public override byte[] Decode(Bytes.Buffer data, PdfDirectObject parameters, IDictionary <PdfName, PdfDirectObject> header)
{
var imageParams = header;
var dictHeight = ((IPdfNumber)(header[PdfName.Height] ?? header[PdfName.H])).IntValue;
var dictWidth = ((IPdfNumber)(header[PdfName.Width] ?? header[PdfName.W])).IntValue;
var bitsPerComponent = ((IPdfNumber)imageParams[PdfName.BitsPerComponent])?.IntValue ?? 8;
var flag = imageParams[PdfName.ImageMask] as PdfBoolean;
var jpegOptions = new JpegOptions(decodeTransform: null, colorTransform: null);
// Checking if values need to be transformed before conversion.
var decodeObj = imageParams[PdfName.Decode] ?? imageParams[PdfName.D];
var decodeArr = decodeObj?.Resolve() as PdfArray;
if (false && decodeArr != null)
{
var decode = decodeArr.Select(p => ((IPdfNumber)p).IntValue).ToArray();
var decodeArrLength = decodeArr.Count;
var transform = new int[decodeArr.Count];
var transformNeeded = false;
var maxValue = (1 << bitsPerComponent) - 1;
for (var i = 0; i < decodeArrLength; i += 2)
{
transform[i] = ((decode[i + 1] - decode[i]) * 256) | 0;
transform[i + 1] = (decode[i] * maxValue) | 0;
if (transform[i] != 256 || transform[i + 1] != 0)
{
transformNeeded = true;
}
}
if (transformNeeded)
{
jpegOptions.DecodeTransform = transform;
}
}
// Fetching the 'ColorTransform' entry, if it exists.
if (parameters is PdfDictionary paramDict)
{
var colorTransform = paramDict[PdfName.ColorTransform];
if (colorTransform is IPdfNumber number)
{
jpegOptions.ColorTransform = number.IntValue;
}
}
var jpegImage = new JpegImage(jpegOptions);
jpegImage.Parse(data.GetBuffer());
var buffer = jpegImage.GetData(width: dictWidth, height: dictHeight, forceRGB: false, isSourcePDF: true);
return(buffer);
}