SimpleITK  1.3.0.dev466
CSharp/ImageGetBuffer.cs
/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
using System;
using System.Runtime.InteropServices;
using itk.simple;
using PixelId = itk.simple.PixelIDValueEnum;
namespace itk.simple.examples {
public class Program {
static void Main(string[] args) {
if (args.Length < 1) {
Console.WriteLine("Usage: SimpleGaussian <input>");
return;
}
// Read input image
itk.simple.Image input = SimpleITK.ReadImage(args[0]);
// Cast to we know the the pixel type
input = SimpleITK.Cast(input, PixelId.sitkFloat32);
// calculate the number of pixels
VectorUInt32 size = input.GetSize();
int len = 1;
for (int dim = 0; dim < input.GetDimension(); dim++) {
len *= (int)size[dim];
}
IntPtr buffer = input.GetBufferAsFloat();
// There are two ways to access the buffer:
// (1) Access the underlying buffer as a pointer in an "unsafe" block
// (note that in C# "unsafe" simply means that the compiler can not
// perform full type checking), and requires the -unsafe compiler flag
// unsafe {
// float* bufferPtr = (float*)buffer.ToPointer();
// // Now the byte pointer can be accessed as per Brad's email
// // (of course this example is only a 2d single channel image):
// // This is a 1-D array but can be access as a 3-D. Given an
// // image of size [xS,yS,zS], you can access the image at
// // index [x,y,z] as you wish by image[x+y*xS+z*xS*yS],
// // so x is the fastest axis and z is the slowest.
// for (int j = 0; j < size[1]; j++) {
// for (int i = 0; i < size[0]; i++) {
// float pixel = bufferPtr[i + j*size[1]];
// // Do something with pixel here
// }
// }
// }
// (2) Copy the buffer to a "safe" array (i.e. a fully typed array)
// (note that this means memory is duplicated)
float[] bufferAsArray = new float[len]; // Allocates new memory the size of input
Marshal.Copy(buffer, bufferAsArray, 0, len);
double total = 0.0;
for (int j = 0; j < size[1]; j++) {
for (int i = 0; i < size[0]; i++) {
float pixel = bufferAsArray[i + j*size[1]];
total += pixel;
}
}
Console.WriteLine("Pixel value total: {0}", total);
}
}
}