private byte[] CompressImageData(string ssid, Bitmap bmp, out bool isBackground)
{
byte[] bsData;
isBackground = true;
try
{
int width = bmp.Width;
int height = bmp.Height;
bool indexed = (bmp.PixelFormat == PixelFormat.Format8bppIndexed);
byte[] data = ImageCompressEngine.ExtractImageData(bmp);
if (_background != null)
{
if (width == _background.Width && height == _background.Height || indexed != _background.IsIndexed)
{
Debug.Assert(_background.Data.Length == data.Length);
float diff = ImageCompressEngine.XorImageData(_background.Data, 0, data, 0, _background.Data.Length);
if (diff < _ratio)
{
bsData = Compress.Deflate(data, true);
isBackground = false;
}
else
{
data = ImageCompressEngine.ExtractImageData(bmp);
UpdateBackground(ssid, width, height, indexed, data);
bsData = Compress.Deflate(data, true);
}
}
else
{
UpdateBackground(ssid, width, height, indexed, data);
bsData = Compress.Deflate(data, true);
}
}
else
{
UpdateBackground(ssid, width, height, indexed, data);
bsData = Compress.Deflate(data, true);
}
}
catch (Exception ex)
{
bsData = null;
TraceLogger.Instance.WriteException(ex);
throw;
}
return(bsData);
}
