edge-detection

I would like to ask for more information on how Chamfer Matching algorithm (an edge matching algorithm) can be used to find 'similar' images. I would like to know if it is possible to place a 'score' for the matched results. Rudi The Chamfer Matching Algorithm basically calculates the distance (dis-similarity) between two images. The basic idea is to: Extract the edge/contours of a query image as well as target image. Take one point/pixel of contour in query image and find the distance of a closest point/pixel of contour in target image. Sum the distances for all edge points/pixels of query

How can I make these lines connect at the target points? The image is a result of a skeletonization process. I'm trying to segment each line as a region using Watershed Transform. MikeE 's answer is quite good: using dilation and erosion morphological operations can help a lot in this context. I want to suggest a little improvement, taking advantage of the specific structure of the image at hand. Instead of using dilation/erosion with a general kernel, I suggest using a horizontal kernel that will connect the endpoints of the horizontal lines, but will not connect adjacent lines to one another

I want to recognize digits from a credit card. To make things worse, the source image is not guaranteed to be of high quality. The OCR is to be realized through a neural network, but that shouldn't be the topic here. The current issue is the image preprocessing. As credit cards can have backgrounds and other complex graphics, the text is not as clear as with scanning a document. I made experiments with edge detection (Canny Edge, Sobel), but it wasn't that successful. Also calculating the difference between the greyscale image and a blurred one (as stated at Remove background color in image

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 - just as an example): http://i51.tinypic.com/5vzo0x.jpg Thanks! If you can use ImageMagick , there is the --charcoal filter : The charcoal effect is meant to simulate artist's charcoal sketch of the given image. The "-charcoal" operator is in some respects similar to

Hi currently i am working on an OCR reading app where i have successfully able to capture the card image by using AVFoundation framework. For next step, i need to find out edges of the card , so that i can crop the card image from main captured image & later i can sent it to OCR engine for processing. The main problem is now to find the edges of the card & i am using below code(taken from another open source project) which uses OpenCV for this purpose.It is working fine if the card is pure rectangular Card or Paper. But when i use a card with rounded corner (e.g Driving License), it is failed

can anyone help me how to count the number of non directional edge using opencv cannyedge detection? I have a cannyEdge image from opencv and I would like to have an histogram based on edge directions and there by i can count he number of directional and non directional edges. I think you are confusing edge detection with gradient detection. Canny provides an edge map based on the gradient magnitude (normally using a Sobel operator, but it can use others) because Canny only returns the thresholded gradient magnitude information it cannot provide you with the orientation information. EDIT : I