How to open and process a video file like .mpeg or .avi using openCV's VideoCapture method in Java -

- 

    import org.opencv.core.core;             import org.opencv.core.mat;             import org.opencv.core.size;             import org.opencv.highgui.highgui;             import org.opencv.highgui.videocapture;             import org.opencv.imgproc.imgproc;              public class video             {                 public static void main(string[] args)                 {                     system.loadlibrary(core.native_library_name);              videocapture cap = new videocapture(0);      cap.open(1);      if(!cap.isopened())     {         system.out.println("no camera");     }      else     {         system.out.println("yes. camera");     }      mat frame = new mat();     cap.retrieve(frame);      highgui.imwrite("me1.jpg", frame);     mat frameblur = new mat();      imgproc.blur(frame, frameblur, new size(5,5));     highgui.imwrite("me2-blurred.jpg", frameblur);      imgproc.gaussianblur(frame, frameblur, new size(25, 25), 20);     highgui.imwrite("me3-blurred.jpg", frameblur);      cap.release();         }     }

i have used code open camera device , capture 3 different frames , made operations on it. but, couldn't open file .avi/.mpg/.mp4 etc., using {n_open} method of videocapture. there method in videocapture implementation here. because private , native method, method can't accesses using videocapture's object.

could 1 how using pure opencv 2.4.6 , java
(please dont suggest solution using processing libraries)

take on opencv 2.4.8. videocapture api has been extended of public videocapture(string filename) method. question remains why feature has been implemented late.

if using of recent version of opencv isn't acceptable reason, have several options:

  • rebuild opencv method marked public

  • hacky one: make copy of videocapture class (or extend original 1 , play reflection) public videocapture(string) constructor. give support native method private static native long n_videocapture(java.lang.string filename) creating own dll using c++ opencv api. (tested!)


Comments

Post a Comment

Popular posts from this blog

c# - How Configure Devart dotConnect for SQLite Code First? -

-
can configure following sample code ? when run following code, error : no entity framework provider found ado.net provider invariant name 'devart.data.sqlite' setting in machine.config <system.data> <dbproviderfactories> <add name="dotconnect sqlite" invariant="devart.data.sqlite" description="devart dotconnect sqlite" type="devart.data.sqlite.sqliteproviderfactory, devart.data.sqlite, version=4.6.287.0, culture=neutral, publickeytoken=09af7300eec23701" /> </dbproviderfactories> </system.data> after add below block code in app.config <?xml version="1.0"?> <configuration>   <configsections> <!-- more information on entity framework configuration, visit http://go.microsoft.com/fwlink/?linkid=237468 --> <section name="entityframework" type="system.data.entity.internal.configfile.entityframeworksection, entit...
Read more

java - Copying object fields -

-
what best way of copying classes when need have 2 independent variables? have simple class: public class myclass { boolean = false; string b= "not empty"; } do need make method : assign(myclass data ) { a= data.a; b= data.b; } is there automatic method copy (duplicate) objects in java? do need make method : pretty close. instead of making method, should make constructor. such constructors called copy constructor , , create them this: myclass(myclass data) { = data.a; b = data.b; } and create copy of instance, use constructor this: myclass obj1 = new myclass(); myclass obj2 = new myclass(obj1); copy constructor can tedious : using copy constructor create deep-copy can tedious, when class has mutable fields. in case, assignment create copy of reference, , not object itself. have create copy of fields (if want deep copy). can go recursive. a better way create deep copy serialize , deserialize object. why not use clone()? ...
Read more

c++ - Clear the memory after returning a vector in a function -

-
i have function processes , stores lot of data in , returns results vector of class. amount of data stored in function tremendous , want clear storage memory of function after finished job. necessary (does function automatically clear memory) or should clear memory function? update: vector<customers> process(char* const *filename, vector<int> id) { vector<customers> list_of_customers; (perform actions) return list_of_customers; } variables defined locally within function automatically released @ end of function scope. destructors objects called, should free memory allocated objects (if objects coded correctly). example of such object std::vector . anything you've allocated new must have corresponding delete release storage. try avoid doing own allocation , use raii instead, i.e. containers or smart pointers.
Read more