Convert 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 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 find non-transparent coordinate pixels of the above image...
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 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 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 I guess it's probably...
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...
View Articleopen cv in android and using ImgFun library
I have integrated open cv in android and using ImgFun library. but on some android devices its throwing error UnsatisafiedLinkError: dlopen failed "lib\x86\libimgfun.so" has invalid shdr offser/size:...
View ArticlePass SimpleBlobDetector object to findCirclesGrid in Android
Hi y'all, I am using OpenCV 3.2.0 on Android to detect an asymmetrical circle grid. I want to modify the default parameters of `SimpleBlobDetector` and pass it on `findCircleGrid()` to improve the...
View ArticleHistogram Equalization of color image Open CV SDK for java!
Dear Folks, I am working on an image processing app in android and I am trying to achieve Histogram equalization for color image. I could able to get it done for grey scale image since it has only one...
View Articlefailure to lock Surface in deliverAndDrawFrame
Apologies if this has been asked before (though I didn't find it through searching), but I've come across a problem where none of the frames passed through onCameraFrame allow me to do any processing...
View ArticleHow can i identify transparent and non-transparent pixel by iterating all...
I've a bitmap.Part of the bitmap is nontransparent and remaining transparent area. Using OpenCV Android Mat how can I identify nontransparent coordinates.?
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