diff --git a/GPU_version/vio/include/vio/cl_class.h b/GPU_version/vio/include/vio/cl_class.h
index bbed7a9..2889f91 100644
--- a/GPU_version/vio/include/vio/cl_class.h
+++ b/GPU_version/vio/include/vio/cl_class.h
@@ -25,57 +25,55 @@ public:
     };
     template<typename T>
     int32_t write(size_t id/*buffer ID*/,T* buf,cl::CommandQueue* queue,cl::Context* context,size_t buf_size){
+        cl_int error;
         _buffers.push_back(std::pair<std::pair<cl::Buffer,size_t>,size_t>(std::pair<cl::Buffer,size_t>(cl::Buffer(*context, CL_MEM_READ_WRITE | CL_MEM_USE_HOST_PTR
-                                                                                                                  , sizeof(T) * buf_size,buf),
+                , sizeof(T) * buf_size,buf,&error),
                                                                                                        buf_size),id));
+        assert(error == CL_SUCCESS);
         cl_int err=_kernel->setArg(id,_buffers.back().first.first);
-        if(err!=0){
-            std::cerr<<"Error C:Kernel, F:write, L3:setArg\t"<<id<<"\t"<<err<<'\n';
-            return err;
-        }
+        assert(err == CL_SUCCESS);
         return CL_SUCCESS;
 
     };
     int32_t write(size_t id/*buffer ID*/,cv::Mat& buf,cl::Context* context){
+        cl_int error;
         _images.push_back(std::pair<cl::Image2D,size_t>(cl::Image2D(*context, CL_MEM_READ_ONLY | CL_MEM_USE_HOST_PTR,
                                                                     cl::ImageFormat(CL_R, CL_UNSIGNED_INT8),
                                                                     buf.size().width,
                                                                     buf.size().height,
                                                                     0,
-                                                                    reinterpret_cast<uchar*>(buf.data)),id));
-
+                                                                    reinterpret_cast<uchar*>(buf.data),&error),id));
+        assert(error == CL_SUCCESS);
         cl_int err=_kernel->setArg(id,_images.back().first);
-        if(err!=0){
-            std::cout<<"Error C:Kernel, F:write image, L:setArg ID:\t"<<id<<"\t"<<err<<'\n';
-            return err;
-        }
+        assert(err == CL_SUCCESS);
         return CL_SUCCESS;
     };
 
     template<typename T>
     int32_t reload(size_t id,T* buf,cl::CommandQueue* queue){
         for(auto&& i:_buffers)if(i.second==id){
-            T* Map_buf=(T*)queue->enqueueMapBuffer(i.first.first,CL_TRUE,CL_MAP_WRITE,0,sizeof(T) * i.first.second);
-            memcpy(Map_buf,buf,sizeof(T) * i.first.second);
-            if(queue->enqueueUnmapMemObject(i.first.first,Map_buf)!=CL_SUCCESS)std::cerr<<"Reload buffer on GPU failed"<<'\n';
+                cl_int error;
+                T* Map_buf=(T*)queue->enqueueMapBuffer(i.first.first,CL_TRUE,CL_MAP_WRITE,0,sizeof(T) * i.first.second,NULL,NULL,&error);
+                assert(error == CL_SUCCESS);
+                memcpy(Map_buf,buf,sizeof(T) * i.first.second);
+                if(queue->enqueueUnmapMemObject(i.first.first,Map_buf)!=CL_SUCCESS)std::cerr<<"Reload buffer on GPU failed"<<'\n';
         }
         return CL_SUCCESS;
     };
     int32_t reload(size_t id,cv::Mat& buf,cl::Context* context){
         try{
             for(auto&& i:_images)if(i.second==id){
-                i.first.setDestructorCallback((void (*)(_cl_mem *, void *))notify, NULL);
+                    cl_int error;
+                    i.first.setDestructorCallback((void (*)(_cl_mem *, void *))notify, NULL);
                     i.first=cl::Image2D(*context, CL_MEM_READ_ONLY | CL_MEM_USE_HOST_PTR,
                                         cl::ImageFormat(CL_R, CL_UNSIGNED_INT8),
                                         buf.size().width,
                                         buf.size().height,
                                         0,
-                                        reinterpret_cast<uchar*>(buf.data));
+                                        reinterpret_cast<uchar*>(buf.data),&error);
+                    assert(error == CL_SUCCESS);
                     cl_int err=_kernel->setArg(id,i.first);
-                    if(err!=0){
-                        std::cerr<<"Error C:Kernel, F:write image, L:setArg ID:\t"<<id<<"\t"<<err<<'\n';
-                        return err;
-                    }
+                    assert(err == CL_SUCCESS);
                 }
             return CL_SUCCESS;
         }catch (std::exception& err){
diff --git a/GPU_version/vio/src/cl_class.cpp b/GPU_version/vio/src/cl_class.cpp
index 0a0b5a3..c3af6a1 100644
--- a/GPU_version/vio/src/cl_class.cpp
+++ b/GPU_version/vio/src/cl_class.cpp
@@ -13,7 +13,7 @@ opencl::opencl(vk::AbstractCamera* cam):cam(cam) {
     std::vector<cl::Device> all_devices;
     for(auto i:all_platforms){
         std::cout << "Find platform number:"<< i.getInfo<CL_PLATFORM_NAME>() << "\n";
-        i.getDevices(CL_DEVICE_TYPE_CPU, &all_devices);
+        i.getDevices(CL_DEVICE_TYPE_GPU, &all_devices);
     }
 
     if (all_devices.size() == 0){
diff --git a/GPU_version/vio/src/frame_handler_mono.cpp b/GPU_version/vio/src/frame_handler_mono.cpp
index b9d9b62..430f051 100644
--- a/GPU_version/vio/src/frame_handler_mono.cpp
+++ b/GPU_version/vio/src/frame_handler_mono.cpp
@@ -167,8 +167,8 @@ FrameHandlerBase::UpdateResult FrameHandlerMono::processFrame()
   new_frame_->T_f_w_=init_f.second;
   new_frame_->Cov_ = init_f.first;
   // sparse image align
-  SparseImgAlign img_align(Config::kltMaxLevel(), Config::kltMinLevel(),30, SparseImgAlign::LevenbergMarquardt, false, false);
-  //SparseImgAlignGpu img_align(Config::kltMaxLevel(), Config::kltMinLevel(),30, SparseImgAlignGpu::GaussNewton, false,gpu_fast_);
+  //SparseImgAlign img_align(Config::kltMaxLevel(), Config::kltMinLevel(),30, SparseImgAlign::LevenbergMarquardt, false, false);
+  SparseImgAlignGpu img_align(Config::kltMaxLevel(), Config::kltMinLevel(),30, SparseImgAlignGpu::GaussNewton, false,gpu_fast_);
   if(img_align.run(last_frame_, new_frame_)==0)return  RESULT_FAILURE;
   //assert (false);
   reprojector_.reprojectMap(new_frame_, overlap_kfs_);