[sift] remove some code that is now dead

Author: Carsten Griwodz

src/popsift/s_pyramid_build.cu

@@ -96,11 +96,7 @@ void make_dog( cudaTextureObject_t src_data,
 __host__
 inline void Pyramid::horiz_from_input_image( const Config& conf, ImageBase* base, cudaStream_t stream )
 {
-    // Variable octave is a leftover of a parameter from the attempt to create
-    // the top level of every octave directly from the upscaled input
-    const int octave = 0;
-
-    Octave&   oct_obj = _octaves[octave];
+    Octave&   oct_obj = _octaves[0];
 
     const int width   = oct_obj.getWidth();
     const int height  = oct_obj.getHeight();
@@ -113,8 +109,8 @@ inline void Pyramid::horiz_from_input_image( const Config& conf, ImageBase* base
     const Config::SiftMode& mode = conf.getSiftMode();
     float shift  = 0.5f;
 
-    if( octave == 0 && ( mode == Config::PopSift || mode == Config::VLFeat ) ) {
-        shift  = 0.5f * powf( 2.0f, conf.getUpscaleFactor() - octave );
+    if( mode == Config::PopSift || mode == Config::VLFeat ) {
+        shift  = 0.5f * powf( 2.0f, conf.getUpscaleFactor() );
     }
 
     gauss::normalizedSource::horiz
@@ -123,7 +119,6 @@ inline void Pyramid::horiz_from_input_image( const Config& conf, ImageBase* base
           oct_obj.getIntermediateSurface(),
           width,
           height,
-          octave,
           shift );
 
     POP_SYNC_CHK;

src/popsift/s_pyramid_build_ra.cu

@@ -19,20 +19,15 @@ void horiz( cudaTextureObject_t src_linear_tex,
             cudaSurfaceObject_t dst_data,
             int                 dst_w,
             int                 dst_h,
-            int                 octave,
             float               shift )
 {
-    // Create level-0 for the first octave from the input image.
-    // TODO: octave is always 0
-    //       remove the unused levels of d_gauss.dd.span and d_gauss.dd.filter
-
     const int    write_x = blockIdx.x * blockDim.x + threadIdx.x;
     const int    write_y = blockIdx.y;
 
     if( write_x >= dst_w ) return;
 
-    const int    span    =  d_gauss.dd.span[octave];
-    const float* filter  = &d_gauss.dd.filter[octave*GAUSS_ALIGN];
+    const int    span    =  d_gauss.dd.span[0];
+    const float* filter  = &d_gauss.dd.filter[0];
     const float  read_x  = ( blockIdx.x * blockDim.x + threadIdx.x + shift ) / dst_w;
     const float  read_y  = ( blockIdx.y + shift ) / dst_h;
 

src/popsift/s_pyramid_build_ra.h

@@ -15,7 +15,6 @@ __global__ void horiz(cudaTextureObject_t src_data,
                       cudaSurfaceObject_t dst_data,
                       int dst_w,
                       int dst_h,
-                      int octave,
                       float shift);
 
 __global__ void horiz_level(cudaTextureObject_t src_linear_tex,