image processing - Implement Sobel Filter in Java - Normalize values -

-

i want implement sobel filter myself (actual no beautiful implementation). after doing convolution have no idea how calculate rgb values.

  • assumption: grey scaled image

    double [][] sobel_x =  {     { -1, 0, 1},     { -2, 0, 2},     { -1, 0, 1} };  double [][]    sobel_y =  {     { 1, 2, 1},     { 0, 0, 0},     {-1, -2, 1} };  for(int y=1; y<image.getheight()-1; y++) {     for(int x=1; x<image.getwidth()-1; x++)     {        color = new color(image.getrgb(x-1, y-1));        color b = new color(image.getrgb(x, y-1));        color c = new color(image.getrgb(x+1, y-1));        color d = new color(image.getrgb(x-1, y));        color e = new color(image.getrgb(x, y));        color f = new color(image.getrgb(x+1, y));        color g = new color(image.getrgb(x-1, y+1));        color h = new color(image.getrgb(x, y+1));        color = new color(image.getrgb(x+1, y+1));          double pixel_x =    (sobel_x[0][0] * a.getred()) + (sobel_x[0][1] * b.getred()) + (sobel_x[0][2] * c.getred()) +                             (sobel_x[1][0] * d.getred())   + (sobel_x[1][1] * e.getred())   + (sobel_x[1][2] * f.getred()) +                             (sobel_x[2][0] * g.getred()) + (sobel_x[2][1] * h.getred()) + (sobel_x[2][2] * i.getred());         double pixel_y =                              (sobel_y[0][0] * a.getred()) + (sobel_x[0][1] * b.getred()) + (sobel_x[0][2] * c.getred()) +                             (sobel_y[1][0] * d.getred())   + (sobel_x[1][1] * e.getred())   + (sobel_x[1][2] * f.getred()) +                             (sobel_y[2][0] * g.getred()) + (sobel_x[2][1] * h.getred()) + (sobel_x[2][2] * i.getred());            //here possible values between [-1020, 1020]                 //how going on          //int rgb = (int) math.sqrt(pixel_x*pixel_x+pixel_y*pixel_y);          //int rgbasint = (int)(65536 * rgb + 256 * rgb + rgb);           } }

one of ideas linear transformation. example, minimum pixel value in image got -998 , maximum 1000. can correspond -998 0 , 1000 255, relationship between scale of (-998,1000) scale of (0,255) , normalize values between [-998,1000] [0,255].


Comments

Post a Comment

Popular posts from this blog

javascript - how to protect a flash video from refresh？ -

-
<!doctype html> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title>flash video refresh</title> </head> <body> <div id="playerzone"><embed height="496" width="580" flashvars="flvid=19742822&amp;createtime=2012-4-19 13:46:33" wmode="opaque" allowscriptaccess="always" allowfullscreen="true" quality="high" bgcolor="#000000" name="player" id="player" src="swf/mine.swf" type="application/x-shockwave-flash"></div> <a onclick="return test();" id="test">click me popup div,and hide scrollbar</a> </body> the code upon： for example,when click a#test button,popup div,it's no problem,but want hide scrollbar while div popup. i used $('html').css('overflow','hidden') in...
Read more

visual studio 2010 - Connect to informix database windows form application -

-
i trying figure out how connect ibm informix database. have been doing research , have found threads 5 years ago examples not working. i have installed latest sdk ibm informix. i have included ibm.data.informix.dll references in project. i have included using ibm.data.informix; i adding button , on click testing conenction. debug error "sql0035n file "c:\users\adam\documents\visual studio 2010\projects\test\test\msg\en_us\db2nmp.xml" cannot opened." this file not exist , dont see anywhere in program files (x86)\ibm informix client sdk directory. my on click code is private void button1_click(object sender, eventargs e) { const string host = "192.168.obfuscated"; const string servicenum = "1525"; //port? const string server = "serverobfuscated"; const string database = "dbobfuscatedy"; const string user = "myusername"; const string password = ...
Read more

android - Associate same looper with different threads -

-
Image
in application, want create multiple threads working on single queue. create queue know need call looper.prepare() . i want other threads create should associated looper created first thread, how can achieve this? use 1 of java thread safe queue class java.util.concurrent package instead of looper achieve goal. it's more common practice. share queue between threads , post task queue entry 1 thread can entry thread. blockingqueue can - in 1 thread call take() , block thread until thread put() entry queue. that's all. producer consumer pattern example blockingqueue or concurrentlinkedqueue about blockingqueue
Read more