/// <summary>
///
/// </summary>
public IInputRaster <T> OpenRaster <T>(string path)
where T : IPixel, new()
{
// open image file for reading
ErdasImageFile image = new ErdasImageFile(path, RWFlag.Read);
// construct an InputRaster using that
return(new ErdasInputRaster <T>(image, path));
}
private T pixel; // a pixel: used for xfering data
/// <summary>
/// Constructor - takes an already constructed ERDAS image file
/// </summary>
public ErdasInputRaster(ErdasImageFile image, string path)
: base(path)
{
this.disposed = false;
this.image = image;
this.pixel = new T();
// make sure we've got valid input
if (this.image == null)
{
throw new System.ApplicationException("InputRaster constructor passed null image");
}
// check if trying to read a WriteOnly file
if (this.image.Mode == RWFlag.Write)
{
throw new System.ApplicationException("InputRaster can't be created for WriteOnly image");
}
// pixel vs. image bandcount mismatch?
int pixelBandCount = this.pixel.BandCount;
if (pixelBandCount != image.BandCount)
{
throw new System.ApplicationException("InputRaster band count mismatch");
}
// check bandtype compatibilities
for (int i = 0; i < pixelBandCount; i++)
{
IPixelBand band = this.pixel[i];
if (image.BandType == System.TypeCode.Byte)
{
if (band.TypeCode != System.TypeCode.Byte)
{
throw new System.ApplicationException("InputRaster band type mismatch");
}
}
else if (image.BandType == System.TypeCode.UInt16)
{
if (band.TypeCode != System.TypeCode.UInt16)
{
throw new System.ApplicationException("InputRaster band type mismatch");
}
}
else
{
throw new System.ApplicationException("InputRaster - Unsupported band type");
}
// shouldn't really ever get to this exception
// ErdasImageFile construction code should have
// thrown an exception earlier
}
}
private bool disposed = false; // track whether resources have been released
/// <summary>
/// Constructor - takes an already constructed ERDAS image file
/// </summary>
public ErdasOutputRaster(ErdasImageFile image, string path, Dimensions dimensions, IMetadata metadata)
: base(path, dimensions, metadata)
{
this.image = image;
// make sure we got valid image
if (this.image == null)
{
throw new System.ApplicationException("OutputRaster constructor passed null image");
}
// make sure image is not readonly
if (this.image.Mode == RWFlag.Read)
{
throw new System.ApplicationException("OutputRaster cannot be constructed on ReadOnly image");
}
// Begin test bandtype compatibilities
T desiredLayout = new T();
int bandCount = desiredLayout.BandCount;
System.TypeCode bandType = desiredLayout[0].TypeCode;
// check band 0
if (bandType != image.BandType)
{
throw new System.ApplicationException("OutputRaster band type mismatch");
}
// check bands 1 to n-1
for (int i = 1; i < bandCount; i++)
{
IPixelBand band = desiredLayout[i];
if (band.TypeCode != bandType)
{
throw new System.ApplicationException("OutputRasters with mixed band types not supported");
}
}
}
/// <summary>
///
/// </summary>
public IOutputRaster <T> CreateRaster <T>(string path,
Dimensions dimensions,
IMetadata metadata)
where T : IPixel, new()
{
// extract necessary parameters from pixel for image creation
T desiredLayout = new T();
int bandCount = desiredLayout.BandCount;
System.TypeCode bandType = desiredLayout[0].TypeCode;
// open image file for writing
ErdasImageFile image
= new
ErdasImageFile(path, dimensions, bandCount, bandType, metadata);
// construct an OutputRaster from that
return(new ErdasOutputRaster <T>(image, path, dimensions, metadata));
}
