I'm trying to write a ridge detection algorithm, and all of the sources I've found seem to conflate edge detection with ridge detection. Right now, I've implemented the Canny edge detection algorithm, but it's not what I want: for example, given a single line in the image, it will effectively translate it to a double line of edges (since...
I have an image, taken from a live webcam, and I want to be able to detect a specific object in the image and extract that portion of it to do some further processing. Specifically, the image would be of a game board, let's say for the purposes of this question that it's a Sudoku game board. Here is a sample image. My initial approach...
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 ...
I am looking for a bit of clarification on how the algorithms implemented in Canny edge detection - Wikipedia entry - work. It seems pretty straightforward to perform noise reduction using a 2D Gaussian filter, but I have heard that using two 1D filters - how is this accomplished? It's also simple to calculate the gradient and edge dir...
I have started some simple project about Text Detection in images. And one of steps in solving this problem is implementation of Edge detector. I wanted to implement Shen Castan, because it gives better results with noisy images. Problem is that I cannot find anywhere some usefull resources about this algorithm. Does anyone knows how Sha...
I have some problems with OpenCVs cvCanny(...) and the Image data types it can handle. Well, maybe you guys/gals know a solution. I have a 32 bit float image and I want to perform cvCanny on it. The problem is cvCanny can only handle "IPL_DEPTH_8S" or U (signed / unsigned short), or at least that's what I suspect. The OpenCV manual doe...
Using images of articles of clothing taken against a consistent background, I would like to make all pixels in the image transparent except for the clothing. What is the best way to go about this? I have researched the algorithms that are common for this and the open source library opencv. Aside from rolling my own or using opencv is the...
I am developing a Mac OS X application which, as part of it's UI, will display many visual elements in it's main view which can be selected. These elements can be positioned really anywhere within the view. The UI will support various ways of selecting the elements: rectangular marquee selection, elliptical marquee selection, and 'free' ...
Hi, I am about to start developing an edge detection system (once I've read through a couple of books, which I'm doing so at good speed), but one thing I am wondering is the speed of an app like Matlabs (which can compile code to C++) vs AFORGE.NET for edge detecton. Is unmanaged code generally faster? Thanks ...
I recently wrote an extremely basic edge detection algorithm that works on an array of chars. The program was meant to detect the edges of blobs of a single particular value on the array and worked by simply looking left, right, up and down on the array element and checking if one of those values is not the same as the value it was curre...
I am working through the book "Learning OpenCV" from the O'Reilly series and am trying to perform a canny edge detection sample. Any grayscale image I choose seems to come up as having 3 channels, and to the best of my knowledge, canny only works with single channel images, so this always fails. I am even using the images provided by...
As part of an application that I'm developing for Android I'd like to show the user an edge-detected version of an image they have taken (something similar to the example below). To achieve this I've been looking at the Sobel operator and how to implement it in Java. However, many of the examples that I've found make use of objects an...
Hi, Been looking all over and figure I'd ask here. Has anyone ever seen an open source canny edge detection class written in PHP. Found that PHP5 with GD has an imagefilter with edge detection capability, but doesn't quite match what I need. Thanks, Tee ...
Hello, I am attempting to perform a zero-crossing edge detection on an image in OpenCV. I blur and use the cvLaplace() then scale it from (0, max). My question is: How can I access the pixel values in that image in such a way as to correctly identify negative values? Using the function provided by OpenCV (cvPtr2D) returns unsigned chars...
I want to get the boxes count in a warehouse by using image processing edge detection techniques. So I used Sobel algorithm to detect edges. Now I need to measure the edge length. Does anyone know how to get length of edges and any suitable algorithm to get final count ? ...
I'm doing some graphics processing and I have a logic where in I have a bitmap with edges and I disregard all table edges from the letters E.g. 0000000000 0111111110 0100000010 0102220010 0100200010 0100200010 0100000010 0111111110 0000000000 0 - background color 1 - ignored edges 2 - edges I need My logic is just simple, if a number...
I am thinking of implement a image processing based solution for industrial problem. The image is consists of a Red rectangle. Inside that I will see a matrix of circles. The requirement is to count the number of circles under following constraints. (Real application : Count the number of bottles in a bottle casing. Any missing bottles?...
Hi! I'm curious - is it possible to ahieve in PHP: 1) Send image file to server 2) Process image = detect edges and create simple strokes basing on the edges 3) Save file on server / send it to user's browser / whatever Here is some "sample" file ;P (as You can see it wasn't made using any edge detection enabled program, but by hand -...