[NI Vision DLL] [C++] [IMAQ DLL] [IMAQ C Support] [Pass image from C to LV] How to Copy raw U16 data to LabVIEW Vision Image Buffer using memcpy()?

[Achuthaperumal]

I have a frame grabber that acquires 16bit grayscale image data as a 1d array of unsigned short. Now I need to convert this raw U16 data to a LabVIEW Vision Image for further processing.

Before proceeding with the actual acquisition, I thought of experimenting with the NI Vision Library Support for C++. I have slightly modified example code from NI to copy a Grayscale U8 image using memcpy(). When I run, for Grayscale U8 , It works.

For the initial test, I created a Grayscale U8 type Image Buffer in LabVIEW and passed the pointer to the Image Handle: 

 

The Parameter Configuration 

 

C++ Function:

#include "nivision.h"

//Image Data as LabVIEW Cluster
typedef struct {
    char* name;
    Image* address;
}IMAQ_Image;

int __stdcall copyImageToLV(IMAQ_Image *LVImage) 
{
  Image* myImage, *lvImage;
  PixelValue pixel;
  ImageInfo myImageInfo, lvImageInfo;
  int y, LVHeight, LVWidth;
  lvImage = LVImage->address;
  pixel.grayscale = 128;
  //Create a New Image buffer and fill it with grey.
  myImage = imaqCreateImage(IMAQ_IMAGE_U8, 3);
  imaqGetImageSize(lvImage, &LVWidth, &LVHeight);
  imaqSetImageSize(myImage, LVWidth, LVHeight);
  imaqFillImage(myImage,pixel, NULL);

  imaqGetImageInfo(myImage, &myImageInfo);
  imaqGetImageInfo(lvImage, &lvImageInfo);
  //LVImage->address = myImage;
  //Copy filled Image to Buffer created from LabVIEW
  for (y = 0; y < LVHeight; ++y)
  {
    memcpy((char *)lvImageInfo.imageStart + y * lvImageInfo.pixelsPerLine,
           (char *)myImageInfo.imageStart + y * myImageInfo.pixelsPerLine, LVWidth);
  }
  imaqDispose(myImage);
  return 0;
}

The Output:

 

Then I tried to implement the same for Grayscale U16 by changing the following lines:

pixel.grayscale = 32000;
myImage = imaqCreateImage(IMAQ_IMAGE_U16, 3);
.
.
.
for(y=0;y<LVHeight;++y){memcpy((unsigned short*)lvImageInfo.imageStart + y * lvImageInfo.pixelsPerLine,
            (unsigned short*)myImageInfo.imageStart + y * myImageInfo.pixelsPerLine, LVWidth);}

I get the following Image with a pixel value of 32000 from 0 to 49th columns and pixel value of 0 from 50 to 99 as output! 

Then I tried the following:

pixel.grayscale = 32000;
myImage = imaqCreateImage(IMAQ_IMAGE_U16, 3);
.
.
.
for(y=0;y<LVHeight*2;++y){  memcpy((char*)lvImageInfo.imageStart + y * lvImageInfo.pixelsPerLine,
            (char*)myImageInfo.imageStart + y * myImageInfo.pixelsPerLine, LVWidth*2);}

I get the following Blank Image with a pixel value of 32000 as output:

I even tried instead of copying the data, I just swapped the address and removing the Dispose part:

LVImage->address = myImage;
//for(y=0;y<LVHeight*2;++y)//{//memcpy((char*)lvImageInfo.imageStart + y * lvImageInfo.pixelsPerLine,
//            (char*)myImageInfo.imageStart + y * myImageInfo.pixelsPerLine, LVWidth*2);
//ImaqDispose(myImage);

Still, I'm getting the same blank Image!

Can anyone help me in copying the data? Any help would be really appreciated... Thanks!