public static IPNMReader GetIPNMReader(PNMType ptype)
{
IPNMReader imReader = null;
switch (ptype)
{
case PNMType.PBM:
imReader = new PBMReader();
break;
case PNMType.PGM:
imReader = new PGMReader();
break;
case PNMType.PPM:
imReader = new PPMReader();
break;
}
return(imReader);
}
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));
}
