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asked 2012-09-20 11:55:57 -0600

bharath422 gravatar image

GPU Code Not Working Question

Hi,

(This is a continuation from the post "Pseudocode for custom GPU computation")

Following is my GPU opencv code. I tried 2 things - 1) to just set all pixels of the output to zero, 2) return a monochrome image based on a threshold on the pixel values of the input image. But for both cases when I run it, I dont get the result I want, I get some grayscale image, which is just peppered noise. My code below:

//The size of the video frame is 480 * 640

//funcam.cpp

using namespace std;

using namespace cv;

using namespace cv::gpu;

void callKernel(const GpuMat& src, const GpuMat& dst)

{

uchar* p = src.data;

uchar* p2 = dst.data;

func(p, p2, src.step, src.cols, src.rows, dst.step);

}

int main(int, char**) {

VideoCapture cap(0);

if(!cap.isOpened()) return -1;

int frameH = (int) cap.get(CV_CAP_PROP_FRAME_HEIGHT);

int frameW = (int) cap.get(CV_CAP_PROP_FRAME_WIDTH);

cout << frameH << " " << frameW << endl;

CvSize size = cvSize(frameH, frameW);

Mat frame;

Mat input;

Mat output;

GpuMat d_frame;

GpuMat d_output;

for(;;)

{

  cap >> frame;

  if (frame.empty())

     break;

  //convert to grayscale

  cvtColor(frame, input, CV_BGR2GRAY);

  // memory Copy from Host to Device

  d_frame.upload(input);

  // Call CUDA kernel

  d_output.create(size, CV_8UC1);

  callKernel(d_frame, d_output);

  // memory Copy from Device to Host

  d_output.download(output);

  imshow("output", output);

  if(waitKey(30) >= 0)

     break;

}

return 0;

}

//funcam_cuda.cu

__global__ void funcKernel(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep)

{

int rowInd = blockIdx.y * blockDim.y + threadIdx.y;

int colInd = blockIdx.x * blockDim.x + threadIdx.x;

uchar* rowsrcPtr = srcptr + rowInd*step;

uchar* rowdstPtr = dstptr + rowInd*dststep;

uchar pixVal = rowsrcPtr[colInd];

// rowdstPtr[colInd] = (pixVal > 60 ? 255 : 0);

rowdstPtr[colInd] = 0;

}

extern "C"

void func(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) {

dim3 grDim (16, 12);

dim3 blDim (40, 40);

funcKernel<<< grDim, blDim >>>(srcptr, dstptr, step, cols, rows, dststep);

cudaThreadSynchronize(); //Is this reqd?

}

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improved style

updated 2012-09-20 12:42:53 -0600

Daniil Osokin gravatar image

GPU Code Not Working Question

Hi,

(This is a continuation from the post "Pseudocode for custom GPU computation")computation")

Following is my GPU opencv code. I tried 2 things - 1) to just set all pixels of the output to zero, 2) return a monochrome image based on a threshold on the pixel values of the input image. But for both cases when I run it, I dont get the result I want, I get some grayscale image, which is just peppered noise. My code below:

 //The size of the video frame is 480 * 640
 
//funcam.cpp
 
640

//funcam.cpp

using namespace std;
 
std;

using namespace cv;
 
cv;

using namespace cv::gpu;
 
cv::gpu;


void callKernel(const GpuMat& src, const GpuMat& dst)
 
{
 
dst)

{

   uchar* p = src.data;
 
src.data;

   uchar* p2 = dst.data;
 
dst.data;

   func(p, p2, src.step, src.cols, src.rows, dst.step);
 
}
 
dst.step);

}


int main(int, char**) 
{
 
{

   VideoCapture cap(0);
 
cap(0);

   if(!cap.isOpened()) return -1;
 
-1;


   int frameH    = (int) cap.get(CV_CAP_PROP_FRAME_HEIGHT);
 
cap.get(CV_CAP_PROP_FRAME_HEIGHT);

   int frameW    = (int) cap.get(CV_CAP_PROP_FRAME_WIDTH);
 
cap.get(CV_CAP_PROP_FRAME_WIDTH);

   cout << frameH << " " << frameW << endl;
 
endl;

   CvSize size = cvSize(frameH, frameW);
 
frameW);

   Mat frame;
 
frame;

   Mat input;
 
input;

   Mat output;
 
output;

   GpuMat d_frame;
 
d_frame;

   GpuMat d_output;
 
for(;;)
 
{
 
d_output;

   for(;;)

   {

      cap >> frame;

   if (frame.empty())

      break;

   //convert to grayscale

   cvtColor(frame, input, CV_BGR2GRAY);

   // memory Copy from Host to Device

   d_frame.upload(input);

   // Call CUDA kernel

   d_output.create(size, CV_8UC1);

   callKernel(d_frame, d_output);

   // memory Copy from Device to Host

   d_output.download(output);

   imshow("output", output);

   if(waitKey(30) >= 0)

      break;

 
}
 
   }

    return 0;

 
}
 
//funcam_cuda.cu
 

}


//funcam_cuda.cu

__global__ void funcKernel(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) 
 
{
 


{

   int rowInd = blockIdx.y * blockDim.y + threadIdx.y;
 
threadIdx.y;

   int colInd = blockIdx.x * blockDim.x + threadIdx.x;
 
threadIdx.x;

   uchar* rowsrcPtr = srcptr + rowInd*step;
 
rowInd*step;

   uchar* rowdstPtr = dstptr + rowInd*dststep;
 
rowInd*dststep;

   uchar pixVal = rowsrcPtr[colInd];
 
rowsrcPtr[colInd];

// rowdstPtr[colInd] = (pixVal > 60 ? 255 : 0);
 
0);

   rowdstPtr[colInd] = 0;
 
}
 
0;

}

extern "C"
 
"C"

void func(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) {
 
{

dim3 grDim (16, 12);
 
12);

dim3 blDim (40, 40);
 
40);

funcKernel<<< grDim, blDim >>>(srcptr, dstptr, step, cols, rows, dststep);
 
dststep);

cudaThreadSynchronize(); //Is this reqd?
 
reqd?

}
click to hide/show revision 3
formatting

updated 2012-09-21 01:16:30 -0600

Andrey Pavlenko gravatar image

GPU Code Not Working Question

Hi,

(This is a continuation from the post "Pseudocode for custom GPU computation")

Following is my GPU opencv code. I tried 2 things - 1) to just set all pixels of the output to zero, 2) return a monochrome image based on a threshold on the pixel values of the input image. But for both cases when I run it, I dont get the result I want, I get some grayscale image, which is just peppered noise. My code below:


//The size of the video frame is 480 * 640
 //funcam.cpp

using namespace std;
 using namespace cv;
 using namespace cv::gpu;
 
void callKernel(const GpuMat& src, const GpuMat& dst)
 {
    uchar* p = src.data;
    uchar* p2 = dst.data;
    func(p, p2, src.step, src.cols, src.rows, dst.step);
 }
 
int main(int, char**) 
{
    VideoCapture cap(0);
    if(!cap.isOpened()) return -1;

    int frameH    = (int) cap.get(CV_CAP_PROP_FRAME_HEIGHT);
    int frameW    = (int) cap.get(CV_CAP_PROP_FRAME_WIDTH);
    cout << frameH << " " << frameW << endl;

   CvSize size = cvSize(frameH, frameW);
    Mat frame;
    Mat input;
    Mat output;
    GpuMat d_frame;
    GpuMat d_output;

   for(;;)
    {
       cap >> frame;
       if (frame.empty())
          break;

      //convert to grayscale
       cvtColor(frame, input, CV_BGR2GRAY);

      // memory Copy from Host to Device
       d_frame.upload(input);

      // Call CUDA kernel
       d_output.create(size, CV_8UC1);
       callKernel(d_frame, d_output);

      // memory Copy from Device to Host
       d_output.download(output);

      imshow("output", output);
       if(waitKey(30) >= 0)
          break;
   }
     return 0;
 }

 //funcam_cuda.cu
 __global__ void funcKernel(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) 
 {
    int rowInd = blockIdx.y * blockDim.y + threadIdx.y;
    int colInd = blockIdx.x * blockDim.x + threadIdx.x;
    uchar* rowsrcPtr = srcptr + rowInd*step;
    uchar* rowdstPtr = dstptr + rowInd*dststep;
    uchar pixVal = rowsrcPtr[colInd];
 // rowdstPtr[colInd] = (pixVal > 60 ? 255 : 0);
    rowdstPtr[colInd] = 0;
 }

extern "C"
 void func(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) dststep)
{
 dim3 grDim (16, 12);
 dim3 blDim (40, 40);
 funcKernel<<< grDim, blDim >>>(srcptr, dstptr, step, cols, rows, dststep);
 cudaThreadSynchronize(); //Is this reqd?

}}
click to hide/show revision 4
retagged

updated 2012-09-21 08:14:28 -0600

Kirill Kornyakov gravatar image

GPU Code Not Working Question

Hi,

(This is a continuation from the post "Pseudocode for custom GPU computation")

Following is my GPU opencv code. I tried 2 things - 1) to just set all pixels of the output to zero, 2) return a monochrome image based on a threshold on the pixel values of the input image. But for both cases when I run it, I dont get the result I want, I get some grayscale image, which is just peppered noise. My code below:


//The size of the video frame is 480 * 640
//funcam.cpp

using namespace std;
using namespace cv;
using namespace cv::gpu;

void callKernel(const GpuMat& src, const GpuMat& dst)
{
   uchar* p = src.data;
   uchar* p2 = dst.data;
   func(p, p2, src.step, src.cols, src.rows, dst.step);
}

int main(int, char**) 
{
   VideoCapture cap(0);
   if(!cap.isOpened()) return -1;

   int frameH    = (int) cap.get(CV_CAP_PROP_FRAME_HEIGHT);
   int frameW    = (int) cap.get(CV_CAP_PROP_FRAME_WIDTH);
   cout << frameH << " " << frameW << endl;

   CvSize size = cvSize(frameH, frameW);
   Mat frame;
   Mat input;
   Mat output;
   GpuMat d_frame;
   GpuMat d_output;

   for(;;)
   {
      cap >> frame;
      if (frame.empty())
         break;

      //convert to grayscale
      cvtColor(frame, input, CV_BGR2GRAY);

      // memory Copy from Host to Device
      d_frame.upload(input);

      // Call CUDA kernel
      d_output.create(size, CV_8UC1);
      callKernel(d_frame, d_output);

      // memory Copy from Device to Host
      d_output.download(output);

      imshow("output", output);
      if(waitKey(30) >= 0)
         break;
   }
    return 0;
}

//funcam_cuda.cu
__global__ void funcKernel(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep) 
{
   int rowInd = blockIdx.y * blockDim.y + threadIdx.y;
   int colInd = blockIdx.x * blockDim.x + threadIdx.x;
   uchar* rowsrcPtr = srcptr + rowInd*step;
   uchar* rowdstPtr = dstptr + rowInd*dststep;
   uchar pixVal = rowsrcPtr[colInd];
// rowdstPtr[colInd] = (pixVal > 60 ? 255 : 0);
   rowdstPtr[colInd] = 0;
}

extern "C"
void func(uchar* srcptr, uchar* dstptr, int step, int cols, int rows, int dststep)
{
dim3 grDim (16, 12);
dim3 blDim (40, 40);
funcKernel<<< grDim, blDim >>>(srcptr, dstptr, step, cols, rows, dststep);
cudaThreadSynchronize(); //Is this reqd?
}
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