public Bitmap preProcess(Bitmap image)
{
//The input image will be applied with preprocessing(grayscale, threshold, and reduce noise)
image = Grayscale.CommonAlgorithms.RMY.Apply(image);
image = new Threshold(127).Apply(image);
int xStart = image.Width, yStart = image.Height, xEnd = 0, yEnd = 0;
for (int i = 0; i < image.Height; i++)
{
for (int j = 0; j < image.Width; j++)
{
if (image.GetPixel(j, i).R > 127)
{
if (xStart > j)
{
xStart = j;
}
if (yStart > i)
{
yStart = i;
}
if (xEnd < j)
{
xEnd = j;
}
if (yEnd < i)
{
yEnd = i;
}
}
}
}
image = image.Clone(new Rectangle(xStart, yStart, xEnd - xStart, yEnd - yStart), System.Drawing.Imaging.PixelFormat.Format24bppRgb);
//and will be resized it to 10x10 pixels
image = new ResizeBilinear(10, 10).Apply(image);
return(image);
// Total input neurons in neural network must be 100 neurons
}