Extract Y channel from YCrCb
Hi I want to separate YCrCb channels , I have written this code that converts from RGB to YCrCb , I need help to separate the YCrCb channels and display them Thanks #include "opencv2/core/core.hpp"...
View Articledrawing contour to any object of image
hi, my purpose is to draw a contour to surrounding the object which has a wanted color, I can detect any color from image and I know how to draw contour to surrounding of all objects in image , but for...
View ArticleInformative websites related to OpenCV
i think it will be useful if we add links of informative websites related to OpenCV here. Lets create a list together. - **C ++** - http://www.bogotobogo.com - https://github.com/MasteringOpenCV/code -...
View Articledraw histogram output
Hi I have got the histogram of Y channel of YCrCb the output after drawing with this code int hist_w = 512; int hist_h = 400; int bin_w = cvRound( (double) hist_w/histSize ); Mat histImage( hist_h,...
View ArticleOpenCV4Android - Utils.loadResource loading in a greater than 8bit image
private Mat loadMatFromResource(int resource) { Mat image = new Mat(); try { image = Utils.loadResource(getApplicationContext(), resource, Highgui.CV_LOAD_IMAGE_UNCHANGED); } catch(IOExecption e) {...
View ArticleKalman Filter Question
Hello forum, I am trying to understand the theory behind kalman filter and I have a question to ask. I am following the tutorial shown here....
View ArticleHSV Thresholding Difference between ImageJ and OpenCV
I use ImageJ before using OpenCV functions because in ImageJ I can use their interactive HSV thresholding tool to get the HSV parameters I want to threshold using OpenCV functions. After using ImageJ...
View Articleproblem in training the model using createFisherFaceRecognizer
i have been used opencv c++ library to detect faces and save theme to my desk then i make database with the images path and there labels. after call theme back to two vectors of the images and labels...
View ArticleCan we Use haar cascade or background subtraction for confidence level of...
Can we use haar cascade or background subtraction for confidence level of object detection ?  Thank You.
View ArticleIs bow.cluster() multithreaded?
I run bow.cluster() on my computer and it shows CPU usage of 700%. Is it because the K-mean part here multi-threaded or any other reason? Thanks
View ArticleBoundary detection-What function will be the best for this?
[C:\fakepath\goal.jpg](/upfiles/13843900444768243.jpg) Hi guys, My goal is to draw a line on the boundary between the grass and concrete as in the...
View ArticleHow to Create a GPU Mask and Fill It With A Scalar For an ROI
I am using OpenCV 3.0 with VS2012 C++/CLI on a Win 8.1 64 bit machine. In addition, I have an NVidia GTX 760 with CUDA 7.0. I am trying to detect SURF keypoints but only within an ROI. I got this...
View ArticleHEAP; corruption or bug when detect face using cascade classifier
My program run perfectly when I convert data from buffer into Mat (program to run video from external camera with frame grabber card). But after I try to develop a program to detect face, it has...
View ArticleHow to write or save sequence of images in a folder using opencv in ubuntu...
How to write or save sequence of images in a folder using opencv? I am trying to like this imwrite( "/home/administrator/Desktop/bg_sub/%d.jpg", image ); but it is storing only one image. Please tell...
View ArticleWhy degree from image is not the same at the theory in math?
Hello, I have question on the degree calculated from the atan function between two points (x1,y1) and (x2,y2). From what I get from the online tutorial, the formula would be atan((y2-y1)/(x2-x1)) and...
View ArticleIdentifying the left and right camera from 2 images captured at different...
I have been give with 2 camera images which sees the same scene but captured with different time. I will have to find out which image is being captured by which camera (Which camera is left and which...
View Articlecumulative histogram
Hi I'm confused a little bit about what it is cumulative histogram ? is that is the same histogram that is calculated with calcHist() function in open cv ? Thanks
View ArticleWhat exactly clusterCount does?
I am training a BOW classifier to classify some images, but I am not really sure what does `cluster_count – Number of clusters to split the set by` means. In fact what is the set: the image or the...
View ArticletriangulatePoints() function
I don't understand what exactly projPoints1 and projPoints2 are in triangulatePoints() built-in function of calib3d module. Here is the C++ API of triangulatePoints(): void triangulatePoints(InputArray...
View ArticleWLD: A Robust Local Image Descriptor
I have recently read this paper: "WLD: A Robust Local Image Descriptor" [1] [PDF](http://vipl.ict.ac.cn/sites/default/files/papers/files/2010_PAMI_jchen_WLD-A%20Robust%20Local%20Image%20Descriptor.pdf)...
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