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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Image Segmentation - Berkeley Dataset

I've been given an image from Berkeley dataset to segmentate. I am an undergrad student and so far I threw everything i know to this thing. But the colors are extremely close. I tried; Clustering ...
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13 views

What are the keywords to find an algorithm that detects embossed text from a 3d model?

Currently I am doing an acadmic research about an idea which came into my mind lately. I have a 3d model and I want to extract embossed text .. anyone knows any papers? or if it is already proposed? ...
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5 views

What is the syntax of qt's convertToFormat() function?

I am new to using qt's qimage class, and I am not being able to find out how to convert a given image to Grayscale. Syntax is shown in the website, but I dont know ...
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1answer
34 views

applying convolution theorem swaps quadrants

For educational purposes I implemented the DFT and inverse DFT for images using OpenCV. Applying the DFT to an image and taking the inverse DFT of the spectrum yields the original image, so this ...
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14 views

How do i detect if an image has a gradient or not?

I have coloured images, some may be just clipart, some may be artwork, both could be with or without gradients. Before i run a colour counting algorithm on them, i want to detect if the image has ...
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25 views

Why Normalized Cross Correlation Score of different templates is high?

I am using OpenCv's built in template matching function to search for an object in image. I am using Normalized Cross Correlation Method.The function is returning a value which I think indication of ...
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15 views

Analytical expression for convolution of two 2D DFTs

I am trying to do an image analysis problem on some images, and I want to calculate some things in the frequency domain which are giving me problems. Say I have an (discrete) image $I(x,y)$ of size ...
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8 views

SRAD code in matlab it doesn't work [closed]

i just applied the SRAD code in matlab and i get error in line 430 ...
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2answers
40 views

convolution matrix for image scaling

Is there any way how to compute convolution matrix for Nearest Neighbor (bicubic, bilinear) image scaling (upscale/downscale)?
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14 views

Signal to noise ratio (SNR) measurement using ImageJ

I need to use the image J for my final year project. Could you please recommend me on how to measure the SNR by using this software? If you don't mine, i need the steps as i am still new in learning ...
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17 views

Puzzled video:: medical imaging shadow

Any thoughts about this video and the algorithm behind it? https://www.youtube.com/watch?v=9X4kEOYcZ2s Is there another source of light, such as green bulb? Is it replicable? shadow
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15 views

SIFT Problem with producing first layer of first octave

[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 times. In Section 3.3, there is a ...
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32 views

How to find the corner of a whale fin?

I have got the images of whales and I extract the fin from the whale and then apply an edge detection algorithm which gives me a 2 dimensional vector with the edge values. I can plot this vector to ...
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1answer
18 views

Tracking a Predefined Curve in a Series of Images

I have a series of images. I want to be able to draw a curve on the image and track the curve in the series. For example, in the figure below, the left image illustrates the original image at time ...
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18 views

Convolution / Correlation correct implementation in java

I have a java programm which is manipulating an RGB picture which comes in a 3dimensional matrix. I tried to implement an apply Convolution and an apply Correlation function, which applies a kernel ...
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1answer
23 views

Medical image dataset

I am doing some project on medical image processing and I need some uncompressed medical images especially magnetic resonance angiography, vessel and so on. I have searched a lot but most of the ...
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19 views

$ICA used for feature reduction on images

I am working on a semestral project that consists of different parts in image segmentation. I am developing part with transformation of image features. As reference I have PCA for dimensionality ...
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1answer
23 views

Image processing to detect water diseases

Is there any way to detect water diseases using image processing ? and is there any way to develop it in android or in matlab thank you ?
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1answer
24 views

Image Projection with SIFT

Recently, I am thinking about a problem regarding image projection. I have a larger picture as bellow. I want to find the transformation matrix, x'=Hx. When the above image pass the transformation ...
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1answer
49 views

Why do eigenvectors specify the direction of fastest and slowest changes in the image

I'm reading Szeliski's Computer Vision:Algorithms and Applications. On page 212-213, corner detector is discussed. I can understand upto equation 4.8. From then on, I don't understand how come ...
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2answers
21 views

Changing camera and image properties to calibrate a camera

Is it OK to calibrate a camera using effects and filters such as increasing contrast and brightness etc. to improve the detection of corners of a chessboard? Even if the used mode for detecting the ...
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8 views

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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18 views

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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21 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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69 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
28 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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35 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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18 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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2answers
95 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
56 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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48 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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18 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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30 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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16 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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19 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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28 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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17 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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78 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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23 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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40 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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45 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
50 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
59 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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35 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
349 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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71 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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41 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 ...