public static string GetMagicWord(PNMType ptype, PNMEncoding encoding)
{
if (ptype == PNMType.PGM && encoding == PNMEncoding.ASCIIEncoding)
{
return("P2");
}
if (ptype == PNMType.PGM && encoding == PNMEncoding.BinaryEncoding)
{
return("P5");
}
if (ptype == PNMType.PPM && encoding == PNMEncoding.ASCIIEncoding)
{
return("P3");
}
if (ptype == PNMType.PPM && encoding == PNMEncoding.BinaryEncoding)
{
return("P6");
}
if (ptype == PNMType.PBM && encoding == PNMEncoding.ASCIIEncoding)
{
return("P1");
}
if (ptype == PNMType.PBM && encoding == PNMEncoding.BinaryEncoding)
{
throw new Exception("PBM files are only written in ASCII encoding.");
}
return("P5");
}
public static void WritePNM(string FilePath, System.Drawing.Image im, PNMEncoding encoding, PNMType ptype)
{
FileStream fs = new FileStream(FilePath, FileMode.Create, FileAccess.Write, FileShare.None);
IPNMDataWriter dw = PNMFactory.GetIPNMDataWriter(fs, encoding);
if (dw == null)
{
throw new Exception
("Currently only Binary and ASCII encoding is supported");
}
try
{
//write image header
dw.WriteLine(PNMFactory.GetMagicWord(ptype, encoding));
dw.WriteLine(im.Width.ToString() + " " + im.Height.ToString());
if (ptype != PNMType.PBM)
{
dw.WriteLine("255");
}
IPNMWriter imWriter = PNMFactory.GetIPNMWriter(ptype);
imWriter.WriteImageData(dw, im);
}
catch { throw; }
}
public static IPNMDataWriter GetIPNMDataWriter
(FileStream fs, PNMEncoding encoding)
{
IPNMDataWriter dw = null;
switch (encoding)
{
case PNMEncoding.ASCIIEncoding:
dw = new ASCIIDataWriter(fs);
break;
case PNMEncoding.BinaryEncoding:
dw = new BinaryDataWriter(fs);
break;
}
return(dw);
}
public static System.Drawing.Image ReadPNM(string FilePath)
{
char fchar;
int max, width, height;
string line, ftype;
FileStream fs = new FileStream
(FilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
/* Read first line, and test if it is propoer PNM type */
line = ((char)fs.ReadByte()).ToString() + ((char)fs.ReadByte()).ToString();
ftype = line;
//read off the endline char
fs.ReadByte();
PNMEncoding encoding = PNMFactory.GetPNMEncoding(ftype);
IPNMDataReader dr = PNMFactory.GetIPNMDataReader(fs, encoding);
if (dr == null)
{
throw new Exception
("Currently only Binary and ASCII encoding is supported");
}
IPNMReader imReader = PNMFactory.GetIPNMReader(PNMFactory.GetPNMType(ftype));
if (imReader == null)
{
throw new Exception
("Currently only PBM, PGM and PNM Image Types are supported");
}
/* Read lines, ignoring those starting with Comment Character, until the
* Image Dimensions are read. */
do
{
//read first char to determine if its a comment
line = dr.ReadLine();
if (line.Length == 0)
{
fchar = '#';
}
else
{
fchar = line.Substring(0, 1).ToCharArray(0, 1)[0];
}
}while(fchar == '#');
string[] toks = line.Split(new char[] { ' ' });
//read height and width
width = int.Parse(toks[0]);
height = int.Parse(toks[1]);
if (ftype != "P1")
{
/* Read lines, ignoring those starting with Comment Character, until the
* maximum pixel value is read. */
do
{
//read first char to determine if its a comment
line = dr.ReadLine();
if (line.Length == 0)
{
fchar = '#';
}
else
{
fchar = line.Substring(0, 1).ToCharArray(0, 1)[0];
}
}while(fchar == '#');
max = int.Parse(line);
if (!(max == 255))
{
Console.WriteLine
("Warning, max value for pixels in this image is not 255");
}
}
return(imReader.ReadImageData(dr, width, height));
}
public static void WritePNM(string FilePath, System.Drawing.Image im, PNMEncoding encoding)
{
WritePNM(FilePath, im, encoding, PNMType.PGM);
}
