X-Git-Url: https://hackdaworld.org/gitweb/?p=physik%2Fnlsop.git;a=blobdiff_plain;f=dft.c;h=1d26cee7a2a1e6ab25c5cb003fed73d9c189861c;hp=385c22d01b6e3261a5507e894825801e1db285ff;hb=e7f9c4ef1dd8eb2a19fe98091db7d06834643ea9;hpb=ba07742cd1c1cf50e5467462311425cfdf245402

diff --git a/dft.c b/dft.c
index 385c22d..1d26cee 100644
--- a/dft.c
+++ b/dft.c
@@ -12,30 +12,102 @@ int main(int argc,char **argv) {
   t_fourier fourier;
   t_bmp src;
   t_bmp dst;
+  t_bmp cut;
+  int x,y;
+  int offy,offt;
+  int scale;
+  double max;
+  double *mag;
 
   bmp_init(&src,1);
   bmp_init(&dst,1);
+  bmp_init(&cut,1);
   src.mode=READ;
   dst.mode=WRITE;
   strcpy(src.file,argv[1]);
   strcpy(dst.file,argv[2]);
 
+  fourier_init(&fourier,1);
+  fourier.type=DFT|FWD;
+  fourier.dim=2;
+
   bmp_read_file(&src);
 
-  dst.width=src.info.width;
-  dst.height=src.info.height;
+  bmp_cut_grab_bottom(&cut,&src,src.info.width,GRAB);
+
+  dst.width=cut.width;
+  dst.height=cut.height;
   bmp_alloc_map(&dst);
 
-  /* simple copy for testing by now ! */
-  memcpy(dst.map,src.map,src.info.imagesize);
+  fourier.data_len[0]=cut.width;
+  fourier.data_len[1]=cut.height;
+  fourier_alloc_data(&fourier);
+
+  mag=(double *)malloc(fourier.data_len[0]*fourier.data_len[1]*sizeof(double));
+  if(mag==NULL) {
+    printf("unable to alloc mag memory\n");
+    return -1;
+  }
+
+  // copy the data
+  offy=0;
+  for(y=0;y<fourier.data_len[1];y++) {
+    for(x=0;x<fourier.data_len[0];x++) {
+      offt=offy+x;
+      fourier.data[offt].r=(src.map[offt].r+src.map[offt].g+src.map[offt].b)/3;
+    }
+    offy+=fourier.data_len[0];
+  }
+
+  // do the fourier trafo
+  fourier_dft_2d(&fourier);
+
+  printf("fourier done!\n");
+
+  // copy back the data, intensity = sqrt(r^2+i^2)
+  max=0;
+  offt=0;
+  for(y=0;y<fourier.data_len[1];y++) {
+    for(x=0;x<fourier.data_len[0];x++) {
+      mag[offt]=sqrt(fourier.ftdata[offt].r*fourier.ftdata[offt].r+fourier.ftdata[offt].i*fourier.ftdata[offt].i);
+      if(mag[offt]>max) max=mag[offt];
+      offt+=1;
+    }
+  }
+
+  printf("found max: %f\n",max);
+
+  if(max!=0) scale=(int)255/max;
+  else scale=0;
+
+  if(scale!=0) {
+    printf("scaling image intensity: %d\n",scale);
+    offt=0;
+    for(y=0;y<dst.height;y++) {
+      for(x=0;x<dst.width;x++) {
+	// usual image processing order
+        offy=((y<dst.height/2)?y+dst.height/2:y-dst.height/2);
+        offy*=dst.width;
+        offy+=((x<dst.width/2)?x+dst.width/2:x-dst.width/2);
+	//offy=offt;
+        dst.map[offy].r=scale*mag[offt];
+        dst.map[offy].g=dst.map[offy].r;
+        dst.map[offy].b=dst.map[offy].r;
+        offt+=1;
+      }
+    }
+  }
+
+  free(mag);
 
   bmp_write_file(&dst);
 
+  fourier_shutdown(&fourier);
+
   bmp_shutdown(&src);
   bmp_shutdown(&dst);
 
   printf("done ...\n");
 
   return 1;
-
 }