Complex image.
The class is used to keep image represented in complex numbers sutable for Fourier transformations.
Sample usage:
// create complex image ComplexImage complexImage = ComplexImage.FromBitmap( image ); // do forward Fourier transformation complexImage.ForwardFourierTransform( ); // get complex image as bitmat Bitmap fourierImage = complexImage.ToBitmap( ); Initial image:
Fourier image:
/// <summary>
/// Create complex image from grayscale bitmap.
/// </summary>
///
/// <param name="imageData">Source image data (8 bpp indexed).</param>
///
/// <returns>Returns an instance of complex image.</returns>
///
/// <exception cref="UnsupportedImageFormatException">The source image has incorrect pixel format.</exception>
/// <exception cref="InvalidImagePropertiesException">Image width and height should be power of 2.</exception>
///
public static ComplexImage FromBitmap(BitmapData imageData)
{
// check image format
if (imageData.PixelFormat != PixelFormat.Format8bppIndexed)
{
throw new UnsupportedImageFormatException("Source image can be graysclae (8bpp indexed) image only.");
}
// get source image size
int width = imageData.Width;
int height = imageData.Height;
int offset = imageData.Stride - width;
// check image size
if ((!Accord.Math.Tools.IsPowerOf2(width)) || (!Accord.Math.Tools.IsPowerOf2(height)))
{
throw new InvalidImagePropertiesException("Image width and height should be power of 2.");
}
// create new complex image
ComplexImage complexImage = new ComplexImage(width, height);
Complex[,] data = complexImage.data;
// do the job
unsafe
{
byte *src = (byte *)imageData.Scan0.ToPointer();
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, src++)
{
data[y, x] = new Complex((float)*src / 255, data[y, x].Imaginary);
}
src += offset;
}
}
return(complexImage);
}
/// <summary>
/// Clone the complex image.
/// </summary>
///
/// <returns>Returns copy of the complex image.</returns>
///
public object Clone()
{
// create new complex image
ComplexImage dstImage = new ComplexImage(width, height);
Complex[,] data = dstImage.data;
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
data[i, j] = this.data[i, j];
}
}
// clone mode as well
dstImage.fourierTransformed = fourierTransformed;
return(dstImage);
}
/// <summary>
/// Create complex image from grayscale bitmap.
/// </summary>
///
/// <param name="imageData">Source image data (8 bpp indexed).</param>
///
/// <returns>Returns an instance of complex image.</returns>
///
/// <exception cref="UnsupportedImageFormatException">The source image has incorrect pixel format.</exception>
/// <exception cref="InvalidImagePropertiesException">Image width and height should be power of 2.</exception>
///
public static ComplexImage FromBitmap(BitmapData imageData)
{
// check image format
if (imageData.PixelFormat != PixelFormat.Format8bppIndexed)
{
throw new UnsupportedImageFormatException("Source image can be graysclae (8bpp indexed) image only.");
}
// get source image size
int width = imageData.Width;
int height = imageData.Height;
int offset = imageData.Stride - width;
// check image size
if ((!Accord.Math.Tools.IsPowerOf2(width)) || (!Accord.Math.Tools.IsPowerOf2(height)))
{
throw new InvalidImagePropertiesException("Image width and height should be power of 2.");
}
// create new complex image
ComplexImage complexImage = new ComplexImage(width, height);
Complex[,] data = complexImage.data;
// do the job
unsafe
{
byte* src = (byte*)imageData.Scan0.ToPointer();
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, src++)
data[y, x] = new Complex((float)*src / 255, data[y, x].Imaginary);
src += offset;
}
}
return complexImage;
}
/// <summary>
/// Clone the complex image.
/// </summary>
///
/// <returns>Returns copy of the complex image.</returns>
///
public object Clone()
{
// create new complex image
ComplexImage dstImage = new ComplexImage(width, height);
Complex[,] data = dstImage.data;
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
data[i, j] = this.data[i, j];
}
}
// clone mode as well
dstImage.fourierTransformed = fourierTransformed;
return dstImage;
}