Question about polar or radial angle calculation in the image coordinate system
Hi, I have general questions, not explicitly about OpenCV, but related to image processing: The image coordinate system normally has the x-axis pointing from left to right, and the y-axis pointing...
View ArticleHow can I use the GPU with Qt? (non-nvidia)
Hello everyone, this is my first time with OpenCV. I am sorry I couldn't formulate my question better, I have been searching the Internet and the tags on OpenCV Answers but I couldn't solve my problem....
View ArticleNative Android OpenCV + Unity3D 5
Hello, I am trying to develop an Unity3D game using the OpenCV Android implementation. Using the **ColorBlobDetector** example (http://opencv.org/platforms/android/opencv4android-samples.html) I try...
View ArticleUsing GPU with OpenCV 3.0
Hi All, I noticed that gpu module for opencv 3.0rc1 is no longer available as compared to the 2.4.x versions. How can i use GPU with opencv 3.0 current releases. Your help will be duly appreciated....
View Article[Solved] Linking on Mac OSX
When I try to link the program on Mac OSX I obtain the error Undefined symbol for architecture x86_64: "cv::CascadeClassifier::detectMultiscale..." On Linu I haven't got any error. Can someone suggest...
View ArticleProcess JPG and PNG formats with Opencv for iOS platform
Hello, I need to read and process JPG and PNG images (in other words obtain the Mat representation) with the OpenCV iOS version. **I can't use specific system API** to do this (e.g. using UIImage with...
View Articleimshow a mat
how do i show a mat.. It contains the output from a DFT.. but I cannot view the output using imshow.
View ArticleError in SURF GPU using ROI?
I am using VS2012 C++/CLI on a Win 8.1 64 bit machine with OpenCV 3.0. I am trying to implement the GPU version of SURF. When I do not specify an ROI, I have no problem. Thus, the following line gives...
View ArticleStereo rectification without calibration?
Dear all, I have two older cameras (Canon Ixus 860IS) mounted as a stereo rig. Now I want to use OpenCV to calculate the alignmment of left and right image and then watch the image using a stereo...
View Articlemat from buffer
I try to capture video from frame grabber. What I did is I point raw data from buffer into Mat as follow: myMat = Mat(Size (x, y), CV_8UC1, ImaqBuffer); Image below (picture 1) show what I got from...
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 ArticleAkaze Error (-215) color.cpp
Hi ! I'm following the tutorial : http://docs.opencv.org/3.0-beta/doc/tutorials/features2d/akaze_matching/akaze_matching.html I'm on Debian. The compilation is good, I had an error on matmul, I...
View ArticleOPENCV CAMERA FEED STREAMING
Hello Im fairly new to Opencv and I'm getting my hands dirty with android and desktop applications using opencv. I've been wondering is there any way that i can send my live camera feed from my phone...
View ArticleOpenCV compile error
On Compiling opencv 2.4.11 on the ubuntu 14.04, I received the following error: - Linking CXX shared library ../../lib/libopencv_core.so /usr/bin/ld: skipping incompatible...
View Articlecv::VideoCapture::set failed on image sequence
I am trying to use a cursor to seek a specific frame in stream. main.cpp code follows: #include #include int main() { cv::VideoCapture cap; if (!cap.open("8%d.jpg")) return 1; double index =...
View Articleeye blinks detection from video frames
Hi I want to detect blinks from video frames that recorded using eye glasses like the image in the attachment . What is the best way to do this ? Thanks [1.JPG](/upfiles/14434390534539969.jpg)
View ArticleOpenCV Manager on Samsung Galaxy Edge
Good day everyone I recently had a problem with my Samsung Galaxy Edge (SM-G925F): neither my own app nor the OpenCV Demo apps I installed from the Google Play Store did work. When I opened the apps,...
View ArticleOpenCV4Android - Get 16bit pixel values?
Is there a way to get 16bit values back from a pixel on a Mat? Mat.get() seems to only return 8bit values... And I'd really like a more exact number there. Thanks
View Articlecv2.CalcOpticalFlowBM() does not exist in Opencv-3.0.0
Hi, I used to use cv2.CalcOpticalFlowBM() a long time back. Now I upgraded to Opencv-3.0.0 and could not find it. I went to an earlier version of Opencv 2.4.9, and I still could not find it. It seems...
View ArticleHow to initialize a FeatureDetector with OpenCV 3?
With OpenCV 3 I get a SegFault when running the `detect()` function of either the ORB or AKAZE detector although the pointer is not null. I assume that something is not initialized. But my compiler is...
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