Questions tagged [image-processing]

In general, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame.

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what is the possible solution for the Intra-class variations poblems?

my poblem is that i have a database for human dorsal hand veins ,but with intra-class variations , so this problem have a large effect on my results when i need to do matching between my samples for ...
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How do I keep a value between known bounds in an open system?

I detect points in images with an algorithm. The only parameter is a threshold T that I can modify at each image. Such images are from a continuous video, so each ...
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Fast approximate optical flow / image shift

I need to detect how fast a camera is panning (either horizontal/vertical) to give a warning to the operator to slow down. The entire image is moving as a block, I don't need an actual direction (...
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Identify the correct spot to place a label

In the image shown below, I have a 2D data set where I have identified four clusters labeled [0,1,2,3]. I'm looking for an algorithm to place the labels in a ...
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How to remove stains from images?

I have this extremely distorted and stained image Is it possible to remove this stain ? Could image inpainting help ? Please help EDIT : Another image After applying anisotropic diffusion and ...
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Conversion between primary colours

Heads up, this is homework. Just a little stumped :) I have some arbitrary primaries, A, B, ...
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What image-processing techniques are ideal for this particular shift/scale invariant template matching?

A problem I had originally discussed here has evolved, and might have gotten a little simpler as I studied it in some more and attained new information. Bottom line, I would like to be able to detect ...
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Interpolation algorithms in computer graphics

I'm looking for an image-processing algorithm that uses interpolation (polynomial, spline, doesn't matter). I have to implement such algorithm to process a bitmap for my labs. It can't be image ...
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Could you describe the effects for varying different parameters of a canny edge detector?

Last couple of questions touched upon Canny edge detector What are the limitations of a Canny edge detector? and Best way of segmenting veins in leaves? The basic outline of the algorithm is as ...
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how to remove color of light source?

I have an image source emitting yellow light. Of course, when taking a picture with the light, the image has yellowness overall. How can I remove that color of light from the image? I have another ...
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What segmentation methods can be used for simple images?

As related to the project I am currently involved in, I have come to realize that one thing that might help is for me to 'segment' my image. To that end, I have shown a very simple example below. ...
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Finding radius r of the overlappable sphere(s) in 3D image

My current problem: I have an input 3D binary image (a 3D matrix that has only 0 and 1) that consists of random numbers of sphere with radius r. We do not know how many spheres are there in the ...
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Text recognition for Android app

I´d like to use some OCR algorithm (Image to Text) into an Android app (Java). I have previously used several algorithms but for a PC (Matlab) app. Which library or algorithm should I use? ...
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Opencv calcHist and calcBackProject in plain english

i've started experimenting with c++ and opencv because of i want to learn image processing. Now, my first exercise is to create a skin detector with calcHist and calcBackProject. But i don't ...
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What is the name of this color transformation?

This is a question regarding color transformation in images. I have this color transformation matrix I am using to convert an RGB image to a color space whose name I do not know: ...
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How can I detect elements of GUI using opencv?

Given a screenshot of an application, is there any way of finding GUI elements of that application using only opencv? (something like in the image) I tried to play with blending the image and other ...
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Implementing discrete Poisson equation wtih Neumann boundary condition

I am trying to reconstruct an image from gradients in an arbitrary shaped region of an image. I understand how to implement a discrete 2D poisson solution with Dirchlet boundary conditions. Using ...
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Is it possible to simplify the convolution integral if the functions are non-zero in disjoint areas? [duplicate]

Possible Duplicate: When convolving two functions that are constants in a region and 0 everywhere else, where does the integration start? I have a function $f(x,y)$ and $h(x,y)$. $f(x,y)$ has a ...
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Image Processing method for spiky selection

I have an input as a 3D binary image and the preferred output below: Input: Preferred Output: What image processing methods should I look for if I am to have only the spiky object(s) remain, just ...
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What would be the best solution to synchronize data from two inputs. (Camera and Acceleration sensors)

For a video stabilization project, a USB webcam (25 fps) and USB acceleration sensors are being used. the sensors gives a speed of approximately 50 samples/second. the derivative of the acceleration ...
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Topological skeleton matching techniques

What are the most common and best topological skeleton matching techniques? Suppose I have skeletonized object and corresponding 2D model of this object. What are the next steps to match pattern? ...
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How to measure the quality (or difference in quality) of different images?

I would like to measure the quality of a color image, possibly as a difference to another image, but if possible, on its own too. This question comes from the fact that we have a vision application, ...
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image feature extraction

We are given a set of grayscale image patches obtained from images after edge detection. Each patch is 10x10 pixels with intensity varying between 0 and 255 for each pixel. This set may contain a very ...
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Histogram Backprojection in OpenCV?

I am trying to get a rough estimate of a position of a hand through using backprojection on frames retrieved from a camera. I do not need perfect detection on the hand, but I can't really afford to ...
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one to many images matching in matlab?

i have database for 50 person ,it is 250 images (5 images/person) , i need to perform one to many matching between images for recognition persons. so , i divided the image as 2 parts (one for ...
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What methodology to use for discrimination of different (musical?) tones

I am trying to research and figure out how best to attack this problem. It straddles music processing, image processing, and signal processing, and so there are a myriad number of ways to look at it. ...
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I'm looking to do my senior capstone project in the field of medical tomography, what is a good book to get acquainted with the field?

I'm a junior currently pursuing a mathematics degree with aspirations toward medical school. I have a senior project I have my entire last year to devote time to, and I've decided that I want to ...
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Good language for computer vision?

I am trying to implement a content based image retrieval system but before I do so I would like to get an overview of some programming languages suitable for this task (having good libs and such). ...
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is it possible to matching b / w images without feature extraction steps? if possible which algorithm may be more suitable?

these are example of my image i have a 245 images similar to it ,i obtained these b/w images after preprocessing stage , i want to use them for recognition persons(not verification) in matlab. can i ...
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List of all available ARM+DSP processors for surveillance

I have come across TI's C6000/Integra. I want to know is there any other similar or better ARM+DSPs available. Specially for surveillance/vehicle number plate recognition etc. Having camera input at ...
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How to outline a defect in an image?

The images given below are a result of fruit defect detection algorithm i have made myself... Just wanted to know is there a way of outlining these defects? Original image 1: 1st Image: Original ...
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How do I remove all white pixels in a modified image which are not present in the original?

I have the following image and after thresholding it, I obtained this result: How can I remove all white pixels which do not belong to the original image? The desired output should look like this (...
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Contours chains matching techniques

I have chain contours representation: - classic Freeman chain - angle chain with distance (first: angle between neighbor points, second: distance between them) What are the best techniques to ...
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1answer
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Removing white pixels from a b/w image in MATLAB?

Consider this MATLAB code: mg=imread(........bmp'); level=graythresh(mg); x=im2bw(mg,level); figure,imshow(x); BW2 = bwperim(~x); figure,imshow(BW2); ...
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Blurring in anisotropic outputs

I am trying to produce ideal anisotropic diffusion outputs using the standard lena image. Using the first coefficient , the output is coming somewhat close to ideal ouput but when I increase the kappa ...
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Non-orthogonal basis which offers better energy compaction in image compression

I am aware of image-independent basis, i.e. DCT, and image-dependent basis, i.e. Karhunen–Loève, which are used in compacting energies for image compression. These bases are orthorgonal. Are there ...
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Anti-aliased boolean masks for integration of CCD images

(This question was already asked on Stack Overflow under the tags Matlab/Octave/Signal-processing/Image-processing, but I am reposting it here following the advice of one user that this site may be a ...
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Java - Convert Image to Binary (Two Colours/Black & White)

Is it possible to convert a .jpg image to binary using Java? I have asked a similar question on StackOverflow but thought that maybe this may be a good place to ask, too. I am currently able to ...
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Iris recognition using filters?

I am implementing an iris recognition system in matlab and have performed the following steps according to an algorithm proposed in a paper Initial image Median filtering For each row in the ...
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Which are the steps to extract contours/shapes from depth videos?

I am trying to create a histogram of the depth videos (converted to grayscale first) in order to apply a threshold to keep only highest values, and then do some dilation in order to extract contours. ...
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Are there any good “conceptual distances” for comparing two images?

I want to define some distances to use over an image, which I create. I think I need to define two different "distances". The first distance should be the most robustness preserving in compare to ...
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1answer
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Identify rectangles of different colors

How identify the presence or absence of regular stripes of different colors, but ranging from very very very very light pink to black inside of a scanned image (bitmap 200x200dpi 24-bit). Carry a few ...
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main direction in 2D map of data

It may be a very simple question. We would appreciate any comments, guide or complete solution. We prefer however incomplete solutions but novel practical ideas. - How to find the main direction of ...
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Open Source Implementation of 3D Thinning algorithm

I am looking for open source implementation of thinning algorithm in 3D. Thinning algorithm: Convert binary shapes to 1-pixel wide lines, without shortening it or breaking it apart. For example, ...
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1answer
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How to amplify regions with specific color in an image?

I want to amplify regions with a specified color in an image. For this purpose I have defined a simple function $B(x,y)=s_r(x,y) \cdot w_r + s_g(x,y) \cdot w_g + s_b(x,y) \cdot w_b$ which produces a ...
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Find a specific line in a picture

I want to find the line between color blue and color gray in the following picture: More exactly, the end points of that line. Is the Hough transform a choice? If yes how should I set up the picture ...
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How do I reconstruct text from an image using only morphological operations?

I want to reconstruct the text from the following image as best as possible. The tricky part is that I want to do it only using morphorogical operations on the image I tried using erosion, dilation, ...
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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 ...
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How to implement a gradient based Hough transform

I am trying to use the Hough transform for edge detection, and would like to use gradient images as the basis. What I have done so far, given the image I of size <...
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Detecting a fixed template image out of a semi-constant frame of video

There are a number of videos that I'm looking to process of different video games to detect various "states" in them. The first game that I am tackling is any edition of Super Street Fighter 4. In ...