public static void SaveImage(GrayscaleImage image, string path, Func <byte, byte> color = null)
{
using (var file = File.OpenWrite(path))
{
using (var binary = new BinaryWriter(file))
{
binary.Write(Encoding.ASCII.GetBytes("BM"));
binary.Write((uint)image.ImageData.Length + 54); // File Length
binary.Write((uint)0); // Reserverd
binary.Write((uint)(54 + 4 * 256)); // Offset to Data
//Header
binary.Write((uint)40); // Header size
binary.Write(image.Width);
binary.Write(-image.Height); // "-" for topdown bitmap
binary.Write((ushort)1); // Planes (fix)
binary.Write((ushort)8); // BBP (1, 4, 8, 16, 24, 32).
binary.Write((uint)0); // Compression (0 = uncompressed)
binary.Write((uint)image.ImageData.Length); // Image Data Length
binary.Write((int)0); // XPelsPerMeter
binary.Write((int)0); // YPelsPerMeter
binary.Write((uint)0); // Count of the color palette
binary.Write((uint)0); // Count of colors
// color palette
for (var i = 0; i < 256; i++)
{
binary.Write((byte)i);
binary.Write((byte)i);
binary.Write((byte)i);
binary.Write((byte)0);
}
//Data
if (color == null)
{
for (int row = 0; row < image.Height; row++)
{
for (int column = 0; column < image.Width; column++)
{
binary.Write(image.ImageData[column, row]);
}
}
}
else
{
for (int row = 0; row < image.Height; row++)
{
for (int column = 0; column < image.Width; column++)
{
binary.Write(color(image.ImageData[column, row]));
}
}
}
}
}
}
public static IEnumerable <GrayscaleImage> LoadFromFile(string imageFile, string labelFile)
{
var result = new List <GrayscaleImage>();
List <byte> labels = new List <byte>();
using (var file = File.OpenRead(labelFile))
{
using (var binary = new BinaryReader(file))
{
var magicNumber = binary.ReadInt32().InverseEndian();
var labelCount = binary.ReadUInt32().InverseEndian();
for (var i = 0; i < labelCount; i++)
{
var label = binary.ReadByte();
labels.Add(label);
}
}
}
using (var file = File.OpenRead(imageFile))
{
using (var binary = new BinaryReader(file))
{
var magicNumber = binary.ReadInt32().InverseEndian();
var imageCount = binary.ReadInt32().InverseEndian();
var rowCount = binary.ReadInt32().InverseEndian();
var columnCount = binary.ReadInt32().InverseEndian();
for (var i = 0; i < imageCount; i++)
{
var image = new GrayscaleImage();
image.ImageLabel = labels[i];
image.ImageData = new byte[columnCount, rowCount];
image.Width = columnCount;
image.Height = rowCount;
for (var row = 0; row < rowCount; row++)
{
for (var column = 0; column < columnCount; column++)
{
image.ImageData[column, row] = binary.ReadByte();
}
}
result.Add(image);
}
}
}
return(result);
}
