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 difference between Harris Corner Detection and SUSAN Corner Detection?

What is the difference between Harris Corner Detection and SUSAN Corner Detection
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Creating graph from edges, shape detection

I am writing a shape detection program (for example, I make a triangle with fingers and algorithm finds it). My idea was to detect edges, "straighten" them, create graph from all the segments and ...
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8 views

SIFT- a problem about frequency of sampling for SIFT

[1]Distinctive Image Features from Scale-Invariant Keypoints D. G. Lowe Int. Journal of Computer Vision 60(2) (2004), pp. 91--110' I have read [1] for several days. Besides, I have ...
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20 views

What would happen if I perform histogram equalisation on average RGB

In Image signal processing, I'm trying to figure out what would be the consequences of performing a histogram equalisation on the average of the 3 channels (R,G,B). I'm trying to conclude some ...
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2answers
43 views

Detecting changes between two similar images

I have the following problem: I need to detect changes between two more or less similar image. In that case, I want to detect the missing parts. Lets assume that the displacement is no more that ...
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1answer
17 views

Decompose an image into better compressible components

Our team develops an application that, in some feature, connects to a scanner (via TWAIN or WIA) and scans a document, and makes a PDF file out of it. The application is mostly used to process mail or ...
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28 views

Image processing: Importance of phase

I was doing some experiment on image processing. I wanted to explore the importance of phase and Magnitude. I followed the following approach: Take 2 image of same dimension. Apply Fourier ...
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16 views

Bit Plane Complexity Segmentation (BPCS)

I am working in digital image steganography. Although I am novice but implemented some of LSB substitution based steganographic methods. Now want to implement Bit Plane Complexity Segmentation ...
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Structured light 3D imaging

i am currently working on structured light 3-D imaging, i have read no of journal papers but still i am not getting practical approach of the subject. Especially how to use triangulation principle, I ...
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2answers
59 views

Head detection using HOG and SVM

I am currently trying to detect heads in a sequence of real-footage images and am using HOG feature descriptor and SVM as classifier. Currently I am using Dalal's HOG implementation code in MATLAB ...
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1answer
41 views

what method for thresholding?

I want to do one threshold method on high pass components of a wavelet frame decomposition approch,for edge detection in image. I have 14 high pass components. for thresholding, I need keep the ...
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43 views

Sobel Vs Gaussian Derivative

What would be the most significant difference when using either a sobel filter or a gaussian-derivative filter, apart from the obvious difference of the size of the 2 filters?
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15 views

Need good resources to study 'Speeded up Robust features'

My current project is about Speeded up Robust features(SURF). I am a beginner in Image processing and new to this concept. Even though i found a lot of information on Internet, i am not able to find ...
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Taking a special image derivative using convolution

Could someone help me with the question posted here, which I posted in stackoverflow. I should have posted the question here in the signal processing.
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26 views

Looking to understand line artifacts in “overscanned” image

Essentially I'm looking for an explanation how the second image results from a capture of the original. Possibly you've seen something like this before and you can tell just from looking at the result ...
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14 views

how to get segmented OPTIC DISC from retinal image?

i have been segmented some image of retina. but the result is not good as i hope. for one image i can get good segmentation, like this image my code is from some reference in internet, in below i ...
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18 views

How do I remove the skin reflection from an ultrasound image?

I am trying to segment the fetal part from an ultrasound image. Most of the algorithms I have tried include the uterus skin reflection along with my region of interest. Is there a pre-processing ...
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8 views

Registering ensembles of images

I'm pretty new to image processing and have run into a bit of a problem with correcting experimentally-caused drifts in my images. In essence, I have a 2D matrix of images, where each image is ...
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What is the matrix representation of Radon transform?

Just as the title, my question is what is the matrix representation of Radon transform (Radon projection matrix)? I want to have an exact matrix for the Radon transformation. (I want to implement ...
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1answer
50 views

Can imaging hot object damage sensor?

I want to acquire images of hot object (melted metal - temperature 880 Celsius degrees). Distance is about 1,5 m. Can it damage sensor or other components like shutter curtains? I have read similar ...
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26 views

Reversing the radial blur effect

From Photoshop documentation: Radial Blur simulates the blur of a zooming or rotating camera to produce a soft blur. Choose Spin to blur along concentric circular lines, and then specify a degree ...
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15 views

What does decorrelation mean in terms of image compression

I have come across the term decorrelation, the "source encoding" performed on an input image while doing compression in JPEG must have "decorrelation" property, why? What does that mean?
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49 views

Image super resolution algorithm in Matlab

I'm trying to implement a simple Image super resolution algorithm (DWT-Based Resolution Enhancement ) in the following paper http://www.ripublication.com/aeee/52_pp%20%20%20405-412.pdf I tried to ...
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16 views

Motion Blur Filter

I want to implement Motion Blur Filter in C# using Emgu CV, what is the correct way to do this in fourier domain. I am currently stuck at how to perform multiply of Motion Blur filter and my Complex ...
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29 views

Fingerprint minutiae matching

I am working in a fingerprint recognition project using C code running on embedded system. After processing the fingerprint image, I have the minutiae now. I tried to matching two sets of minutiae by ...
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38 views

FFT signatures of QR codes

QR codes have three finder patterns at the edges (See image here) These patterns are inserted to enhance the detection of location of the code on a comparatively larger image. They produce some ...
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2answers
47 views

How to get started in image processing

I want to start studying image processing and need some tutorials for beginners. I am not bad at Mathematics and good when it comes to programming. I want to use the ...
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1answer
49 views

Noise in Digital image

in Digital Image Processing restoration ,from my understanding after reading articles , it's seems that the noise must be dominant in the histogram of the image , which is make it possible , to get ...
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32 views

Polygon Segmentation technique

I am working on Automated GUI components Segmentation problem. My Images are very simple as it has GUI components such as Buttons, text box and other polygons as you can see in the diagram (a). ...
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1answer
194 views

Matlab Neural Network toolbox

Is there any way to use as single input an image (256x256 pixels) and get output of single value using Matlab neural network toolbox
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68 views

Are discrete wavelet transform based statistical features invariant to rotation/translation/scale?

I'm reading a paper where image classification is done. Their approach is to use the discrete wavelet transform with bi-orthogonal wavelets of degree 3.5 and decomposition of level 3 on images. Based ...
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21 views

Some questions about the cube map representation

I am reading a text about cube map representation, but it seems I am confused. How the cube map representation can be used to detect lines using $xn_x+yn_y-d=0$? (we can ignore the polarity of lines.) ...
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29 views

What equation describes black alpha on a white image?

What equation best describes the alpha content of a black colored pixel applied to a white pixel when measuring the resulting pixel intensity? For instance given a white pixel: argb : 255, 255, ...
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31 views

Image enhancement algorithms for adjusting shadow, exposure, contrast etc

For those who have either used Picasa/Photoshop, they would see different image enhancement options such as: Change exposure Change shadow Change highlights Change vibrance I have searched online ...
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25 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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1answer
37 views

PSNR of two images of different size in matlab

I performed bicubic interpolation on a 256*256 image(img) dest = interp2(img,'bicubic') and i got a 511 * 511 image.I want to compute PSNR of a 512 * 512 ...
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36 views

Why doesn't JPEG use 1D DCT for image compression?

I know that JPEG uses 2D dct and splits the images in 8x8 blocks. Why doesn't it simply split the image in one-dimensional vectors in $\mathbb{R}^{64}$? Wouldn't it simplify the math? My guess is that ...
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33 views

Laplacian Operator with and without diagonal direction

This is a general question on the laplacian operator, which has two different versions. The first version is : \begin{matrix} 0 & 1 & 0 \\ 1 & -4 & 1 \\ 0 & 1 & 0 ...
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29 views

Size obtained by applying Linear convolution

We know that applying a filter on an image is called correlation or convolution depending on the filter angle. In Gonzalez I have read that we can apply linear convolution on an image. Here I have a ...
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6 views

What does non-parametric sampling mean in Texture Synthesis?

can I get a simple explanation of what non-parametric sampling mean in the area of texture synthesis? I can't get a relevant explanation of it. For example, the paper by Heeger and Bergen (1995) is ...
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1answer
26 views

A question about image compression with SVD - MATLAB

I have to compress an image by using svd. I did a few things but all of them produced gray image. However, Output must be rgb. How can i compress an image without changing its original format?
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138 views

[2D fourier transform]: Most people can't explain this

I am confuse of 2d magnitude plot of the spectrum frequency. So we have 2 images, the first one is shown at the top, and the expand version of the white box is shown at the second row. For the ...
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1answer
92 views

Inverse fourier transform by using a random phase and an original magnitude (matlab)

I want a image. Firstly I want to do fourier transform and get the magnitude and phase information. And then make a new random phase, finally use the changed random phase and original magnitude to ...
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27 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
21 views

Smooth X,Y,Z data with discontinuous, artificial jumps

I have some data $(X,Y,Z)$, which is a set of measurements $Z$ over a $2D$ space $X$,$Y$. The $Z$ data on this space is continuous except for some discontinuous jumps in certain domains of $X$,$Y$ ...
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2answers
75 views

how to detect corner in a digital image using MATLAB? [closed]

I am designing an algorithm for image processing. I am using MATLAB for the processing of the images(video). How I can detect the position of the corners in the image?
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1answer
48 views

Computer Vision / Speech Recognition

I am not sure if the question is off topic but I need some input before I can finalize anything. Actually to do my higher studies (in research) I wanted to make sure that I land my career in Digital ...
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1answer
50 views

Beginner's Books [duplicate]

I come from a background of computer science and I got interested in image processing but it requires a lot of signal processing, so could someone provide me a good beginner's book, that maybe first ...
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21 views

watermark embedding using 2d arrays

I have LL2 in a 2D array.(extracted after a 2-level DWT). And watermark W1 also in a 2D array.(a binary image, which only contains 0s and 255s). I need help regarding embedding the W1 in LL2 according ...
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32 views

Frequency of the wave in frequency domain

If we have a 1-dimensional wave in time domain, it can be represented in frequency domain with x axis indicating the frequency of the wave and y axis indicating amplitude/magnitude of the wave. But ...