computer-vision

What are some popular OCR algorithms?

I've been interested in machine learning and computer vision for a while, so I've decided to attempt to build a simple Optical Character Recognition demo in C#. I'm looking for a description of some common OCR algorithms and how I would go about implementing them in C#. It's a learning exercise so I'm not looking for an OCR library. ...

Machine vision in Python

I would like to perform a few basic machine vision tasks using Python and I'd like to know where I could find tutorials to help me get started. As far as I know, the only free library for Python that does machine vision is PyCV (which is a wrapper for OpenCV apparently), but I can't find any appropriate tutorials. My main tasks are to ...

Cannot make VW34 (Oxford Active Vision Lab libraries) in Ubuntu 8.0.4

I'm trying to make a pretty obscure app called VW34 which is a computer vision library that uses openGL. I'm getting an error during make after most of the app compiles successfully "GeomObjects/point3d.cpp:88: error: ‘VW::Point3D VW::operator+(const VW::Point3D&, const VW::Point3D&)’ should have been declared inside ‘VW’" . Supposedly ...

Robust Face Detection in C/C++?

I'm looking for a robust face detection algorithm/library, preferably in C (C++ is okay too; other languages I can port if necessary). I've used OpenCV's implementation in the past, but I don't think it's invariant to rotation. Doesn't need to be real-time, but it shouldn't be horrendously slow either (maybe one or two seconds per photo ...

Computer Vision with Mathematica

Hi all does anybody here do computer vision work on Mathematica? I would like to know what external libraries are available for doing that. The built in image processing functions are not enough. I am looking for things like SURF, stereo, camera caliberation, multi-view geometry etc.. How difficult would it be to wrap opencv for use in...

Face recognition Library

I'm looking for a free face recognition library for a university project. I'm not looking for face detection. I'm looking for actual recognition. That means finding images that contain specified faces or libraries that calculate distances between specific faces. I'm using OpenCV for detecting the faces and a rough Eigenfaces Algorithm...

How to recognize vehicle license / number plate (ANPR) from an image?

Hi all, I have a web site that allows users to upload images of cars and I would like to put a privacy filter in place to detect registration plates on the vehicle and blur them. The blurring is not a problem but is there a library or component (open source preferred) that will help with finding a licence within a photo? Caveats; I ...

What algorithm could be used to identify if images are the "same" or similar, regardless of size?

TinEye, the "reverse image search engine", allows you to upload/link to an image and it is able to search through the billion images it has crawled and it will return links to images it has found that are the same image. However, it isn't a naive checksum or anything related to that. It is often able to find both images of a higher res...

An algorithm for a drawing and painting robot - any tips?

Algorithm for a drawing and painting robot - Hello I want to write a piece of software which analyses an image, and then produces an image which captures what a human eye perceives in the original image, using a minimum of bezier path objects of varying of colour and opacity. Unlike the recent twitter super compression contest (see:...

Corner detection algorithm for mobile

Hi, I am trying to find a good algorihtm that would detect corners in a image in a mobile phone. There are multiple algorithms to do that I am not sure which one will perform better in a memory and processor limited environment. Specifically I am trying to find a sudoku grid in a picture taken using the camera of the phone. I am using...

Face detection in java

Can anyone recommend a decent java library for face detection (recognition not required, just detection). The library would preferably be pure java (e.g. no dependencies on other native libs, DLLs or such). Platforms: Linux is a must; OS X and windows are very nice to have. Performance isn't a big deal, can be slow, it's for server offli...

proportions of a perspective-deformed rectangle

Given a 2d picture of a rectangle distorted by perspective: I know that the shape was originally a rectangle, but I do not know its original size. If I know the pixel coordinates of the corners in this picture, how can I calculate the original proportions, i.e. the quotient ( width / height ) of the rectangle? (background: the goal ...

Favorite technique for hand gesture recognition

There is a lot of research going on about gesture recognition. I figured I would narrow this down to the topic of hand gesture recognition (i.e. stationary hand positions, up to as complex and dynamic as sign language recognition). Considering the image processing techniques available in real-time, such as blob detection, edge detection...

Starting semantic image recognition

How to recognize (in)appropriate images? To facilitate, enable and easify photo and image moderation and administration targeting gae, I try get started with basic python image recognition ie basic semantic information what the image looks like to hold back doubtful material until human can judge it, and to approve the most that are goo...

Downhill Simplex Method

Is it possible to use Downhill Simplex Method for template matching?Let's say I have 40 landmarks on the edges of an object and I have pixel intesities of normal vectors on these landmarks and I want to use Downhill Simplex Method for strecthing the template I have with iterations after each iteration i will check mean square of errors ...

OCR Playing Cards

I decided to do a project for fun where I want to take as input the image of a playing card and return its rank and suit. I figure that I only need look at the upper-left corner, since that has all the information. It should be robust - if I have a large image of an Ace of Diamonds, I should be able to scale it anywhere from 20 to 200% a...

finding Image shift

Hi, How to find shift and rotation between same two images using programming languages vb.net or C++ or C#? Please help urgent ...

Rectangle detection with Hough transform

I'm trying to implement rectangle detection using the Hough transform, based on this paper. I programmed it using Matlab, but after the detection of parallel pair lines and orthogonal pairs, I must detect the intersection of these pairs. My question is about the quality of the two line intersection in Hough space. I found the intersec...

OpenCV: Detect blinking lights in a video feed

I have a video feed. This video feed contains several lights blinking at different rates. All lights are the same color (they are all infrared LEDs). How can I detect the position and frequency of these blinking lights? Disclaimer: I am extremely new to OpenCV. I do have a copy of Learning OpenCV, but I am finding it a bit overwhelming....

Best articles to start learning about edge detection/image recognition

Hi, I am involved in a personal project which will require pretty extensive knowledge of edge detection and image segmentation/object recognition. I know the importance of planning/understanding before writing code and with this in mind, what is the best place to start, to learn about these areas of computing? I am ideally looking for ...