[sift] Remove dead code for extrema search in interpolated DoG planes

Extrema are searched from 3x3x3 blocks of pixels in the DoG pyramid.
The dead code could search in interpolated pixels, which never made sense.
The code was always #undef'ed.

Author: Carsten Griwodz

src/popsift/s_extrema.cu

@@ -579,17 +579,12 @@ void Pyramid::find_extrema( const Config& conf )
 
         int*  num_blocks      = extrema_num_blocks;
 
-#ifdef USE_DOG_TEX_LINEAR
-#define getDogTexture getDogTextureLinear
-#else
-#define getDogTexture getDogTexturePoint
-#endif
         switch( conf.getSiftMode() )
         {
         case Config::VLFeat :
                 find_extrema_in_dog<HEIGHT,Config::VLFeat>
                     <<<grid,block,0,oct_str>>>
-                    ( oct_obj.getDogTexture( ),
+                    ( oct_obj.getDogTexturePoint( ),
                       octave,
                       cols,
                       rows,
@@ -604,7 +599,7 @@ void Pyramid::find_extrema( const Config& conf )
         case Config::OpenCV :
                 find_extrema_in_dog<HEIGHT,Config::OpenCV>
                     <<<grid,block,0,oct_str>>>
-                    ( oct_obj.getDogTexture( ),
+                    ( oct_obj.getDogTexturePoint( ),
                       octave,
                       cols,
                       rows,
@@ -619,7 +614,7 @@ void Pyramid::find_extrema( const Config& conf )
         default :
                 find_extrema_in_dog<HEIGHT,Config::PopSift>
                     <<<grid,block,0,oct_str>>>
-                    ( oct_obj.getDogTexture( ),
+                    ( oct_obj.getDogTexturePoint( ),
                       octave,
                       cols,
                       rows,
@@ -632,7 +627,6 @@ void Pyramid::find_extrema( const Config& conf )
                 POP_SYNC_CHK;
                 break;
         }
-#undef getDogTexture
 
         cuda::event_record( oct_obj.getEventExtremaDone(), oct_str, __FILE__, __LINE__ );
     }

src/popsift/sift_octave.cu

@@ -410,19 +410,12 @@ void Octave::alloc_dog_tex()
 
         err = cudaCreateTextureObject(&_dog_3d_tex_point, &dog_res_desc, &dog_tex_desc, 0);
         POP_CUDA_FATAL_TEST(err, "Could not create DoG texture: ");
-
-        dog_tex_desc.filterMode = cudaFilterModeLinear; // linear interpolation
-        err = cudaCreateTextureObject(&_dog_3d_tex_linear.tex, &dog_res_desc, &dog_tex_desc, 0);
-        POP_CUDA_FATAL_TEST(err, "Could not create DoG texture: ");
 }
 
 void Octave::free_dog_tex()
 {
     cudaError_t err;
 
-    err = cudaDestroyTextureObject(_dog_3d_tex_linear.tex);
-    POP_CUDA_FATAL_TEST(err, "Could not destroy DoG texture: ");
-
     err = cudaDestroyTextureObject(_dog_3d_tex_point);
     POP_CUDA_FATAL_TEST(err, "Could not destroy DoG texture: ");
 

src/popsift/sift_octave.h

@@ -53,7 +53,6 @@ class Octave
     cudaExtent            _dog_3d_ext{};
     cudaSurfaceObject_t   _dog_3d_surf{};
     cudaTextureObject_t   _dog_3d_tex_point{};
-    LinearTexture         _dog_3d_tex_linear{};
 
     // one CUDA stream per level
     // consider whether some of them can be removed
@@ -127,9 +126,6 @@ class Octave
     inline cudaTextureObject_t& getDogTexturePoint( ) {
         return _dog_3d_tex_point;
     }
-    inline LinearTexture& getDogTextureLinear( ) {
-        return _dog_3d_tex_linear;
-    }
 
      /**
       * @brief Allocates all GPU memories for one octave.