ImageDev

Data Transfer

This example illustrates how to create a data buffer corresponding to a 3D image, and transfer it in an object connectable to an ImageDev algorithm, without duplicating the data.
To invoke an ImageDev algorithm, the data to process needs to be previously imported into an ImageView object of the IOLink library.

The two previous examples show how to create an ImageView from an existing buffer by copying the data. This way to proceed is safe and prevents conflicts of data ownership. However, when handling large data, it may be preferable to make the ImageView object directly point to the buffer without duplicating its content.

The first part of this example simply creates a buffer representing a 220x192x128 pixel image with a filled sphere drawn inside. This step is for demonstration purposes only. In practice, you should already have the content of the image to process in a buffer stored in the data model used by your application.

Then some IOLink instructions create a new ImageView object. The buffer previously created is set in this image with the fromBuffer method of the ImageViewFactory class. This method does not duplicate the data, thus optimizing the memory usage.

Two ImageDev algorithms are applied afterward to show that it is now possible to process this image with ImageDev.
<b>Figure 1.</b> The 3D volume generated by this example visualized with Open Inventor
Figure 1. The 3D volume generated by this example visualized with Open Inventor

Note:
The last operator adds the values of an 8-bit signed integer image to those of an 8-bit unsigned integer image. The result is a 16-bit signed integer image, as explained in the Basic Rule table of the Rules for Arithmetic Image Type section.

#include <ImageDev/Data/ImageViewHelper.h>
#include <ImageDev/ImageDev.h>
#include <ioformat/IOFormat.h>
#include <iolink/view/ImageViewFactory.h>
#include <iolink/view/ImageViewProvider.h>

using namespace imagedev;
using namespace ioformat;
using namespace iolink;

int
main()
{
    // ImageDev library initialization
    if ( imagedev::isInitialized() == false )
        imagedev::init();

    // Initialize an unsigned 8-bit array storing data of a 3D image
    const uint64_t rowCount = 220;
    const uint64_t colCount = 192;
    const uint64_t sliCount = 128;
    std::vector< uint8_t > imageData( rowCount * colCount * sliCount );

    // Define a synthetic sphere in this array
    const int squareRadius = ( sliCount / 2 - 10 ) * ( sliCount / 2 - 10 ); // Radius of the sphere to draw
    int distToCenter;

    // Loop on image slices
    for ( int k = 0; k < sliCount; ++k )
    {
        // Loop on image rows
        for ( int i = 0; i < rowCount; ++i )
        {
            // Loop on image columns
            for ( int j = 0; j < colCount; ++j )
            {
                distToCenter = ( i - rowCount / 2 ) * ( i - rowCount / 2 ) +
                               ( j - colCount / 2 ) * ( j - colCount / 2 ) +
                               ( k - sliCount / 2 ) * ( k - sliCount / 2 );
                if ( distToCenter <= squareRadius )
                    imageData[k * rowCount * colCount + i * colCount + j] = 200; // Value inside the sphere
                else
                    imageData[k * rowCount * colCount + i * colCount + j] = 0; // Background value
            }
        }
    }

    // Create an image view of same dimensions directly from this buffer
    VectorXu64 imageShape{ colCount, rowCount, sliCount };
    auto image = ImageViewFactory::fromBuffer(
        imageShape, DataTypeId::UINT8, imageData.data(), rowCount * colCount * sliCount * sizeof( uint8_t ) );
    setDimensionalInterpretation( image, ImageTypeId::VOLUME );

    // This image can now be processed by any ImageDev algorithm, for instance to add a Gaussian noise inside
    auto imageNoise = randomGaussianImage3d(
        RandomGaussianImage3d::OutputType::SIGNED_INTEGER_8_BIT, colCount, rowCount, sliCount, 0.0f, 20.0f );
    auto imageOut =
        arithmeticOperationWithImage( image, imageNoise, ArithmeticOperationWithImage::ArithmeticOperator::ADD );

    // Save the created image with IOFormat
    writeView( imageOut, R"(T02_03_output.tif)" );

    // ImageDev library finalization
    imagedev::finish();

    return 0;
}
using System;
using ImageDev;
using IOLink;
using IOFormat;

namespace T02_03_TransferData
{
    class Program
    {
        static void Main( string[] args )
        {
            // Initialize the ImageDev library if not done
            if ( Initialization.IsInitialized() == false )
                Initialization.Init();

            // Initialize an unsigned 8-bit array storing data of a 3D image
            int rowCount = 220;
            int colCount = 192;
            int sliCount = 128;
            byte[] imageData = new byte[rowCount * colCount * sliCount];

            // Define a synthetic sphere in this array
            int squareRadius = ( sliCount / 2 - 10 ) * ( sliCount / 2 - 10 ); // Radius of the sphere to draw
            int distToCenter;

            // Loop on image slices
            for ( int k = 0; k < sliCount; ++k )
            {
                // Loop on image rows
                for ( int i = 0; i < rowCount; ++i )
                {
                    // Loop on image columns
                    for ( int j = 0; j < colCount; ++j )
                    {
                        distToCenter = ( i - rowCount / 2 ) * ( i - rowCount / 2 ) +
                                       ( j - colCount / 2 ) * ( j - colCount / 2 ) +
                                       ( k - sliCount / 2 ) * ( k - sliCount / 2 );
                        if ( distToCenter <= squareRadius )
                            imageData[k * rowCount * colCount + i * colCount + j] = 200; // Value inside the sphere
                        else
                            imageData[k * rowCount * colCount + i * colCount + j] = 0; // Background value
                    }
                }
            }

            // Create an image view of same dimensions
            VectorXu64 imageShape = new VectorXu64( ( ulong )colCount, ( ulong )rowCount, ( ulong )sliCount );
            ImageView image = ImageViewFactory.FromBuffer(
                imageShape, DataTypeId.UINT8, imageData, ( uint )( rowCount * colCount * sliCount * sizeof( byte ) ) );
            Data.SetDimensionalInterpretation( image, ImageTypeId.VOLUME );

            // This image can now be processed by any ImageDev algorithm, for instance to add a Gaussian noise inside
            ImageView imageNoise = Processing.RandomGaussianImage3d(
                RandomGaussianImage3d.OutputType.SIGNED_INTEGER_8_BIT, colCount, rowCount, sliCount, 0.0f, 20.0f );
            ImageView imageOut = Processing.ArithmeticOperationWithImage(
                image, imageNoise, ArithmeticOperationWithImage.ArithmeticOperator.ADD );

            // Save the created image with IOFormat
            ViewIO.WriteView( imageOut, @"T02_03_output.tif" );

            // ImageDev library finalization
            Initialization.Finish();
        }
    }
}
import imagedev
import iolink
import ioformat
import numpy

# Initialize the ImageDev library if not done
if (imagedev.is_initialized() == False): imagedev.init()

# Initialize an unsigned 8-bit three-dimensional numpy array storing data of a 3D image
row_count = 220
col_count = 192
sli_count = 128
image_data = numpy.zeros((sli_count, row_count, col_count), numpy.uint8)

# Define a synthetic sphere in this array
# Define the sphere center and radius value
center = (int(sli_count/2), int(row_count/2), int(col_count/2))
radius = int(sli_count/2) - 10

# Create a distance map image with origin the sphere center
slice_grid, row_grid, col_grid = numpy.ogrid[:sli_count, :row_count, :col_count]
dist_from_center = numpy.sqrt((slice_grid - center[0])**2 + (row_grid-center[1])**2 + (col_grid-center[2])**2)

# Mask the distance map where values are greater than the radius value
mask = dist_from_center <= radius
image_data[mask] = 200

# Transform the Numpy array into an ImageView of same dimensions and type
image = iolink.NumpyInterop.from_numpy_array(image_data, iolink.ImageTypeId.VOLUME)

# This image can now be processed by any ImageDev algorithm, for instance to add a Gaussian noise inside
image_noise = imagedev.random_gaussian_image_3d(
  imagedev.RandomGaussianImage3d.OutputType.SIGNED_INTEGER_8_BIT, col_count, row_count, sli_count, 0.0, 20.0)
image_out = imagedev.arithmetic_operation_with_image(
  image, image_noise, imagedev.ArithmeticOperationWithImage.ArithmeticOperator.ADD)

# Save the created image with IOFormat
ioformat.write_view(image_out, "T02_03_output.tif")

# ImageDev library finalization
imagedev.finish()


See also