/// <summary>
/// this method is available only for jpeg images
/// </summary>
/// <param name="jpegImage"> represents the jpegImage</param>
/// <param name="quantizationTableType"></param>
/// <returns></returns>
public static Double[,] GetQuantizationTable(Bitmap jpegImage, QuantizationTableType quantizationTableType)
{
switch (quantizationTableType)
{
case QuantizationTableType.Luminance:
//if (jpegImage.PropertyIdList.Contains(ImagePropertiesConstants.PropertyTagLuminanceTable))
//{
// var luminanceProperty = jpegImage.GetPropertyItem(ImagePropertiesConstants.PropertyTagLuminanceTable);
// var value = luminanceProperty.Value;
// var ret = new DoubleMatrix(8);
// var acccessor = ZigZagAccessorFactory.Access(ret);
// for (int index = 0; index < 64; index++)
// {
// acccessor[index] = BitConverter.ToUInt16(value, index * 2);
// }
// return ret;
//}
return ImagePropertiesConstants.LuminanceQuantizationTable;
case QuantizationTableType.Chrominance:
//if (jpegImage.PropertyIdList.Contains(ImagePropertiesConstants.PropertyTagChrominanceTable))
//{
// var chrominanceProperty = jpegImage.GetPropertyItem(ImagePropertiesConstants.PropertyTagChrominanceTable);
// var value = chrominanceProperty.Value;
// var ret = new DoubleMatrix(8);
// var acccessor = ZigZagAccessorFactory.Access(ret);
// for (int index = 0; index < 64; index++)
// {
// acccessor[index] = BitConverter.ToUInt16(value, index * 2);
// }
// return ret;
//}
return ImagePropertiesConstants.ChrominanceQuantizationTable;
}
return null;
}
/// <summary>
/// returns the jpeg quantization tables in an short array with 64 items
/// </summary>
/// <param name="jpegImage"></param>
/// <param name="quantizationTableType"></param>
/// <returns></returns>
public static short[] GetQuantizationTableArray(Bitmap jpegImage, QuantizationTableType quantizationTableType)
{
Accessor<double> accessor;
var ret = new short[64];
var j = 0;
switch (quantizationTableType)
{
case QuantizationTableType.Luminance:
//if (jpegImage.PropertyIdList.Contains(ImagePropertiesConstants.PropertyTagLuminanceTable))
//{
// var luminanceProperty = jpegImage.GetPropertyItem(ImagePropertiesConstants.PropertyTagLuminanceTable);
// var value = luminanceProperty.Value;
// for (int index = 0; index < 64; index++)
// {
// ret[index] = BitConverter.ToInt16(value, index * 2);
// }
// return ret;
//}
accessor = ZigZagAccessorFactory.Access(ImagePropertiesConstants.LuminanceQuantizationTable);
for (int index = 0; index < 64; index++)
{
ret[j] = Convert.ToInt16(accessor[index]);
}
return ret;
case QuantizationTableType.Chrominance:
//if (jpegImage.PropertyIdList.Contains(ImagePropertiesConstants.PropertyTagChrominanceTable))
//{
// var chrominanceProperty = jpegImage.GetPropertyItem(ImagePropertiesConstants.PropertyTagChrominanceTable);
// var value = chrominanceProperty.Value;
// for (int index = 0; index < 64; index++)
// {
// ret[index] = BitConverter.ToInt16(value, index * 2);
// }
// return ret;
//}
accessor = ZigZagAccessorFactory.Access(ImagePropertiesConstants.LuminanceQuantizationTable);
for (int index = 0; index < 64; index++)
{
ret[j] = Convert.ToInt16(accessor[index]);
}
return ret;
}
return null;
}