/// <summary>
/// Decode first frame for the specified file.
/// </summary>
///
/// <param name="fileName">File name to read image from.</param>
/// <param name="imageInfo">Information about the decoded image.</param>
///
/// <returns>Return decoded image. In the case if file format support multiple
/// frames, the method return the first frame.</returns>
///
/// <remarks><para>The method uses table of registered image decoders to find the one,
/// which should be used for the specified file. If there is not appropriate decoder
/// found, the method uses default .NET's image decoding routine (see
/// <see cref="System.Drawing.Image.FromFile( string )"/>).</para></remarks>
///
public static Bitmap DecodeFromFile(string fileName, out ImageInfo imageInfo)
{
Bitmap bitmap = null;
string fileExtension = Path.GetExtension(fileName).ToUpperInvariant();
if ((fileExtension != string.Empty) && (fileExtension.Length != 0))
{
fileExtension = fileExtension.Substring(1);
if (decoders.ContainsKey(fileExtension))
{
IImageDecoder decoder = decoders[fileExtension];
// open stream
using (FileStream stream = new FileStream(fileName, FileMode.Open))
{
// open decoder
decoder.Open(stream);
// read the first frame
bitmap = decoder.DecodeFrame(0, out imageInfo);
decoder.Close();
}
return bitmap;
}
}
// use default .NET's image decoding routine
bitmap = FromFile(fileName);
imageInfo = new ImageInfo(bitmap.Width, bitmap.Height, Image.GetPixelFormatSize(bitmap.PixelFormat), 0, 1);
return bitmap;
}
/// <summary>
/// Decode specified frame.
/// </summary>
///
/// <param name="frameIndex">Image frame to decode.</param>
/// <param name="imageInfo">Receives information about decoded frame.</param>
///
/// <returns>Returns decoded frame.</returns>
///
/// <exception cref="NullReferenceException">No image stream was opened previously.</exception>
/// <exception cref="ArgumentOutOfRangeException">Stream does not contain frame with specified index.</exception>
/// <exception cref="ArgumentException">The stream contains invalid (broken) PNM image.</exception>
///
public Bitmap DecodeFrame(int frameIndex, out ImageInfo imageInfo)
{
// check requested frame index
if (frameIndex != 0)
{
throw new ArgumentOutOfRangeException("Currently opened stream does not contain frame with specified index.");
}
// seek to the required frame
stream.Seek(dataPosition, SeekOrigin.Begin);
// read required frame
Bitmap image = ReadImageFrame(stream, this.imageInfo);
// provide also frame information
imageInfo = (PNMImageInfo)this.imageInfo.Clone();
return image;
}
/// <summary>
/// Decode specified frame.
/// </summary>
///
/// <param name="frameIndex">Image frame to decode.</param>
/// <param name="imageInfo">Receives information about decoded frame.</param>
///
/// <returns>Returns decoded frame.</returns>
///
/// <exception cref="NullReferenceException">No image stream was opened previously.</exception>
/// <exception cref="ArgumentOutOfRangeException">Stream does not contain frame with specified index.</exception>
/// <exception cref="ArgumentException">The stream contains invalid (broken) FITS image.</exception>
///
public Bitmap DecodeFrame(int frameIndex, out ImageInfo imageInfo)
{
// check requested frame index
if (frameIndex >= this.imageInfo.TotalFrames)
{
throw new ArgumentOutOfRangeException("Currently opened stream does not contain frame with specified index.");
}
// seek to the required frame
stream.Seek(dataPosition + frameIndex * this.imageInfo.Width * this.imageInfo.Height *
Math.Abs(this.imageInfo.OriginalBitsPerPixl) / 8, SeekOrigin.Begin);
// read required frame
Bitmap image = ReadImageFrame(stream, this.imageInfo);
// provide also frame information
imageInfo = (FITSImageInfo)this.imageInfo.Clone();
imageInfo.FrameIndex = frameIndex;
return image;
}
/// <summary>
/// Decode first frame for the specified file.
/// </summary>
///
/// <param name="fileName">File name to read image from.</param>
///
/// <returns>Return decoded image. In the case if file format support multiple
/// frames, the method return the first frame.</returns>
///
/// <remarks><para>The method uses table of registered image decoders to find the one,
/// which should be used for the specified file. If there is not appropriate decoder
/// found, the method uses default .NET's image decoding routine (see
/// <see cref="System.Drawing.Image.FromFile(string)"/>).</para></remarks>
///
public static Bitmap DecodeFromFile(string fileName)
{
ImageInfo imageInfo = null;
return(DecodeFromFile(fileName, out imageInfo));
}
