// private methods
/// <summary>
/// This method checks if the image is a valid JPEG and processes some parameters.
/// </summary>
private void ProcessParameters()
{
type = Element.JPEG;
originalType = ORIGINAL_JPEG;
Stream istr = null;
try {
string errorID;
if (rawData == null)
{
WebRequest w = WebRequest.Create(url);
istr = w.GetResponse().GetResponseStream();
errorID = url.ToString();
}
else
{
istr = new MemoryStream(rawData);
errorID = "Byte array";
}
if (istr.ReadByte() != 0xFF || istr.ReadByte() != 0xD8)
{
throw new BadElementException(MessageLocalization.GetComposedMessage("1.is.not.a.valid.jpeg.file", errorID));
}
bool firstPass = true;
int len;
while (true)
{
int v = istr.ReadByte();
if (v < 0)
{
throw new IOException(MessageLocalization.GetComposedMessage("premature.eof.while.reading.jpg"));
}
if (v == 0xFF)
{
int marker = istr.ReadByte();
if (firstPass && marker == M_APP0)
{
firstPass = false;
len = GetShort(istr);
if (len < 16)
{
Utilities.Skip(istr, len - 2);
continue;
}
byte[] bcomp = new byte[JFIF_ID.Length];
int r = istr.Read(bcomp, 0, bcomp.Length);
if (r != bcomp.Length)
{
throw new BadElementException(MessageLocalization.GetComposedMessage("1.corrupted.jfif.marker", errorID));
}
bool found = true;
for (int k = 0; k < bcomp.Length; ++k)
{
if (bcomp[k] != JFIF_ID[k])
{
found = false;
break;
}
}
if (!found)
{
Utilities.Skip(istr, len - 2 - bcomp.Length);
continue;
}
Utilities.Skip(istr, 2);
int units = istr.ReadByte();
int dx = GetShort(istr);
int dy = GetShort(istr);
if (units == 1)
{
dpiX = dx;
dpiY = dy;
}
else if (units == 2)
{
dpiX = (int)((float)dx * 2.54f + 0.5f);
dpiY = (int)((float)dy * 2.54f + 0.5f);
}
Utilities.Skip(istr, len - 2 - bcomp.Length - 7);
continue;
}
if (marker == M_APPE)
{
len = GetShort(istr) - 2;
byte[] byteappe = new byte[len];
for (int k = 0; k < len; ++k)
{
byteappe[k] = (byte)istr.ReadByte();
}
if (byteappe.Length >= 12)
{
string appe = System.Text.ASCIIEncoding.ASCII.GetString(byteappe, 0, 5);
if (Util.EqualsIgnoreCase(appe, "adobe"))
{
invert = true;
}
}
continue;
}
if (marker == M_APP2)
{
len = GetShort(istr) - 2;
byte[] byteapp2 = new byte[len];
for (int k = 0; k < len; ++k)
{
byteapp2[k] = (byte)istr.ReadByte();
}
if (byteapp2.Length >= 14)
{
String app2 = System.Text.ASCIIEncoding.ASCII.GetString(byteapp2, 0, 11);
if (app2.Equals("ICC_PROFILE"))
{
int order = byteapp2[12] & 0xff;
int count = byteapp2[13] & 0xff;
// some jpeg producers don't know how to count to 1
if (order < 1)
{
order = 1;
}
if (count < 1)
{
count = 1;
}
if (icc == null)
{
icc = new byte[count][];
}
icc[order - 1] = byteapp2;
}
}
continue;
}
firstPass = false;
int markertype = MarkerType(marker);
if (markertype == VALID_MARKER)
{
Utilities.Skip(istr, 2);
if (istr.ReadByte() != 0x08)
{
throw new BadElementException(MessageLocalization.GetComposedMessage("1.must.have.8.bits.per.component", errorID));
}
scaledHeight = GetShort(istr);
Top = scaledHeight;
scaledWidth = GetShort(istr);
Right = scaledWidth;
colorspace = istr.ReadByte();
bpc = 8;
break;
}
else if (markertype == UNSUPPORTED_MARKER)
{
throw new BadElementException(MessageLocalization.GetComposedMessage("1.unsupported.jpeg.marker.2", errorID, marker));
}
else if (markertype != NOPARAM_MARKER)
{
Utilities.Skip(istr, GetShort(istr) - 2);
}
}
}
}
finally {
if (istr != null)
{
istr.Close();
}
}
plainWidth = this.Width;
plainHeight = this.Height;
if (icc != null)
{
int total = 0;
for (int k = 0; k < icc.Length; ++k)
{
if (icc[k] == null)
{
icc = null;
return;
}
total += icc[k].Length - 14;
}
byte[] ficc = new byte[total];
total = 0;
for (int k = 0; k < icc.Length; ++k)
{
System.Array.Copy(icc[k], 14, ficc, total, icc[k].Length - 14);
total += icc[k].Length - 14;
}
try {
ICC_Profile icc_prof = ICC_Profile.GetInstance(ficc);
TagICC = icc_prof;
}
catch {}
icc = null;
}
}