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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19 views

Error in Visual Studio while trying to load image using OpenCV [on hold]

I was trying to load an Image in Visual Studio 2013 (on 32-bit Windows machine), using OpenCV 2.4.10, but came across an error as: "Unable to start program 'C:\\Documents\Visual Studio ...
0
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9 views

What images are better when training tesseract-ocr

I have a project that requires different language support and optical character recognition. Like many others, I just can't figure out how to train tesseract. Incredibly low amount of documentation, ...
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20 views

Does the enlarged photo benefit from shrinking it?

Take a look at the following diagrams: The original picture: The upscaled (2x, bilinear) picture: In both cases the first item in first row is the input image. There is it's 2d fft next to it. ...
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1answer
24 views

Upscaling detection approach

I'm trying to implement a solution that would, to some extent, evaluate a picture telling what are the chances that it was upscaled from the smaller image. My approach is as follows: Take a picture ...
0
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0answers
7 views

Time Lapse Video Analysis: Changes in Light Quality

I am working with a set of hundreds of simultaneously recorded time-lapse videos, and I want to be able to quantitatively determine which frames show the transition from night to dawn and day to dusk ...
2
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1answer
48 views

How to analyse Phase spectrum of 2D signals?

I am beginner in image processing. When I applied Fourier transform on two images say Lena and Cameraman etc., I obtained magnitude and phase spectrum for each one. I want to concentrate on phase ...
0
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1answer
37 views

Circle detection opencv

I Would like an explanation of the parameters for opencv's HoughCircles function. I'm new to image processing in general and I have recently started using opencv. ...
1
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1answer
29 views

What preprocessing technique can help me to filter the background text noises using matlab…the image is shown below?

Can anyone help me to improve the degradation of the following image....i am working on OCR system in Amharic language and what is the best image filtering technique that can help me to separate ...
2
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1answer
57 views

Is image reconstruction possible using its magnitude only?

Let us take any image like Lena or cameraman. I know that when Fourier transform is applied on image,spatially global features like amplitude and phase are obtained locally. My question is whether it ...
0
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0answers
9 views

How to programatically perform image segmentation in real-time

I am currently trying to segment ultrasound images of blood vessels (video frames), such as the one directly below. Using a simple binary filter on the saturation channel (code below), I can get a ...
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1answer
44 views

Multi-image denoising

I have two signals Sa and Sb, both affected by the same noise. I don't know how much noise is mixed into each one, and the signal+noise is transformed using some (unknown) nonlinear function before I ...
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2answers
54 views

Best Car Recognition Algorithm

Could anyone suggest the best algorithm for a real-time Car recognition (say in a parking space)? I am planning to implement the same on FPGA as well. Kindly suggest. Thank you.
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17 views

Is it possible to auto compute for the optimal value of Lagrangian multiplier?

Consider the cost function $f(X,\lambda) = \|AX-b\|_2^2 + \alpha \|LX\|_2^2$ $A:$Measurement matrix($R_{m\times n}$,$m \ll n$), $b:$observation vector($R_m$), $L:$Laplacian operator($R_{n \times ...
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0answers
12 views

How to use Kernel of Pattern recognition in c++? [closed]

I am having a code for Sparse representation classification for Face recognition in c++. I wanted to use Kernel trick to perform Kernel sparse representation classification. Please suggest some ...
2
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2answers
56 views

How to detect letters in an image?

I have a project that requires detecting and processing letters in a given input image. I am also new to subject of image processing. There are lots of subsubjects in image processing. I believe I ...
0
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0answers
19 views

Amplitudes and phases of transform of an image

I have recorded an image of a large macromolecule and after several types of image analysis, have obtained a rotationally averaged image, that is not quite perfect, but appears to show 6-fold ...
0
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1answer
57 views

MATLAB: Decimation image

I'm trying to decimate given picture Vertically. Horizontally. Horizontally + Vertically. I know that I should use low-pass filter* and then downsample** it not to see any aliasing in image. To ...
0
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0answers
35 views

Difficulties with derivative of convolutions in Fourier domain

I am trying to solve a minimization problem in the DFT domain. I have a formula where both dot products and convolutions are involved. Capital letters are the DFT of 2d images, the overline denotes ...
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0answers
18 views

How does Arbib's clustering method work?

Recently in Image Processing I've been studying image clustering (or segmentation) methods and one of them is Arbib's. I understand the main idea behind it from which you start with one cluster with ...
0
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0answers
10 views

Need to order a set of colors to build a feature vector

I am working on Computer Vision task of object classification with python and OpenCV. Currently I am extracting some characteristic colors of an image using K-means clustering on all the pixel to ...
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0answers
19 views

Equivalent of the Shepp-Logan phantom for video denoising

The Shepp-Logan phantom is a standard test image used in reconstruction algorithms as well as image denoising. Does an equivalent image sequence exist for testing video denoising algorithms? I know ...
0
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0answers
32 views

Non-maxima suppression of gradient image

I'm new to image processing, However I was trying to learn how to detect edges using Sobel filter I had obtained the image gradient in both X and Y directions successfully using Emgu built in ...
0
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0answers
18 views

What are most often used and effective algorithm to compensate the imaging depth

I hope the picture below says everything: Assume the center of camera lens is aligned with the centroid of target. The left picture shows the ideal positioning, i.e., the target is placed at the ...
1
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1answer
21 views

How to apply the provided wave transforms on an image

I want to implement one of the following mappings in MATLAB and verify its performance on an image, but I couldn't. Please help me with the implementation
0
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1answer
27 views

How to implement Fourier Descriptor of an image?

I want to implement Fourier Descriptor of an object. I have read link. However, I have some questions about normalizing Fourier Descriptor. First, if I want to normalize the position of the starting ...
2
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2answers
193 views

Segmentation of overlapping noisy parallelograms in a binary image

Edited. Previously this question was named "Segmentation of overlapping pulses in a binary spectrogram" and it was stated in slightly different way. I'm apologise to those users, who were affected by ...
0
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0answers
29 views

How can I make the background color white for this Grab-cut algorithm written in Python?

I am new to Image Processing and am using Grab cut algorithm to extract the foreground objects from images as a part of my project. Below is the code written in python to do the same. The problem is ...
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0answers
10 views

Skeletonize using imagej in java

I`m trying to get skeleton of an an Binary image in java. I used Imagej library in Java whit this code: new ByteProcessor(Image).skeletonize(); Image : ...
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1answer
67 views

How can I get back these two signals?

Let's imagine that I am using a camera and that I take pictures. I want to estimate pixel-wise gain from that camera however I cannot get a light distribution more even than this: Now, let's ...
0
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0answers
25 views

Saddle points, Nodes and Edges definitions

I am working on some algorithm implementation, however being new to image processing, I have some questions about some of the definitions used. UPDATE: for those asking for more information, this is ...
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1answer
45 views

Ridge finding in noisy 2D image

I'm using MATLAB, and have experience with it but not with this kind of problem. I'm trying to identify white lines in noisy 2D images such as the one below. I can separate the brighter ones just by ...
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0answers
27 views

Distinguish between 2D and 3D objects according to depth

I'm trying to distinguish by code between a real 3D object and its picture - a 2D object, based on depth information. However the picture (= the 2D image) might be captured from noisy background, so I ...
0
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0answers
10 views

Measuring contrast of a jpeg

I am knew to image processing. I am using Emgu C# I want to somehow measure the contrast of an image. It would be enough for my purposes to say ImageA has more contrast than ImageB. I have spent ...
0
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2answers
38 views

why wavelet coefficients are zeros after decomposition

I am learning wavelet theory for image processing. To understand the theory, I write one Matlab program to decompose one black-white image. The program is as follows ...
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0answers
38 views

How to implement HOG with trilinear interpolation by Matlab?

I am studying HOG. I have find the code code1 and code2 about HOG. However, both of them don't implement trilinear interpolation. I have also read some websites, including web1 and web2. I still don't ...
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1answer
44 views

How to interpret this!! I am confused! [closed]

img = rgb2gray(imread('lena.bmp')); imgFirstHalf = img(:,1:2:end); imgSecondHalf= img(:,2:2:end); implay(cat(3,imgFirstHalf,imgSecondHalf)) Now the question ...
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0answers
29 views

What is the best book on Digital Signal processing for math majors? [duplicate]

I am a math major and have knowledge of Calculus, Real and Complex Analysis,PDEs and probability theory. I would like to get started with DSP and need a book suitable for math majors. Please give your ...
2
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1answer
44 views

How to remove text region in a document image? or extract image from a document image

Given a document image (i.e. newspaper), how to extract photos in it or remove text region? I think traditional OCR methods may not be suitable here, as I don't need to recognize the text, and OCR is ...
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0answers
22 views

How do I deal with occlusion, warping, or perspective distortion for object detection

I am using SIFT features for detecting logos in clothes. SIFT is quite powerful, as it is scale invariant, but how do I deal with the problem of occlusion and warping? More specifically, the logos in ...
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0answers
17 views

Extract graph data from map image

I have a map (in image format) describing the power grid of a continent. Power plants have flags next to them, indicating their type (hydro, gas, oil, etc.). The power lines have a color indicating ...
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1answer
29 views

How to segment object when it has similar histogram with background

I am working in image segmentation and I would like to ask you something about my problem. I have a image such as bellow. I want to segment leopard from background. However, intensity information is ...
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2answers
78 views

Can wavelets be used for complex texture discrimination?

I've recently been studying wavelet analysis with a view to differentiating certain areas of texture images where the texture differs from the background pattern (which is quite random); for example a ...
0
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0answers
23 views

Creating a texture image from existing image

I have some unusual question. I have searched online and couldn't find something similar to what I want to achieve. I have an image, and I want to create a new image from it (in the same size), so ...
0
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0answers
31 views

Small Font Arabic OCR character segmentation

I'm working on an Arabic OCR , it already works on font sizes 20, 30, 40 and 60 pixel height, currently I am trying to make it work on 10 pixel height, as I mentioned here before I tried first to ...
0
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0answers
16 views

What are the main roles of leverage scores and low rank approximation in computer vision applications?

I'm just starting to learn about the field of computer vision. I would like to hear from experienced SE users regarding the following questions 1) I know that computer vision is driven by numerical ...
2
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1answer
103 views

How to tell whether an image has a low gamma (Finding out imaging system tone map)

I am using Emgu C#. I acquire images from my cameras. I know when there is no saturation (ie a grey-tone image) by looking at the average hue channel of the image. If zero then pretty sure picture ...
0
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0answers
12 views

CT image segmentation

I have two CT images reconstructed from a Shepp-Logan simulation, but they suffer leakage artifacts. Although they are distorted, the two images contain all the structure information. I was ...
0
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3answers
21 views

Histogram Equalization - mapping a certain portion of pixels to pure black and white

How can I make sure to map, for example, 7% of the pixels to pure black (0) and pure white (255) in a grayscale image?
1
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2answers
65 views

Is there a better Fourier Transform-based algorithm to use in Image recognition

I have been trying to use the Fourier transform in recognizing images of the same size 200x400. I have tried many different ways to do that such as: Performing the Fourier on the full image and ...
1
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1answer
59 views

What is the ideal type of barcode for paper tickets?

I can use the following type of barcodes in my project: Code 39 Code 128 QR Code Data Matrix PDF-417 They will be printed with standard office printers and with boca printers. It should also be ...