Create ROI from a set of points > 4
Is it possible to create a roi which is non rectangular?
View ArticleAndroid App don't load SVM trained (on C++) file for recognition
I've trained a svm using OpenCV 3.2 on C++. Just like that // Set up SVM's parameters Ptr svm = SVM::create(); svm->setType(SVM::C_SVC); svm->setKernel(SVM::LINEAR); svm->setC(100);...
View Articlehow to cut out video frame automatically when the camera is opened
There is a sample which can cut out the video frame in the official SDK. Now I want to change it to be a sample which can cute out video frame automatically. Anyway! Thanks for answers!
View ArticleChanges to OpenCV code
Hi All, I am busy with a project using OpenCV 3.2.0 and Android... I have come across some issues with regards to using the camera flash. Which I have fixed, but I have added code to...
View ArticleWhere is the lib file **mixed_sample.so** ?
I'm trying to compile the tutorial-2-mixedprocess application in android, this application comes with the sdk. But my application crashes when it tries to load **mixed_sample** // Load native library...
View ArticleI've a bitmap image which contain both transparent area and non-transparent...
 I've to find this angle of the image and change its perspective as per its angle. I use the following code to achieve that Bitmap sourceBitmap =...
View ArticleConvert background to white
Hi, I have already finished my document scanner but I'm trying to improve the results. I correctly detect edges, crop and fix perspective of the document but I wanted to improve the readability of the...
View ArticleHistogram in Opencv
I have two questions: 1) I have segmented an image from the background and the result is a colored circle with a black background. When I do histogram using calcHist(), is the result will be the...
View Articleis it possible to detect color around white color ?
Hello, i am new in opencv. i want to detect green,blue and red color that is around white brightest color and i want rectangle of that detected contours. i have tried with Core.inRange but it giving me...
View ArticleFinding sum using mask in opencv
I want to sum only non zero pixel value, so is there any function in opencv to get that like the function mean(src, mask) as I used sumElmes() but it gives the sum of all values. Any suggestions or...
View ArticleColor based classification using SVM
I would like to ask a question about how to use SVM to classify images based on colors: I have a dataset which contains 15 features extracted using simple image histogram includes mean, stddev, mode,...
View ArticleImage Marker Recognition - ANDROID
Hello! I am not OpenCV expert! I need to develop an Android App that recognizes images of Marker saved in memory. I have developed an App that uses the "public Mat onCameraFrame(CvCameraViewFrame...
View ArticleCouldn't load xfeature2D from loader dalvik.system.PathClassLoader
I am trying to include xfeature2d in my Android App and got the error message java.lang.UnsatisfiedLinkError: Couldn't load xfeature2D from loader dalvik.system.PathClassLoader as in this photo ![image...
View ArticleContour detection for gray stickers on white background.
Hi all, I want to detect the outline (contour) of gray and orange colored post-it stickers (16:9 size and might be rotated) like the photo I attached but I'm having a difficulty achieving this because...
View ArticleFilled circle are not detecting
Hello, I am new to opencv and trying to make omr scanner from scratch and have snippet which is supposed to detect filled circles but it is doing quite opposite and detecting unfilled circle. Please...
View Articleresize an image
I am resizing my images to apply k-means for segmenting images and get ROI. I am using the following code from the book: mastering opencv android application programming: int scaleFactor =...
View Articlehow to display image using opencv on Android device
. I am getting package related errors while running the application. I am adding the screenshot related that. I have already installed all the required packages....
View ArticleHow to display processed Mat format image for android. Is there any...
imshow() is working for Linux only. I want to display image for android device. Does any imshow() equivalent function for andrid?
View Articlefind contours miss some objects
I use the following code to read through all objects that I segmented from my image which should be ordered in row and columns as semi-circle (because of segmentation and morphological processing for...
View ArticleAndroid VideoCapture File Format and Alternatives
Hi all, I'm trying to create an android application that will frame-by-frame process video files taken with a phone camera (.mp4) with openCV. Having looked at previous questions on this subject, I...
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