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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11 views

Is there a way to access each individual segmented element?

I'm following this tutorial The goal is to be able to spit out either: a. the center of each labeled object b. all pixels associated with each labeled object in a way that I have an array of either ...
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3answers
66 views

What is the maximum dynamic range of an N bit signal?

In this presentation on slide 15 there is a corollary: Rule of thumb: the dark noise must be larger than 0.5 Corollary: With a N bit digital signal you can deliver no more*) than N+1 bit ...
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16 views

How to calculate the freedom of projection matrix?

I learned projection matrix from textbook. It says that the 9th is redundant, so it has 8 freedom. But I can not know the reason clearly. Following the equations. I can not understand why i does ...
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0answers
29 views

Underwater Acoustic OFDM [on hold]

What are the steps involved in making an Underwater Acoustic receiver In matlab Using OFDM? I want to send a picture through an underwater tank and receive it at the other end, using OFDM. Can ...
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0answers
23 views

Optimal way for curve detection

I am totally new to image recognition and image analysis and have a project concerning detecting a smooth curve on a uniform background (white/black/any color) and then be able to follow this curve ...
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0answers
10 views

Where can I find annotated databases of faces with profile views?

I'm working on a project that uses AAMs (Active Appearance Models). I'd like to have an AAM with profile view. Is is possible to get free annotated images of faces in a profile view?
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0answers
13 views

linear contrast stretching based on minimum and maximum calculation from image histogram

I'm studying Gonzalez image processing book and under the topic linear contrast stretching based on minimum and maximum calculation from image histogram has been ...
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0answers
8 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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0answers
23 views

Animal Detection and Recognition

I am working on a project deer detection and recognition. How i will proceed through this project using neural networks in java/.Net using Encog. My task is to detect a deer and it's antler, if it ...
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0answers
21 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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0answers
21 views

Intelligent feature vector for an image classification problem

I am a person who loves to learn machine learning from an application point of view. My Objective : To learn machine learning by doing examples in MATLAB or Python like environments. The priority ...
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1answer
35 views

Histogram and binary image in opencv? [on hold]

I would like to compute how many zeros and ones (e.i. 255) in a binary image. The following code to generate a binary image by using Matlab. ...
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16 views

Multi Scale Gradient Structure Tensor

I have implemented the Gradient Structure Tensor for Coherence computation. But the issues of Scale-Space are not giving optimal results. Is there any technique targeted for Multi-Scale GST, so that ...
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34 views

Spectral entropy

I have two signals taken from accelerometers different sides of the body. I want to perform a calculation for spectral entropy as a means for comparing the two signals . I have done my calculations in ...
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0answers
28 views

Realtime image-stitching using a CMOS camera array

I am very new to DSP so please excuse any brevity... I have to design a 4x4 CMOS camera array and stitch the images together for further processing... I have tried doing that with opencv but the ...
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1answer
29 views

Effect of averaging an image [on hold]

I want to know what is the effect of averaging an image.In which application it is useful?Thanks!
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2answers
22 views

Need samples of big endian encoded tifs [on hold]

Folks I've written a small utility that extracts some (and only some) header information from Tifs. To test it fully I need some Big Endian Tifs, but I cant find any, and I can't find anything to ...
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0answers
23 views

using frequency of image to update it

I am using c# in a desktop application. If the image - which comes from an ip camera changes from the previous frame then I upload the image in bytes to my web server. I have found some images are ...
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2answers
64 views

Otsu's method problem?

I have a problem with Otsu's method. I would like to implement histogram to compute how many ones' and zeros'. For Otsu's method, I have a code from a book and it is running without problem. This is ...
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1answer
47 views

Best method to segment a given image

I have one image. I want to segment it by simple approach. Could you suggest to me the best method to segment it? I think one of them is gradient or FCM. But I am not sure. Please see my given image ...
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2answers
20 views

Tracking using color

I am working on tracking an object in a video by using its color. what i did is that i have converted the color of a selected object into LAB color space since it is a uniform color space. and then in ...
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0answers
25 views

how to calculate feature points in SIFT?

i wanna know how to calculate key points? im doing it in matlab. when i select 3 DOG(differnce of gaussian) blured image and compared each pixels in the middle image with 26 neighbourhood(including 9 ...
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0answers
14 views

Triangular Kernel Estimator vs other kernels

For image processing are often used different Kernels for the extraction of keypoint descriptors, is not clear for me how triangle-shaped responses are more relevant than a gaussian response, is this ...
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2answers
54 views

2D Deconvolution in matlab

I am trying to solve the following equation for h (an [MxM matrix]): $$ k[\tau_1,\tau_2]=\sum_{i_1=0}^M \sum_{i_2=0}^M h[i_1,i_2]x[\tau_1-i_1]x[\tau_2-i_2] $$ I have k, which is a 2D [MxM] symmetric ...
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2answers
89 views

Options to enhance a poor image

I have a C# desktop application. I am using EMGU as a wrapper for OpenCV. I am receiving images in JPEG format that were originally taken by an analogue camera. The quality of the image is poor ...
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1answer
33 views

2D version of Shift Theorem

What is the 2D version of Shift Theorem?
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3answers
71 views

What is benefit when convert signed 16 bit to unsigned 8 bit in medical image?

I have an image with its type is 16 bit signed. I see some paper, the author often convert it to unsigned 8 bit. But they did not explain why they do it. Could you explain what is benefit of this ...
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1answer
51 views

Entropy/frequency of a natural image

I have a C# desktop application. I am using a wrapper to OpenCV which is EMGU. I am just performing a basic motion detection operation. I am using component labelling and 2 frames differencing to ...
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3answers
63 views

Best way to remove unwanted region from image

I am finding the techniques to remove unwanted regions (small dots) from image. I have an image that includes object and some unwanted region (small dots- see first image). I want to remove it. Hence, ...
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1answer
64 views

Image Noise Detection Using MATLAB

I want to implement the following algorithm. Let I denote noisy image and for each pixel of I is represented by I(x,y). A Sliding window of size 3X3 centered at I(x, y) is defined. At first ...
3
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0answers
30 views

Interpolating on the borders of differently-resolved images

I'm creating a three-dimensional model of the earth based on SRTM height data. The data set is pretty huge, so only a small fraction of the data is available at any given time. The height data is ...
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26 views

reducing chroma of image on client and reconstructing on server

I have a C# desktop application. I am using Emgu wrapper to openCV. My objective is to upload images in the most efficient way I can. I have hit upon the idea of loading an image (jpeg) into memory ...
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1answer
79 views

Entropy of an image

If I want to measure entropy of an image how should I do it? My aim is to ignore things like tree leaves moving in the wind with my C# desktop application. I know matlab has this functionality but I ...
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0answers
35 views

Sharpening an image using emgu

I have c# desktop application and I am using emgu framework as a wrapper for OpenCV. I am trying to sharpen an image because the input images are not great. I tired a technique I found via searches ...
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0answers
13 views

question about the frequency of Gabor filters

The Fourier transform of 2D Gabor filters is shown below: F is the radial frequency of the Gabor functions. Another parameter Fm is denoted as highest central frequency. Fr is the constant ...
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1answer
63 views

How to make filters?

I am trying to make filters like sepia filter in my app like other photo editing applications , till now I don't have any idea about it , Can any one help me out ...
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0answers
98 views

Malaysia Flight 370 Image Processing

I wish that all those people on that flight were with us, and maybe they still are, as I like to think they are on an island somewhere waiting to us to find them ... however, it does not look good... ...
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2answers
87 views

Improve contrast when image has a flood of white balancing

I have an image taken a night time. I apply _EqualizeHist to it. But the result is a high level of whiteness running through the image. This is the image: I had asked this question in a slightly ...
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0answers
47 views

Why does the inverse fourier transform of a lowpass filter have complex components in matlab?

I am quite confused whether the following numerical differences i find are just severe round off errors made by matlab, or something i am doing wrong. The following happened when trying to see what a ...
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73 views

Image Processing/Analysis for Eye blink detection

I am working on a eye blink detection project in Matlab. By this moment I have been successfully extracted the images of pupil of eye from the real time video captured via a web cam. But I am stuck ...
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0answers
47 views

motion detection within a poor contrast image

I have a C# desktop application. Its purpose is to detect motion changes between consecutive frames. Currently I am using the excellent Emgu wrapper to OpenCV. Now, I know this question may seem ...
2
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0answers
15 views

Meaning of tight frame in the context of texture synthesis

I am currently reading "A parametric texture model based on joint statistics of complex wavelet coefficients", by Portilla and Simoncelli. In this article, they use the "steerable pyramid" to ...
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1answer
19 views

What are the Segmentation algorithms that can be used to process Satellite images (obtained from Google Earth) to segment forest and barren areas?

I have tried Region based Segmentation - through Seed Growing, Watershed algorithm, and Graphcut algorithm, but none have been successful so far. I am using MATLAB.
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27 views

Dice Similarity coefficient for 3D image?

I am want to calculate Dice Similarity Coefficient (DSC) for 3D image. I done it for 2D. But I don't know how to apply it or change for 3D. Could you help me to find the way to calculate DSC for 3D ...
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1answer
18 views

Is there any difference between the 2D continuous and discrete Gabor filter when it comes to MATLAB implementation

I want to know the difference between the 2D continuous and discrete Gabor filter when it comes to Matlab implementation. I found many files related to 2D Gabor filter on Mathworks File Exchange but I ...
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2answers
37 views

Complex numbers in a frequency domain of a 2D image [duplicate]

I am try to grasp the idea of frequency domain for images. I think get the basics, but now I've stuck with a question that I can't find appropriate answer anywhere. How are frequency domain and ...
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2answers
58 views

Error: Image Noise detection in MATLAB

I am getting error while implementing a simple idea for noise detection in an image. Let I denote noisy image and for each pixel of I is represented by I(x,y). A Sliding window of size 3X3 ...
1
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2answers
84 views

How to detect, using matlab, the center of the biggest circle?

The goal is to preprocess an image in a way that outside the circle isn't in the region-of-interest so set its value to 0 (black). That way the followed step of segmentation will be easier to analyze ...
0
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1answer
19 views

How to set covariance for Bivariate Logistic Distribution

This is the logistic distribution of single random variable (taken from Wikipedia). x = random variable mu = mean of all random variables s = variance. Now, I want to do a Bivariate logistic ...
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1answer
27 views

How to undo the quantization step in DCT?

How can I do point by point multiplication of the quantized DCT coefficients with the quantization matrix before computing the inverse DCT for each block? I want to modify the reconstruction algorithm ...