opencv

Increasing camera capture resolution in OpenCV

In my C/C++ program, I'm using OpenCV to capture images from my webcam. The camera (Logitech QuickCam IM) can capture at resolutions 320x240, 640x480 and 1280x960. But, for some strange reason, OpenCV gives me images of resolution 320x240 only. Calls to change the resolution using cvSetCaptureProperty() with other resolution values just ...

Automatic image rotation based on a logo

We're looking for a package to help identify and automatically rotate faxed TIFF images based on a watermark or logo. We use libtiff for rotation currently, but don't know of any other libraries or packages I can use for detecting this logo and determining how to rotate the images. I have done some basic work with OpenCV but I'm not...

.Net (dotNet) wrappers for OpenCV?

I've seen there are a few of them. opencvdotnet, SharperCV, EmguCV, One on Code Project. Does anyone have any experience with any of these? I played around with the one on Code Project for a bit, but as soon as I tried to do anything complicated I got some nasty uncatchable exceptions (i.e. Msgbox exceptions). Cross platform (support...

openCV doesn't compile on Leopard

I've been for the past few hours trying to figure out why openCV doesn't compile on leopard. I've been googling for references but all point to a dead google group. So my question is quite simple: I've read INSTALL file, read all documentation i could find and still couldn't figure a solution for this. The compile breaks here (this is ...

Why do I get the exception - Unable to load DLL '?????.dll': The specified module could not be found.

I'm using Emgu.CV which is a C# wrapper for the OpenCV libraries. I changed the Emgu.CV source to invoke from the latest OpenCV library cv110.dll instead of cv100.dll and now I get this error (where ????? is cv110.dll). I have placed the cv110.dll file in all the same locations as the cv100.dll file however this does not help. On a br...

OpenCV Object Detection - Center Point

Given an object on a plain white background, does anybody know if OpenCV provides functionality to easily detect an object from a captured frame? I'm trying to locate the corner/center points of an object (rectangle). The way I'm currently doing it, is by brute force (scanning the image for the object) and not accurate. I'm wondering...

OpenCV's Python - OS X

I get the following error while building OpenCV on OS X 10.5 (intel): ld: warning in .libs/_cv_la-_cv.o, file is not of required architecture ld: warning in .libs/_cv_la-error.o, file is not of required architecture ld: warning in .libs/_cv_la-pyhelpers.o, file is not of required architecture ld: warning in .libs/_cv_la-cvshadow.o, file...

OpenCV Sample Program lkdemo

Hi, reference, OpenCv\samples\c\lkdemo.c Anybody know what does the following snippet of codes does ? Code extracted from lkdemo.c for( i = k = 0; i < count; i++ ) { if( add_remove_pt ) { double dx = pt.x - points[1][i].x; double dy = pt.y - points[...

iPhone and OpenCV

I know that OpenCV was ported to Mac OS X, however I did not find any info about a port to the iPhone. I am not a Mac developer, so that I do not know whether a Mac OS X port is enough for the iPhone. Does anyone know better than me? Edit: Thanks for the informed answer Adam. ...

BGR Color Space

I understand RGB --- value (0-255)Red,(0-255)Green,(0-255)Blue to form a color. What is exactly BGR color space ? How is it different from RGB color space ? ...

Writing AVI files in OpenCV

There example on the net and code given in Learn OpenCv,Orielly. After many attempts the out.avi file is written with 0 bytes. I wonder where i went wrong. The following are the code i used... int main(int argc, char* argv[]) { CvCapture* input = cvCaptureFromFile(argv[1]); IplImage* image = cvRetrieveFrame(input); if (!i...

OpenCv Blob/Contour labeling

Hi i have been working on this for a while and yet to have no good solution. I am reading a video frame by frame and am using background subtraction to ' identify the region where is there movement and use cvFindContours() to get the rectangle boundary of the moving objects. Assuming the program is kept simple there can be only 2 human...

How to convert an OpenCV IplImage to an SDL_Surface?

Hey all, I'm trying to write a program which takes an SDL_Surface, converts it to an IplImage, uses the cvBlobsLib to find blobs, paints the blobs as spots back over the image, then converts the output IplImage back to an SDL_Surface. I'm almost done: only converting the IplImage back to an SDL_Surface hasn't been done yet. This IplIma...

How to convert an 8-bit OpenCV IplImage* to a 32-bit IplImage*?

I need to convert an 8-bit IplImage to a 32-bits IplImage. Using documentation from all over the web I've tried the following things: // general code img2 = cvCreateImage(cvSize(img->width, img->height), 32, 3); int height = img->height; int width = img->width; int channels = img->nChannels; int step1 = img->widthStep; int s...

Why does OpenCV reject cvLoadImage("string.ext"), but accept cvLoadImage(argv[1])?

#include "cv.h" #include "highgui.h" #include <stdio.h> int main(int argc, char* argv[]){ cvNamedWindow("Window1", CV_WINDOW_AUTOSIZE); IplImage* image = 0; ->->image = cvLoadImage(argv[1]);<-<- if(!image) printf("Unable to load image!"); cvShowImage("Window1", image); char c = cvWaitKey(0); cvReleaseImage(&...

Strange behavior with OpenCV

Hi every one, When I compile my Windows application (called CrosslinesDetection) in Visual C++ 2005 including OpenCV 1.1, a computer vision library, I do not get any compile or link errors, but when I am running it, it gets to a point and freezes, and Windows says the following: "Unhandled exception at 0x7c915223 in CrosslinesDetection...

Smart pointers with a library written in C

I'm using C++ with the OpenCV library, which is a library image-processing although that's not relevant for this question. Currently I have a design decision to make. OpenCV, being a C library, has its data structures (such as CvMat) declared as structs. To create them, you use functions like cvCreateMat, and to release them, you use f...

The type initializer for 'Emgu.CV.CvInvoke' threw an exception.

If anyone who use Emgu openCv wrapper in .net 3.5 framework,please tell me why this exception appears,Its inner exception is unable to load cxcore.dll. ...

Advice on Background Subtraction

Hi, I'm new at openCV programming, and my final project requires I use Background Subtraction, however I am having trouble understanding it. I would appreciate any help in understanding it, as it is urgent. i mean, can anybody explain the algorithm of it and could you send me the program?? please......... ...

Compile OpenCV on Mac with FFMPEG instead of Quicktime

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