public BasicImage(byte[] data, BitMapFileHeader fileHeader, BitMapInfoHeader infoHeader)
{
Util.CheckSizes(fileHeader, infoHeader, data.Length);
width = infoHeader.BiWidth;
actualWidth = ((infoHeader.BiBitCount * width + 31) / 32) * 4;
height = infoHeader.BiHeight;
offset = fileHeader.BfOffBits;
bytesPerPixel = infoHeader.BiBitCount / 8;
this.data = data;
}
internal static void CheckSizes(BitMapFileHeader fileHeader, BitMapInfoHeader infoHeader, int actualSize)
{
if (infoHeader.BiBitCount != 24 && infoHeader.BiBitCount != 32)
{
throw new ArgumentException("Error: nuber of bits per pixel other than 24 and 32 are not supported.");
}
if (fileHeader.BfSize != actualSize ||
infoHeader.BiWidth * infoHeader.BiHeight * (infoHeader.BiBitCount / 8) > fileHeader.BfSize)
{
throw new ArgumentException("Error: file contents don't match declared size.");
}
}
internal static void HandleBitMapFileHeader(byte[] bytes, out BitMapFileHeader header)
{
header = new BitMapFileHeader();
if (bytes[0] == 0x42 && bytes[1] == 0x4D)
{
header.BfSize = (uint)((bytes[5] << 24) + (bytes[4] << 16) + (bytes[3] << 8) + bytes[2]);
header.BfOffBits = (uint)((bytes[13] << 24) + (bytes[12] << 16) + (bytes[11] << 8) + bytes[10]);
}
else if (bytes[0] == 0x4D && bytes[1] == 0x42)
{
throw new ArgumentException("Big-endian images are not supported.");
}
else
{
throw new ArgumentException("Source is not a valid bmp file.");
}
}
internal static void ApplyGreyen(
byte[] source,
byte[] destination,
BitMapFileHeader fileHeader,
BitMapInfoHeader infoHeader)
{
var sourceImage = new BasicImage(source, fileHeader, infoHeader);
var destinationImage = new BasicImage(destination, fileHeader, infoHeader);
for (int i = 0; i < infoHeader.BiHeight; i++)
{
for (int j = 0; j < infoHeader.BiWidth; j++)
{
byte average = ToByte(sourceImage[i, j, ColourPart.Red] * RedLuminance
+ sourceImage[i, j, ColourPart.Green] * GreenLuminance
+ sourceImage[i, j, ColourPart.Blue] * BlueLuminance);
destinationImage[i, j, ColourPart.Red] = average;
destinationImage[i, j, ColourPart.Green] = average;
destinationImage[i, j, ColourPart.Blue] = average;
}
}
}
internal static void ApplyKernel(
byte[] source,
byte[] destination,
double[][] kernel,
BitMapFileHeader fileHeader,
BitMapInfoHeader infoHeader)
{
var sourceImage = new BasicImage(source, fileHeader, infoHeader);
var destinationImage = new BasicImage(destination, fileHeader, infoHeader);
var lastPart = ColourPart.Alpha;
if (infoHeader.BiBitCount == 24)
{
lastPart = ColourPart.Blue;
}
for (int i = 0; i < infoHeader.BiHeight; i++)
{
for (int j = 0; j < infoHeader.BiWidth; j++)
{
for (var part = ColourPart.Red; part <= lastPart; part++)
{
double value = 0;
for (int row = 0; row < 3; row++)
{
for (int column = 0; column < 3; column++)
{
value += kernel[row][column] * sourceImage[i - 1 + row, j - 1 + column, part];
}
}
destinationImage[i, j, part] = AbsToByte(value);
}
}
}
}
