[refactor] Replace sift_roi binary by shared library and ctypes

.travis.yml

@@ -25,11 +25,11 @@ before_install:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew unlink gdal && (brew install gcc || brew link --overwrite gcc) && brew install geographiclib fftw; fi
 
 install:
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then pip install numpy utm bs4 requests; fi
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then pip install numpy rasterio utm bs4 requests; fi
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then pip install GDAL==$(gdal-config --version | awk -F'[.]' '{print $1"."$2}'); fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then wget http://www.kyngchaos.com/files/software/frameworks/GDAL_Complete-2.1.dmg; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then X=$(echo `hdiutil mount GDAL_Complete-2.1.dmg | tail -1 | awk '{$1=$2=""; print $0}'` | xargs -0 echo) && sudo installer -pkg "${X}/"GDAL\ Complete.pkg -target /; export PATH="/Library/Frameworks/GDAL.framework/Programs:$PATH"; fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then pip2 install numpy utm bs4 requests; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then pip2 install numpy rasterio utm bs4 requests; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then pip2 install GDAL==$(gdal-config --version | awk -F'[.]' '{print $1"."$2}') --global-option build_ext --global-option=`gdal-config --cflags` --global-option build_ext --global-option=-L`gdal-config  --prefix`/unix/lib/; fi
 
 script:

README.md

@@ -74,7 +74,7 @@ Required dependencies (Ubuntu 16.04):
 
 and
 
-    pip install utm bs4 lxml requests
+    pip install utm bs4 lxml requests rasterio
 
 `gdal` version must be 2.1.0 or newer.
 

c/sift/Makefile

@@ -1,10 +1,9 @@
 CXXFLAGS ?= -march=native -O3
-override CXXFLAGS := $(CXXFLAGS) `gdal-config --cflags`
-override CXXLIBS  := $(CXXLIBS)  `gdal-config --libs`
+override CXXFLAGS := $(CXXFLAGS) -fPIC
+override CXXLIBS  := $(CXXLIBS)
 override LDLIBS   := $(LDLIBS) -lm
 
-OBJ = sift_roi.o \
-      LibImages/LibImages.o \
+OBJ = LibImages/LibImages.o \
       LibSSE/LibSSE.o \
       LibSift/KeyPoint.o \
       LibSift/LibSift.o \
@@ -13,12 +12,15 @@ OBJ = sift_roi.o \
       Utilities/Memory.o \
       Utilities/Parameters.o \
       Utilities/Time.o \
-      Utilities/Utilities.o \
+      Utilities/Utilities.o\
+      sift4ctypes.o \
 
-all: sift_roi matching
+LIB = libsift4ctypes.so
 
-sift_roi: $(OBJ)
-	$(CXX) -o $@ $^ $(CXXLIBS)
+all: $(LIB) matching
+
+$(LIB): $(OBJ)
+	$(CXX) -fPIC -shared -o $@ $^
 
 clean:
-	rm -f sift_roi matching $(OBJ)
+	rm -f $(LIB) matching $(OBJ)

c/sift/sift4ctypes.cpp

@@ -0,0 +1,80 @@
+// Copyright (C) 2019, Julien Michel (CNES) <[email protected]>
+
+#include <stdlib.h>
+
+#include "Utilities/Parameters.h"
+#include "LibImages/LibImages.h"
+#include "LibSift/LibSift.h"
+
+extern "C"{
+  /**
+   * This function is meant to be mapped to python using ctypes.
+   * 
+   * It computes sifts points of input_buffer which is interpreted as a w x h image.
+   * Keypoints are returned as a linear buffer of float of size recordSize * nbRecords. 
+   * 
+   * This buffer is the responsibiliy of the caller and should be freed by her.
+   */
+  float * sift(const float * input_buffer, const size_t w, const size_t h, 
+	       const float thresh_dog, 
+	       const unsigned int ss_noct, 
+	       const unsigned int ss_nspo,
+	       unsigned int & recordSize,
+	       unsigned int & nbRecords) {
+
+    // Derive Image from buffer
+    Image im(input_buffer, (const size_t) w, (const size_t) h, 1);
+
+    // prepare params object
+    Parameters params;
+    params.setDefaultValues();
+    params.set_thresh_dog(thresh_dog);
+    params.set_noct(ss_noct);
+    params.set_nspo(ss_nspo);
+
+    // run sift
+    Sift sift(params);
+    sift.computeKeyPoints(im);
+
+    // Compute the number of records
+    nbRecords = sift.m_keyPoints->size();
+
+    // Compute the record length
+    size_t descriptorSize = 0;
+    if(nbRecords > 0)
+    {
+        const KeyPoint * firstPoint = sift.m_keyPoints->front();
+        descriptorSize = firstPoint->getNbOri() * firstPoint->getNbHist() * firstPoint->getNbHist();
+    }
+    recordSize = descriptorSize + 4;
+
+    // Allocate output buffer
+    float * out = new float[recordSize*nbRecords];
+
+    // Fill output buffer with keypoints
+    std::list<KeyPoint*>::iterator key = sift.m_keyPoints->begin();
+    size_t currentPoint  = 0;
+    for(;key != sift.m_keyPoints->end();++key,++currentPoint)
+    {
+        size_t currentIndex = recordSize*currentPoint;
+        out[currentIndex] = (*key)->getY();
+        out[currentIndex+1] = (*key)->getX();
+	out[currentIndex+2] = (*key)->getSigma();
+	out[currentIndex+3] = (*key)->getTheta();
+        for(unsigned int i = 0; i < descriptorSize;++i)
+        {
+            out[currentIndex+4+i] = (*key)->getPtrDescr()[i];
+        } 
+    }   
+    return out;
+  }
+  /**
+   * This function allows to free the float buffer from python.
+  */
+  void delete_buffer(float * buffer)
+  {
+    if (buffer != NULL)
+      delete [] buffer;
+  }
+
+}

makefile

@@ -21,9 +21,10 @@ endif
 # names of source and destination directories
 SRCDIR = c
 BINDIR = bin
+LIBDIR = lib
 
 # default rule builds only the programs necessary for the test
-default: $(BINDIR) homography sift imscript mgm mgm_multi piio tvl1 lsd
+default: $(BINDIR) $(LIBDIR) homography sift imscript mgm mgm_multi piio tvl1 lsd
 
 # the "all" rule builds four further correlators
 all: default msmw3 sgbm mgm_multi
@@ -35,6 +36,8 @@ test: default
 # make sure that the destination directory is built
 $(BINDIR):
 	mkdir -p $(BINDIR)
+$(LIBDIR):
+	mkdir -p $(LIBDIR)
 
 #
 # four standard "modules": homography, sift, mgm, and mgm_multi
@@ -46,9 +49,8 @@ homography: $(BINDIR)
 
 sift: $(BINDIR)
 	$(MAKE) -j -C c/sift
-	cp c/sift/sift_roi $(BINDIR)
-	cp c/sift/matching $(BINDIR)
-
+	cp c/sift/libsift4ctypes.so $(LIBDIR)
+	cp c/sift/matching ${BINDIR}
 mgm:
 	$(MAKE) -C 3rdparty/mgm
 	#cp 3rdparty/mgm/mgm $(BINDIR)
@@ -195,7 +197,7 @@ clean_homography:
 
 clean_sift:
 	$(MAKE) -C c/sift clean
-	$(RM) $(BINDIR)/sift_roi
+	$(RM) $(LIBDIR)/libsift4ctypes.so
 	$(RM) $(BINDIR)/matching
 
 clean_asift:

s2p_test.py

@@ -60,24 +60,24 @@ def unit_image_keypoints():
     for i in range(test_kpts.shape[0]):
         found = False
         for j in range(ref_kpts.shape[0]):
-            dist = np.linalg.norm(test_kpts[i,0:1]-ref_kpts[j,0:1])
+            dist = np.linalg.norm(test_kpts[i,0:2]-ref_kpts[j,0:2])
             if dist<dist_tol:
                 found = True
         if not found:
-            print("KeyPoint not found: "+str((test_kpts[i,0:1])))
+            print("KeyPoint not found: "+str((test_kpts[i,0:2])))
             nb_test_not_in_ref+=1
 
     print(str(nb_test_not_in_ref)+" test kpts have no spatially close match in ref")
 
     nb_ref_not_in_test = 0
-    for i in range(test_kpts.shape[0]):
+    for i in range(ref_kpts.shape[0]):
         found = False
-        for j in range(ref_kpts.shape[0]):
-            dist = np.linalg.norm(test_kpts[i,0:1]-ref_kpts[j,0:1])
+        for j in range(test_kpts.shape[0]):
+            dist = np.linalg.norm(ref_kpts[i,0:2]-test_kpts[j,0:2])
             if dist<dist_tol:
                 found = True
         if not found:
-            print("KeyPoint not found: "+str((test_kpts[i,0:1])))
+            print("KeyPoint not found: "+str((test_kpts[i,0:2])))
             nb_ref_not_in_test+=1
 
     print(str(nb_ref_not_in_test)+" ref kpts have no spatially close match in test")