/// <summary>
/// Compresses the image data.
/// </summary>
public void CompressImageData()
{
// Do not recompress if compressed data is already present.
if (ImageDataRaw != null)
{
return;
}
if (ImageData == null)
{
return;
}
if (ImageCompression == ImageCompression.Rle)
{
RleRowLengths = new RleRowLengths(Rect.Height);
}
var compressor = ImageDataFactory.Create(this, null);
compressor.Write(ImageData);
ImageDataRaw = compressor.ReadCompressed();
Length = 2 + ImageDataRaw.Length;
if (ImageCompression == ImageCompression.Rle)
{
var rowLengthSize = Layer.PsdFile.IsLargeDocument ? 4 : 2;
Length += rowLengthSize * Rect.Height;
}
}
//////////////////////////////////////////////////////////////////
internal void LoadPixelData(PsdBinaryReader reader)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, Channel image");
if (Length == 0)
{
ImageCompression = ImageCompression.Raw;
ImageDataRaw = new Byte[0];
return;
}
var endPosition = reader.BaseStream.Position + Length;
ImageCompression = (ImageCompression)reader.ReadInt16();
var longDataLength = Length - 2;
Util.CheckByteArrayLength(longDataLength);
var dataLength = (Int32)longDataLength;
switch (ImageCompression)
{
case ImageCompression.Raw:
ImageDataRaw = reader.ReadBytes(dataLength);
break;
case ImageCompression.Rle:
// RLE row lengths
RleRowLengths = new RleRowLengths(reader, Rect.Height,
Layer.PsdFile.IsLargeDocument);
var rleDataLength = (Int32)(endPosition - reader.BaseStream.Position);
Debug.Assert(rleDataLength == RleRowLengths.Total,
"RLE row lengths do not sum to length of channel image data.");
// The PSD specification states that rows are padded to even sizes.
// However, Photoshop doesn't actually do this. RLE rows can have
// odd lengths in the header, and there is no padding between rows.
ImageDataRaw = reader.ReadBytes(rleDataLength);
break;
case ImageCompression.Zip:
case ImageCompression.ZipPrediction:
ImageDataRaw = reader.ReadBytes(dataLength);
break;
}
Util.DebugMessage(reader.BaseStream, "Load, End, Channel image, {0}",
ID, Layer.Name);
Debug.Assert(reader.BaseStream.Position == endPosition,
"Pixel data was not fully read in.");
}