Texture Direction ( angle of Dominating Texture in Image)

[ashamim]

Hello Everyone

I have been trying to calculate the Texture direction of some sample images for example to remove some strips from the images I need to know their direction first. I don't know why but every time i get either 0 degrees or 90 degrees. I have even tried to create sample images on my own in which i have different angles for the dominating texture. On fourier transform plot the dominating direction is visible and is perpendicular to the one in spatial domain direction but i dont know why i dont get the right angle.

Following is my code.

Any help will be highly appreciated

 void calculate_std_stdi(Rectangle r)
          {
         
          double M  = r.width;
          double pi = Math.PI;
          double angle = pi/M;
          float [][]aspec = new float[r.width][r.height];
          double temp_aas = 0.0;   // average amplitude sum for stdi
         
          double temp_ang = 0.0;   // temporary angle having max amplitude sum for Fourier Spectrum
          double temp_ang2 = 0.0;  // temporary angle having max amplitude sum for Power Spectrum
          double temp = -Float.MAX_VALUE;   // temp values to check the max amplitude sum of fourier spectrum
          double temp2 = -Float.MAX_VALUE;  // temp value to check the max amplitude sum of Power Spectrum
         
         
          double i = 0;
          for(int x = 0 ; x<r.width; x++)
                {
                angle = pi/M;
                angle = angle*i;
                double temp_amp = 0.0;
                double temp_amp2 = 0.0;
                double j =1;
                        for(int y = 1; y<(r.width/2)-1; y++)
                        {
                        double  u1 = M/2.0 + (j * Math.cos(angle));
                        double  v1 = M/2.0 + (j * Math.sin(angle));
                        double u11 = M/2.0 - (j * Math.cos(angle));
                        double v11 = M/2.0 - (j * Math.sin(angle));
                        int u = (int)(u1+0.5);
                        int v = (int)(v1+0.5);
                        double temp_u = (double)u;
                        double temp_v = (double)v;
                       
                                if(temp_u == u1 && temp_v == v1)
                                        {
                                        temp_amp += (double)temp_mag[(int)u1][(int)v1];
                                        temp_amp2 += ip1.getPixelValue((int)u1,(int)v1);
                                        aspec[(int)u11][(int)v11] = (float)temp_mag[(int)u11][(int)v11];
                                        }
                   
                                        else
                                        {
                                        temp_amp += (double)(temp_mag[u][v]*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) + temp_mag[u+1][v]*((u1-temp_u))*(1.0-(v1-temp_v)) + temp_mag[u][v+1]*(1.0-(u1-temp_u))*((v1-temp_v)) + temp_mag[u+1][v+1]*((u1-temp_u))*((v1-temp_v)));
                                        aspec[(int)u11][(int)v11] = (float)(temp_mag[u][v]*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) + temp_mag[u+1][v]*((u1-temp_u))*(1.0-(v1-temp_v)) + temp_mag[u][v+1]*(1.0-(u1-temp_u))*((v1-temp_v)) + temp_mag[u+1][v+1]*((u1-temp_u))*((v1-temp_v)));
                                        temp_amp2 += (ip1.getPixelValue(u,v)*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) + ip1.getPixelValue(u+1,v)*((u1-temp_u))*(1.0-(v1-temp_v)) + ip1.getPixelValue(u,v+1)*(1.0-(u1-temp_u))*((v1-temp_v)) + ip1.getPixelValue(u+1,v+1)*((u1-temp_u))*((v1-temp_v)));
                                        }
                    j+=1.0;
                        }
                       
               
                                        if (temp_amp > temp)
                                        {
                                        temp = temp_amp;
                                        temp_ang = angle;
                                        }
                                        if(temp_amp2 > temp2)
                                        {
                                        temp2 = temp_amp2;
                                        temp_ang2 = angle;
                                        }
                temp_aas += temp_amp2;
                i+=1.0;
                }
                 
                 
               
                /*ImageProcessor ipp = new FloatProcessor(aspec);
                ImagePlus impp = new ImagePlus("Angular Spectrum", ipp);
                impp.show();
                */
               
                double temp_stdi = temp_aas/(M*temp2);
                std = temp_ang *(180.0/pi);
                //if(std >= 90.0)
                //std = std - 90.0;
                //std = temp_ang;
                //std2 = temp_ang2;
                //else
                //std = std+90.0;
                std2 = temp_ang2 * (180.0/pi);
                //if(std2 >= 90)
                //std2= std2 - 90;
                //else
                //std2 = std2+90;
                stdi = temp_stdi;
         }

Best Regards

Ahsan

[ashamim]

sorry i didnt mention in my code

temp_amp is the fourier transform i have calculated my self

and

temp_amp2 is the power spectrum from the FHT class.


B.R

[Daniel James White]

Hi Ahsan

For directionality of structures Jean-Yvez Tinevez wrote a nice plugin for us
which is bundled in Fiji.

Its called Directionality:
http://fiji.sc/wiki/index.php/Directionality

It uses Fourier components or local gradient.

@Pasi - did you know you have a colleague at Abo.fi who is doing image analysis in Java?

cheers

Dan



On Aug 12, 2011, at 6:00 AM, IMAGEJ automatic digest system wrote:

>
> Date:    Thu, 11 Aug 2011 01:57:13 -0700
> From:    ashamim <[hidden email]>
> Subject: Texture Direction ( angle of Dominating Texture in Image)
>
> Hello Everyone
>
> I have been trying to calculate the Texture direction of some sample images
> for example to remove some strips from the images I need to know their
> direction first. I don't know why but every time i get either 0 degrees or
> 90 degrees. I have even tried to create sample images on my own in which i
> have different angles for the dominating texture. On fourier transform plot
> the dominating direction is visible and is perpendicular to the one in
> spatial domain direction but i dont know why i dont get the right angle.
>
> Following is my code.
>
> Any help will be highly appreciated
>
> void calculate_std_stdi(Rectangle r)
>  {
>  
>  double M  = r.width;
>  double pi = Math.PI;
>  double angle = pi/M;
>  float [][]aspec = new float[r.width][r.height];
>  double temp_aas = 0.0;   // average amplitude sum for stdi
>  
>  double temp_ang = 0.0;   // temporary angle having max amplitude sum for
> Fourier Spectrum
>  double temp_ang2 = 0.0;  // temporary angle having max amplitude sum for
> Power Spectrum
>  double temp = -Float.MAX_VALUE;   // temp values to check the max
> amplitude sum of fourier spectrum
>  double temp2 = -Float.MAX_VALUE;  // temp value to check the max
> amplitude sum of Power Spectrum
>
>  
>  double i = 0;
>  for(int x = 0 ; x&lt;r.width; x++)
> {
> angle = pi/M;
> angle = angle*i;
> double temp_amp = 0.0;
> double temp_amp2 = 0.0;
> double j =1;
> for(int y = 1; y&lt;(r.width/2)-1; y++)
> {
> double  u1 = M/2.0 + (j * Math.cos(angle));
> double  v1 = M/2.0 + (j * Math.sin(angle));
> double u11 = M/2.0 - (j * Math.cos(angle));
> double v11 = M/2.0 - (j * Math.sin(angle));
> int u = (int)(u1+0.5);
> int v = (int)(v1+0.5);
> double temp_u = (double)u;
> double temp_v = (double)v;
>
> if(temp_u == u1 &amp;&amp; temp_v == v1)
> {
> temp_amp += (double)temp_mag[(int)u1][(int)v1];
> temp_amp2 += ip1.getPixelValue((int)u1,(int)v1);
> aspec[(int)u11][(int)v11] = (float)temp_mag[(int)u11][(int)v11];
> }
>  
> else
> {
> temp_amp +=
> (double)(temp_mag[u][v]*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) +
> temp_mag[u+1][v]*((u1-temp_u))*(1.0-(v1-temp_v)) +
> temp_mag[u][v+1]*(1.0-(u1-temp_u))*((v1-temp_v)) +
> temp_mag[u+1][v+1]*((u1-temp_u))*((v1-temp_v)));
> aspec[(int)u11][(int)v11] =
> (float)(temp_mag[u][v]*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) +
> temp_mag[u+1][v]*((u1-temp_u))*(1.0-(v1-temp_v)) +
> temp_mag[u][v+1]*(1.0-(u1-temp_u))*((v1-temp_v)) +
> temp_mag[u+1][v+1]*((u1-temp_u))*((v1-temp_v)));
> temp_amp2 +=
> (ip1.getPixelValue(u,v)*(1.0-(u1-temp_u))*(1.0-(v1-temp_v)) +
> ip1.getPixelValue(u+1,v)*((u1-temp_u))*(1.0-(v1-temp_v)) +
> ip1.getPixelValue(u,v+1)*(1.0-(u1-temp_u))*((v1-temp_v)) +
> ip1.getPixelValue(u+1,v+1)*((u1-temp_u))*((v1-temp_v)));
> }
>    j+=1.0;
> }
>
>
> if (temp_amp &gt; temp)
> {
> temp = temp_amp;
> temp_ang = angle;
> }
> if(temp_amp2 > temp2)
> {
> temp2 = temp_amp2;
> temp_ang2 = angle;
> }
> temp_aas += temp_amp2;
> i+=1.0;
> }
>
>
>
> /*ImageProcessor ipp = new FloatProcessor(aspec);
> ImagePlus impp = new ImagePlus("Angular Spectrum", ipp);
> impp.show();
> */
>
> double temp_stdi = temp_aas/(M*temp2);
> std = temp_ang *(180.0/pi);
> //if(std >= 90.0)
> //std = std - 90.0;
> //std = temp_ang;
> //std2 = temp_ang2;
> //else
> //std = std+90.0;
> std2 = temp_ang2 * (180.0/pi);
> //if(std2 >= 90)
> //std2= std2 - 90;
> //else
> //std2 = std2+90;
> stdi = temp_stdi;
> }
>
> Best Regards
>
> Ahsan
>
> -----
> Ahsan
> --
> View this message in context: http://imagej.588099.n2.nabble.com/Texture-Direction-angle-of-Dominating-Texture-in-Image-tp6675577p6675577.html
> Sent from the ImageJ mailing list archive at Nabble.com.

Dr. Daniel James White BSc. (Hons.) PhD
Senior Microscopist / Image Visualisation, Processing and Analysis
Light Microscopy and Image Processing Facilities
Max Planck Institute of Molecular Cell Biology and Genetics
Pfotenhauerstrasse 108
01307 DRESDEN
Germany

[phone] (German Mobile)
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dan (at) chalkie.org.uk
( white (at) mpi-cbg.de )

[ashamim]

Hello Dan

Thanks alot for the reply I really appreciate that. Though I  have solved the problem at my end but this is a very useful link for me and some nice work done.

B.R

Ahsan