diff --git a/GPU_version/vio/src/cl_class.cpp b/GPU_version/vio/src/cl_class.cpp
index c3af6a1..0a0b5a3 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_GPU, &all_devices);
+        i.getDevices(CL_DEVICE_TYPE_CPU, &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 430f051..ff44ab1 100644
--- a/GPU_version/vio/src/frame_handler_mono.cpp
+++ b/GPU_version/vio/src/frame_handler_mono.cpp
@@ -61,8 +61,8 @@ FrameHandlerMono::FrameHandlerMono(vk::AbstractCamera* cam,Eigen::Matrix<double,
     gpu_fast_->write_buf(1,8,9*300,H);
     cl_float3 J[300];
     gpu_fast_->write_buf(1,9,300,J);
-    float chi2[1]={0.01};
-    gpu_fast_->write_buf(1,10,1,chi2);
+    float chi2[300]={0.01};
+    gpu_fast_->write_buf(1,10,300,chi2);
     klt_homography_init_=new initialization::KltHomographyInit(gpu_fast_);
     initialize();
 }