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Questions tagged [image-processing]

Anything related to digital image processing, i.e. the theory and the techniques used to extract or manipulate information from digital images.

Image Processing involves any kind of signal processing in which the input is an image. The output can also be an image, or it can be information relative to the input image. Most image processing techniques involve treating the image as a two-dimensional array and applying standard signal processing techniques to it. Though optical and analog image processing are both well defined in the space of image processing, the tag image-processing in SO solely refers to digital image processing.

A good start on the field is having a look at the next links:

For an in-depth collection of explanations of a number of image processing topics, have a look at CVonline.

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How to auto crop an image white border in Java?

What's the easiest way to auto crop the white border out of an image in java? Thanks in advance...
rreyes1979
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How to rotate a video with OpenCV

How do you rotate all frames in a video stream using OpenCV? I tried using the code provided in a similar question, but it doesn't seem to work with the Iplimage image object returned cv.RetrieveFrame. This is the code I currently have: import cv,…
Cerin
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How to determine which aspect ratios are closest

Given a rectangular shape S, with aspect ratio sx/sy, and two other rectangular shapes A (with aspect ratio ax/ay) and B (with aspect ratio bx/by) how can I find out which of shape A or B has the closest aspect ratio to S? The shapes' sizes are…
Martin Wilson
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bandpass butterworth filter implementation in C++

I am implementing an image analysis algorithm using openCV and c++, but I found out openCV doesnt have any function for Butterworth Bandpass filter officially. in my project I have to pass a time series of pixels into the Butterworth 5 order filter…
user261002
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OpenCv 2.3 C - How to isolate object inside image

i have an image like: i want to remove the black rows and cols round the number. So i want that the result is: i try this: void findX(IplImage* imgSrc,int* min, int* max){ int i; int minFound=0; CvMat data; CvScalar…
Jayyrus
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GWT Image Cropping

I'm building a website using GWT and would like to add Image Cropping capability so users can upload their profile image and then crop it as they need to. I'm looking for something similar to Jcrop but in GWT. I found THIS and THIS code samples how…
Maksim
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How do I convert a MATLAB image processing program to java?

I've written an image processing program in MATLAB which makes heavy use of the MATLAB Image Processing Toolbox, especially the morphological operations (imopen, imclose) as well as imadjust. We do a lot of spline fit operations and medfilt2 and…
Joe Soul-bringer
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How to detect Text Area from image?

i want to detect text area from image as a preprocessing step for tesseract OCR engine, the engine works well when the input is text only but when the input image contains Nontext content it falls, so i want to detect only text content in image,any…
chostDevil
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Let User Crop Photo in iOS App

There are several questions (and answers) concerning cropping of images/photos within an iPhone app. But I couldn't find an answer covering the common task of giving the user a rectangle which can be resized with a pinch gesture to letting him…
j7nn7k
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How is the user id image generated on SO?

I am a little curious about the cute little kaleidoscopic images associated with each user on this site. How are those generated? Possibilities are: A list of images is already there in some folder and it is chosen randomly. The image is generated…
nullDev
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How to mask an image in IOS sdk?

I want to apply an image filter or mask when a word drawn on the image.The word will have transparent effect to see through the background image. Is it possible in native IOS sdk or i need different api to perform this. This image consist of 2…
arindam
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OpenCV Build on Visual Studio LINK error

I have followed this tutorial here as mentioned exactly I now try to run simple OpenCV code on Visual Studio but it I keep getting linker errors. I am trying this OpenCV tutorial in particular Here is the error I keep getting : …
Saher Ahwal
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Detecting crosses in an image

I am working on a program to detect the tips of a probing device and analyze the color change during probing. The input/output mechanisms are more or less in place. What I need now is the actual meat of the thing: detecting the tips. In the images…
MrOrdinaire
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Why fourier transform is not possible on color images?

Why fourier transform(dft) is not possible on color images? Why only on gray scale images Fourier transforms is possible?
siddharth
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How to do a Gaussian filtering in 3D

How do i do a gaussi smoothing in the 3th dimension? I have this detection pyramid, votes accumulated at four scales. Objects are found at each peak. I already smoothed each of them in 2d, and reading in my papers that i need to filter the third…
Poul K. Sørensen
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