1.makefile中的siftgpu_disable_devil = 1才能成功,不知道会有什么影响…

SLAM拾萃(3)：siftGPU – 半闲居士 – 博客园​ www.cnblogs.com
http://zhaoxuhui.top/blog/2017/05/15/Ubuntu%E4%B8%8BSiftGPU%E6%BA%90%E7%A0%81%E7%BC%96%E8%AF%91.html​ zhaoxuhui.top

2.对于makefile调用siftgpu的库，网上没有介绍的，我采用了

DIR_INC = -I. -I../SiftGPU/src/SiftGPU -I/usr/include -I./opencv2 -I/usr/include/opencv -I/usr/include/opencv2 -I../glew-1.13.0/include -I../opencv-3.2.0/include
DIR_SRC = .
DIR_OBJ = ./build/debug
DIR_LIB =  -L/usr/local/lib -L/usr/lib64  -L../opencv-3.2.0/build/lib -L../glew-1.13.0/lib -L../SiftGPU/bin
#LDFLAGS := -L../SiftGPU/bin/libsiftgpu.so EXECUTABLE := main 

SRC = $(wildcard ${DIR_SRC}/*.cpp)
OBJ = $(patsubst %.cpp,${DIR_OBJ}/%.o,$(notdir ${SRC}))


CC = g++ 
CFLAGS +=-D__STDC_CONSTANT_MACROS -fpermissive -g $(DIR_INC) 

# CFLAGS +=-D__STDC_CONSTANT_MACROS $(DIR_INC) LIB = -lstdc++ ${DIR_LIB} -lX11 -lXi  -lglut -lGL -lGLU -lm -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lavcodec -lavutil -lavformat -lsiftgpu -lopencv_imgcodecs


main:${OBJ}
	$(CC) $(OBJ) $(LIB)  -o $@

${DIR_OBJ}/%.o:${DIR_SRC}/%.cpp
	$(CC) $(CFLAGS)  -c  $< -o $@

clean:
	 rm -rf $(OBJ) $(BIN_PRG)

其中直接链接opencv，opengl，glut，glew，libsiftgpu.so即可，暂时还不是GPU，其中动态链接库的环境变量写入了ld.so.conf，

或者

1. 用ln将需要的so文件链接到/usr/lib或者/lib这两个默认的目录下边

ln -s /where/you/install/lib/*.so /usr/lib
sudo ldconfig

参考了

linux 缺少动态连接库.so–cannot open shared object file: No such file or directory​ www.cnblogs.com

测试代码

https://github.com/RichardYao1995/test_SiftGPU/blob/master/main.cpp​ github.com

更改siftgpu源码：

1.siftgpu.cpp里面含有

 //process the image     _pyramid->RunSIFT(_texImage);

 //read back the timing     _pyramid->GetPyramidTiming(_timing + 2);

 //write output once if there is only one input  if(_outpath[0] ){   SaveSIFT(_outpath); _outpath[0] = 0;}
 
 //terminate the process when -exit is provided.  if(GlobalUtil::_ExitAfterSIFT && GlobalUtil::_UseSiftGPUEX) exit(0); 

指向siftpyramid.cpp的void SiftPyramid::RunSIFT(GLTexInput*input)函数，所以DetectKeypointsEX()是检测关键点的，但是pyramidgl.cpp,pyramidcl.cpp,pyramidcu.cpp都有，先看gl吧。。。cu是cuda 的,cl是opencl的。

programGLSL.h定义了一些关键点，梯度的变量，shaderman.cpp貌似计算？？

这段关键点检测的代码封装的太好了。。需要再看看

void PyramidNaive::DetectKeypointsEX()
{
 int i, j;
 double t0, t, ts, t1, t2;
    GLTexImage * tex, *aux;
    FrameBufferObject fbo;

 if(GlobalUtil::_timingS && GlobalUtil::_verbose)ts = CLOCK();
 
 glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
 //extra gradient data required for visualization
 int gradient_only_levels[2] = {param._level_min +1, param._level_max};
 int n_gradient_only_level = GlobalUtil::_UseSiftGPUEX ? 2 : 1;
 for ( i = _octave_min; i < _octave_min + _octave_num; i++)
    {
 for( j =0; j < n_gradient_only_level ; j++)
        {
            tex = GetLevelTexture(i, gradient_only_levels[j]);
            tex->FitTexViewPort();
            tex->AttachToFBO(0);
            tex->BindTex();
 ShaderMan::UseShaderGradientPass();
            tex->DrawQuadMT4();
        }
    }       

 if(GlobalUtil::_timingS && GlobalUtil::_verbose)
    {
 glFinish();
        t1 = CLOCK();
    }

    GLenum buffers[] = { GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT };
 glDrawBuffers(2, buffers);
 for ( i = _octave_min; i < _octave_min + _octave_num; i++)
    {
 if(GlobalUtil::_timingO)
        {
            t0 = CLOCK();
            std::cout<<"#"<<(i + _down_sample_factor)<<"\t";
        }
        tex = GetBaseLevel(i) + 2;
        aux = GetBaseLevel(i, DATA_KEYPOINT) +2;
        aux->FitTexViewPort();

 for( j = param._level_min + 2; j <  param._level_max ; j++, aux++, tex++)
        {
 if(GlobalUtil::_timingL)t = CLOCK();        
            tex->AttachToFBO(0);
            aux->AttachToFBO(1);
 glActiveTexture(GL_TEXTURE0);
            tex->BindTex();
 glActiveTexture(GL_TEXTURE1);
            (tex+1)->BindTex();
 glActiveTexture(GL_TEXTURE2);
            (tex-1)->BindTex();
 ShaderMan::UseShaderKeypoint((tex+1)->GetTexID(), (tex-1)->GetTexID());
            aux->DrawQuadMT8();
 
 if(GlobalUtil::_timingL)
            {
 glFinish();
                std::cout<<(CLOCK()-t)<<"\t";
            }
            tex->DetachFBO(0);
            aux->DetachFBO(1);
        }
 if(GlobalUtil::_timingO)
        {
            std::cout<<"|\t"<<(CLOCK()-t0)<<"\n";
        }
    }

 if(GlobalUtil::_timingS)
    {
 glFinish();
        t2 = CLOCK();
 if(GlobalUtil::_verbose) 
            std::cout   <<"<Get Keypoints ..  >\t"<<(t2-t1)<<"\n"
 <<"<Extra Gradient..  >\t"<<(t1-ts)<<"\n";
    }
 UnloadProgram();
 GLTexImage::UnbindMultiTex(3);
    fbo.UnattachTex(GL_COLOR_ATTACHMENT1_EXT);


}