I'm using ARToolKit in an android app and i would like to do a features detection (probably with FREAK because now ARToolKit uses it) in an image. My goal is just to have the number of key points in the image. But I don't find the tools to do just this "simple" task.
Thank you in advance for your help
You should look at OpenCV and their implementation of FREAK. There are JAVA wrappers for OpenCV which work on android.
You'll find lot's of tutorials and info at their website and forum.
Here is a similar answer with C++ code. Shouldn't be hard to convert it to Java using OpenCV's own wrappers.
OpenCV FREAK: Fast Retina KeyPoint descriptor
Regards,
Daniel
Related
I need to read text from printed paper with my Android device, but I can't find other solution than OCR. Is there any way to scan text ? Or OCR is best? It can be text and numbers without bar-code. I need this for my school project and I am lost, please help.
Can you please send me some examples, code on github ?
There are many OCR libraries for android. The OpenCV(Open Computer Vision) library, Tesseract OCR Tool by google and Aspire are some OCR libraries available.
The OpenCV library can be used both in Java and C++ code. It can also be linked to a static or dynamic using runtime application called OpenCV Manager. You can find the documentations and tutorials here.
The Tesseract OCR Tool is an open source library maintained by google. Tess-two is the fork of Tesseract Tools for Android. You can take a look into some tutorials available.
http://rmtheis.wordpress.com/2011/08/06/using-tesseract-tools-for-android-to-create-a-basic-ocr-app/
http://imperialsoup.com/2016/04/29/simple-ocr-android-app-using-tesseract-tutorial/
There are some OCR scanner libraries which use the above tools which makes implementing OCR easier.
EasyOcrScannerAndroid
Tess-two-Example
I have sucesfully implemented face detection in my app using Android's Camera.FaceDetectionListener (following the Android Developers guide), but unfortunatelly some devices does not support this feature. Is there another way to achieve the same result?
I usually work with OpenCV to make image processing algorithms.
http://opencv.org/platforms/android.html
Its algorithms are much better than Android face detection, besides if you download the SDK you have a faceDetection example.
Here are the downloads:
http://opencv.org/downloads.html
The sdk, handles camera api 2, which it works at 30 fps, with a wrapper if you want to process video frames. Besides there are samples where you can mix Java OpenCV code with JNI code, to make so much faster your algorithm.
Unfortunately, these examples are made on Eclipse projects, but they are not difficult to merge into Android studio project.
I hope that these references are useful
Cheers.
Currently I am working on a project that detects disease in a leaf (spot/discolored), rice leaf in specific.
It is android based which uses Opencv library. Now the problem is I am very new to Android programming as well as in OpenCv. I just completed the setup.
Could you help me what functions or features in OpenCv are possible to use in my project? And also, do I need to use native c++ or plain java?
Thank you, and I am looking forward for your answer. Thanks.
segment the diseased part first. You can do that without using JNI part
Use contour to segment the disease part. Use histogram to identify the damage part.
I need to develop a facial features detection application by which I could be able to detect eyes,nose,lips,head along with its face. For this I opted for OpenCV. I had gone through many tutorials and also sample projects. There I could see the usage of haarcascade files through which I could detect the facial features while recording a video. As I know the location of haar cascade file.
But no site could tell me the complete implementation of haarcascade files in OpenCV android project.
Kindly provide me some sites regarding or give me some brief knowledge regarding the same.
That is a good approach for detecting faces using openCV. Since you are using android, you will probably not find code written in java but you can always modal it to work on android too. This is what I believe is the best approach. http://docs.opencv.org/master/d7/d8b/tutorial_py_face_detection.html#gsc.tab=0
http://docs.opencv.org/modules/contrib/doc/facerec/facerec_tutorial.html
This is another detailed use of different approaches using OpenCV.
Hope it helps, if you need help in changing the code you have to post what you've done so far and then I would be happy to help! Cheers!
http://opencv.willowgarage.com/wiki/Android or http://code.google.com/p/javacv/ ?
I am new to computer vision, and want to do something on the phone camera such as matching the current screen to the most similar image in the database.
Both of them are java, what are the differences? Which one should I use?
Thank you so much for helping!
JavaCV is a wrapper around some native libraries, including OpenCV.
In any case you are going to use OpenCV, either directly by writing your own wrapper or using OpenCV's Android wrappers or using JavaCV.
As said JavaCV uses several libs, so it has many more features than only OpenCV. If you need those features than naturally you'd choose JavaCV.