/// <summary>
/// Reads a property item specified by the PropertyItemID value and returns it as a string value.
/// </summary>
/// <param name="nPropertyID">Specifies the PropertyItem to get and read.</param>
/// <returns></returns>
public string GetExifProperty(PropertyItemID nPropertyID)
{
// Return an empty value if the PropertyItems array is null.
if (m_oPropertyItems == null)
return string.Empty;
int nID = (int)nPropertyID;
string sData = string.Empty;
foreach (PropertyItem oPropertyItem in m_oPropertyItems)
{
if ((oPropertyItem != null) && (oPropertyItem.Id == nID))
{
switch (oPropertyItem.Type)
{
case PROP_TYPE_BYTE:
case PROP_TYPE_ASCII:
sData = FormatTypeASCIIValue(oPropertyItem, nPropertyID);
break;
case PROP_TYPE_RATIONAL:
sData = FormatTypeRationalValue(oPropertyItem, nPropertyID);
break;
case PROP_TYPE_SRATIONAL:
sData = FormatTypeSRationalValue(oPropertyItem, nPropertyID);
break;
case PROP_TYPE_SHORT:
sData = FormatTypeShortValue(oPropertyItem, nPropertyID);
break;
case PROP_TYPE_UNDEFINED:
sData = FormatTypeUndefinedValue(oPropertyItem, nPropertyID);
break;
}
break;
}
}
return sData;
}
/// <summary>
///
/// </summary>
/// <param name="oPropertyItem"></param>
/// <param name="nID"></param>
/// <returns></returns>
private string FormatTypeUndefinedValue(PropertyItem oPropertyItem, PropertyItemID nID)
{
switch (nID)
{
case PropertyItemID.ComponentsConfiguration:
return GetComponentsConfiguration(oPropertyItem);
case PropertyItemID.ExifVersion:
return ASCIIEncoding.ASCII.GetString(oPropertyItem.Value);
default:
return string.Empty;
}
}
/// <summary>
///
/// </summary>
/// <param name="oPropertyItem"></param>
/// <param name="nID"></param>
/// <returns></returns>
private string FormatTypeASCIIValue(PropertyItem oPropertyItem, PropertyItemID nID)
{
switch (nID)
{
case PropertyItemID.XPComment:
case PropertyItemID.XPSubject:
return UnicodeEncoding.Unicode.GetString(oPropertyItem.Value);
default:
return ASCIIEncoding.ASCII.GetString(oPropertyItem.Value);
}
}
/// <summary>
///
/// </summary>
/// <param name="oPropertyItem"></param>
/// <param name="nID"></param>
/// <returns></returns>
private string FormatTypeSRationalValue(PropertyItem oPropertyItem, PropertyItemID nID)
{
if (oPropertyItem.Len == 8)
{
int n = BitConverter.ToInt32(oPropertyItem.Value, 0);
int d = BitConverter.ToInt32(oPropertyItem.Value, 4);
switch (nID)
{
case PropertyItemID.ShutterSpeed:
case PropertyItemID.BrightnessValue:
return ((float)n / d).ToString("N2");
}
}
return string.Empty;
}
/// <summary>
///
/// </summary>
/// <param name="oPropertyItem"></param>
/// <param name="nID"></param>
/// <returns></returns>
private string FormatTypeRationalValue(PropertyItem oPropertyItem, PropertyItemID nID)
{
if (oPropertyItem.Len == 8)
{
uint n = BitConverter.ToUInt32(oPropertyItem.Value, 0);
uint d = BitConverter.ToUInt32(oPropertyItem.Value, 4);
switch (nID)
{
case PropertyItemID.CompressedBitsPerPixel:
case PropertyItemID.ExposureTime:
return ((float)n / d).ToString("N2");
case PropertyItemID.FNumber:
return ((float)n / d).ToString("N1");
case PropertyItemID.MaxAperture:
return (n / d).ToString();
case PropertyItemID.FocalLength:
return (n / d).ToString() + " mm";
}
}
return string.Empty;
}
/// <summary>
///
/// </summary>
/// <param name="oPropertyItem"></param>
/// <param name="nID"></param>
/// <returns></returns>
private string FormatTypeShortValue(PropertyItem oPropertyItem, PropertyItemID nID)
{
switch (nID)
{
case PropertyItemID.Compression:
return GetCompression(oPropertyItem);
case PropertyItemID.Rating:
return GetRating(oPropertyItem);
case PropertyItemID.ColorSpace:
return GetColourSpace(oPropertyItem);
case PropertyItemID.ExposureMode:
return GetExposureMode(oPropertyItem);
case PropertyItemID.ExposureProgram:
return GetExposureProgram(oPropertyItem);
case PropertyItemID.Orientation:
return GetOrientation(oPropertyItem);
case PropertyItemID.Flash:
return GetFlash(oPropertyItem);
case PropertyItemID.MeteringMode:
return GetMeteringMode(oPropertyItem);
case PropertyItemID.ResolutionUnit:
return GetResolutionUnit(oPropertyItem);
case PropertyItemID.SceneCaptureType:
return GetSceneCaptureType(oPropertyItem);
case PropertyItemID.WhiteBalance:
return GetWhiteBalance(oPropertyItem);
case PropertyItemID.YCbCrPositioning:
return GetYCbCrPositioning(oPropertyItem);
case PropertyItemID.YCbCrSubSampling:
return GetYCbCrSubSampling(oPropertyItem);
case PropertyItemID.PhotometricInterpretation:
return GetPhotometricInterpretation(oPropertyItem);
case PropertyItemID.Thresholding:
return GetThresholding(oPropertyItem);
case PropertyItemID.LightSource:
return GetLightSource(oPropertyItem);
case PropertyItemID.Contrast:
return GetContrast(oPropertyItem);
case PropertyItemID.Saturation:
return GetSaturation(oPropertyItem);
case PropertyItemID.Sharpness:
return GetSharpness(oPropertyItem);
case PropertyItemID.ISOSpeed:
return oPropertyItem.Value[0].ToString();
default:
return string.Empty;
}
}
