public ColorMap <ushort> DecodeMap(Stream stream, Exif _exif)
{
var exif = (PanasonicExif)_exif;
stream.Seek(exif.RawOffset, SeekOrigin.Begin);
int row, col, i, j, sh = 0;
int[] pred = new int[2], nonz = new int[2];
var resultHeight = exif.ImageHeight;
var resultWidth = exif.CropRight;
var map = new ColorMap <ushort>(resultWidth, resultHeight, 12);
int value;
var bits = new PanasonicBitStream(stream);
for (row = 0; row < exif.ImageHeight; row++)
{
var line = map.GetRow(row);
for (col = 0; col < exif.ImageWidth; col++)
{
unchecked
{
i = col % 14;
if (i == 0)
{
pred[0] = pred[1] = nonz[0] = nonz[1] = 0;
}
if (i % 3 == 2)
{
sh = 4 >> (3 - bits.Read(2));
}
if (nonz[i & 1] != 0)
{
j = bits.Read(8);
if (j != 0)
{
pred[i & 1] -= 0x80 << sh;
if (pred[i & 1] < 0 || sh == 4)
{
pred[i & 1] &= ~(-1 << sh);
}
pred[i & 1] += j << sh;
}
}
else
{
nonz[i & 1] = bits.Read(8);
if (nonz[i & 1] != 0 || i > 11)
{
pred[i & 1] = nonz[i & 1] << 4 | bits.Read(4);
}
}
if (col >= resultWidth)
{
continue;
}
value = pred[col & 1];
if (value > 4098)
{
throw new Exception("Decoding error");
}
line.SetAndMoveNext((ushort)Math.Min(4095, value));
}
}
}
return(map);
}
private static RawImageFile <ushort> DecodeImagePart(Stream stream, PanasonicExif exif)
{
int row, col, i, j, sh = 0;
int[] pred = new int[2], nonz = new int[2];
var resultHeight = exif.ImageHeight;
var resultWidth = exif.CropRight;
var map = new RawBGGRMap <ushort>(resultWidth, resultHeight, 12);
var raw = map.GetPixel();
int value;
var bits = new PanasonicBitStream(stream);
for (row = 0; row < exif.ImageHeight; row++)
{
for (col = 0; col < exif.ImageWidth; col++)
{
unchecked
{
i = col % 14;
if (i == 0)
{
pred[0] = pred[1] = nonz[0] = nonz[1] = 0;
}
if (i % 3 == 2)
{
sh = 4 >> (3 - bits.Read(2));
}
if (nonz[i & 1] != 0)
{
j = bits.Read(8);
if (j != 0)
{
pred[i & 1] -= 0x80 << sh;
if (pred[i & 1] < 0 || sh == 4)
{
pred[i & 1] &= ~(-1 << sh);
}
pred[i & 1] += j << sh;
}
}
else
{
nonz[i & 1] = bits.Read(8);
if (nonz[i & 1] != 0 || i > 11)
{
pred[i & 1] = nonz[i & 1] << 4 | bits.Read(4);
}
}
if (col >= resultWidth)
{
continue;
}
value = pred[col & 1];
if (value > 4098)
{
throw new Exception("Decoding error");
}
raw.SetAndMoveNext((ushort)Math.Min(4095, value));
}
}
}
var result = new RawImageFile <ushort>(map)
{
Exif = exif,
};
return(result);
}
