governments often have GIS data that says where the waterways (and roads, buildings etc) are, but the water ...
3
votes
2answers
41 views

How do I apply patch sized features to larger images?

I've been trying to teach myself some machine learning, and I wanted to ask what seems a simple question, but I've not been able to find any resources that explain the next step. Let's say I am doing ...
1
vote
1answer
58 views

How to compute Gabor feature vector?

I'm working on semi automatic texture segmentation using level set and gabor feature vector described by Manjunath und Ma [1]. I consider their feature representation is better than others since I ...
0
votes
1answer
347 views

Number of different output labels in Local Binary Pattern

I'm studying about Local Binary Pattern and I'm having trouble understanding the following part about the number of output labels for binary patterns from Computer Vision using Local Binary Patterns, ...
2
votes
1answer
210 views

How to count near circular objects in image

I have a image similar to below. In that I need to find all red circles and count them. So, I am thinking to use MATLAB R2011a with Image Processing Toolkit for it. How could I possibly extract them? ...
2
votes
1answer
56 views

How to evaluate the accuracy of a method for the extraction of the principal lines of the palmprint

Let's assume that I've implemented a method for the extraction of the principal lines of the palmprint. For instance, let's say that I'm able to do a transformation like the following one (image from ...
2
votes
4answers
121 views

Environment detection - How to detect “city” versus “landscape” background environment in computer vision?

I'm searching for computer vision or machine learning algorithms/methods that are used to classify or differentiate two outdoor environments. Given an image with vehicles, I need to be able to detect ...
1
vote
1answer
165 views

Making feature vector from Gabor filters for classification

My aim is to classify types of cars (Sedans,SUV,Hatchbacks) and earlier I was using corner features for classification but it didn't work out very well so now I am trying Gabor features. code from ...
3
votes
1answer
52 views

Environment requirement in training image dataset for classifier

I have a question about preparing the dataset of positive samples for a cascaded classifier that will be used for object detection. As positive samples, I have been given 3 sets of images: a set of ...
2
votes
1answer
481 views

Which algorithms are usable for heatmaps and what are their pros and cons

This is a cross post from Stack Overflow, and DSP at Stackexchange since I cannot really decide which part of Stackexchange is most fitting. If this is the wrong place please tell me and I'll remove ...
1
vote
1answer
71 views

Job sites for applied/interdisciplinary mathematics related to computer science? [closed]

I'm looking for job sites in applied/interdisciplinary mathematics, more specially, say postdocs or higher positions in mathematics and medical imaging, mathematics and computer vision. I'm aware of ...