NI_ex1_Acquisition.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

using NationalInstruments.Vision;
using NationalInstruments.Vision.Acquisition.Imaq;

namespace StroboR3
{
    class Acquisition
    {
        private ImaqSession _session = null;
        private ImaqBufferCollection bufList;
        private PixelValue2D subPixels;

        private int[] dims;
        private string interfaceName;
        private uint bufferNumber;
        private int numberOfImages;    // buffer size
        private int imageNumPerSet;          // z axis of imageData

        public Acquisition()
        {
            // Initialize
            dims = new int[] { 640, 480, 40 };
            interfaceName = "img0";
            numberOfImages = 5;
            bufferNumber = 1; // start from 1, see ImaqAcquisition.Extract help page
            imageNumPerSet = 0;

            //  Create a session.
            _session = new ImaqSession(interfaceName);
            subPixels = new PixelValue2D(new byte[dims[1], dims[0]]);
        }

        public void Setup()
        {
            //  Create a buffer collection for the acquisition with the requested
            //  number of images, and configure the buffers to loop continuously.
            bufList = _session.CreateBufferCollection(numberOfImages, ImaqBufferCollectionType.PixelValue2D);
            for (int i = 0; i < bufList.Count; ++i)
            {
                bufList[i].Command = (i == bufList.Count - 1) ? ImaqBufferCommand.Loop : ImaqBufferCommand.Next;
            }
            //  Configure and start the acquisition.
            _session.Acquisition.Configure(bufList);
            _session.Acquisition.AcquireAsync();
        }

        public void Run(VisionImage curImage, VisionImage subImage)
        {
            uint curBufferNumber, preBufferNumber;
            PixelValue2D curPixels = _session.Acquisition.Extract(bufferNumber, out curBufferNumber).ToPixelArray();
            PixelValue2D prePixels = _session.Acquisition.Extract(bufferNumber-1, out preBufferNumber).ToPixelArray();

            //  Check curBufferNumber and preBufferNumber?

            //  Subtraction and Save
            float[] pixel = new float[] { 0.0f };
            IntPtr pPixel;
            int tmp;
            for (int y = 0; y < dims[1]; y++)
            {
                for (int x = 0; x < dims[0]; x++)
                {
                    tmp = (int)curPixels.U8[y, x] - (int)prePixels.U8[y, x];
                    tmp = (tmp < 0) ? -tmp : tmp;
                    //  Set subPixels to display subtraction image
                    subPixels.U8[y, x] = (byte)tmp;
                }
            }
            imageNumPerSet++;

            //  Display
            curImage.ArrayToImage(curPixels);
            subImage.ArrayToImage(subPixels);
        }

        public void Stop()
        {
            _session.Stop();
        }

        public void Close()
        {
            _session.Close();
        }
    }