freeimagewrapper.cs

对gif

		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="filename">The complete name of the file to save to.
		/// The extension will be corrected if it is no valid extension for the
		/// selected format or if no extension was specified.</param>
		/// <param name="flags">Flags to enable or disable plugin-features.</param>
		/// <param name="unloadSource">When true the structure will be unloaded on success.
		/// If the function failed and returned false, the bitmap was not unloaded.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="filename"/> is null.</exception>
		public static bool SaveEx(
			ref FIBITMAP dib,
			string filename,
			FREE_IMAGE_SAVE_FLAGS flags,
			bool unloadSource)
		{
			return SaveEx(
				ref dib,
				filename,
				FREE_IMAGE_FORMAT.FIF_UNKNOWN,
				flags,
				FREE_IMAGE_COLOR_DEPTH.FICD_AUTO,
				unloadSource);
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a file.
		/// In case the loading format is <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>
		/// the format is taken off the filename.
		/// If no suitable format was found false will be returned.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="filename">The complete name of the file to save to.
		/// The extension will be corrected if it is no valid extension for the
		/// selected format or if no extension was specified.</param>
		/// <param name="format">Format of the image. If the format should be taken from the
		/// filename use <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>.</param>
		/// <param name="unloadSource">When true the structure will be unloaded on success.
		/// If the function failed and returned false, the bitmap was not unloaded.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="filename"/> is null.</exception>
		public static bool SaveEx(
			ref FIBITMAP dib,
			string filename,
			FREE_IMAGE_FORMAT format,
			bool unloadSource)
		{
			return SaveEx(
				ref dib,
				filename,
				format,
				FREE_IMAGE_SAVE_FLAGS.DEFAULT,
				FREE_IMAGE_COLOR_DEPTH.FICD_AUTO,
				unloadSource);
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a file.
		/// In case the loading format is <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>
		/// the format is taken off the filename.
		/// If no suitable format was found false will be returned.
		/// Save flags can be provided by the flags parameter.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="filename">The complete name of the file to save to.
		/// The extension will be corrected if it is no valid extension for the
		/// selected format or if no extension was specified.</param>
		/// <param name="format">Format of the image. If the format should be taken from the
		/// filename use <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>.</param>
		/// <param name="flags">Flags to enable or disable plugin-features.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="filename"/> is null.</exception>
		public static bool SaveEx(
			FIBITMAP dib,
			string filename,
			FREE_IMAGE_FORMAT format,
			FREE_IMAGE_SAVE_FLAGS flags)
		{
			return SaveEx(
				ref dib,
				filename,
				format,
				flags,
				FREE_IMAGE_COLOR_DEPTH.FICD_AUTO,
				false);
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a file.
		/// In case the loading format is <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>
		/// the format is taken off the filename.
		/// If no suitable format was found false will be returned.
		/// Save flags can be provided by the flags parameter.
		/// The bitmaps color depth can be set by 'colorDepth'.
		/// If set to <see cref="FREE_IMAGE_COLOR_DEPTH.FICD_AUTO"/> a suitable color depth
		/// will be taken if available.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="filename">The complete name of the file to save to.
		/// The extension will be corrected if it is no valid extension for the
		/// selected format or if no extension was specified.</param>
		/// <param name="format">Format of the image. If the format should be taken from the
		/// filename use <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>.</param>
		/// <param name="flags">Flags to enable or disable plugin-features.</param>
		/// <param name="colorDepth">The new color depth of the bitmap.
		/// Set to <see cref="FREE_IMAGE_COLOR_DEPTH.FICD_AUTO"/> if Save should take the
		/// best suitable color depth.
		/// If a color depth is selected that the provided format cannot write an
		/// error-message will be thrown.</param>
		/// <param name="unloadSource">When true the structure will be unloaded on success.
		/// If the function failed and returned false, the bitmap was not unloaded.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentException">
		/// A direct color conversion failed.</exception>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="filename"/> is null.</exception>
		public static bool SaveEx(
			ref FIBITMAP dib,
			string filename,
			FREE_IMAGE_FORMAT format,
			FREE_IMAGE_SAVE_FLAGS flags,
			FREE_IMAGE_COLOR_DEPTH colorDepth,
			bool unloadSource)
		{
			if (dib.IsNull)
			{
				throw new ArgumentNullException("dib");
			}
			if (filename == null)
			{
				throw new ArgumentNullException("filename");
			}
			bool result = false;
			// Gets format from filename if the format is unknown
			if (format == FREE_IMAGE_FORMAT.FIF_UNKNOWN)
			{
				format = GetFIFFromFilename(filename);
			}
			if (format != FREE_IMAGE_FORMAT.FIF_UNKNOWN)
			{
				// Checks writing support
				if (FIFSupportsWriting(format) && FIFSupportsExportType(format, GetImageType(dib)))
				{
					// Check valid filename and correct it if needed
					if (!IsFilenameValidForFIF(format, filename))
					{
						int index = filename.LastIndexOf('.');
						string extension = GetPrimaryExtensionFromFIF(format);

						if (index == -1)
						{
							// We have no '.' (dot) so just add the extension
							filename += "." + extension;
						}
						else
						{
							// Overwrite the old extension
							filename = filename.Substring(0, filename.LastIndexOf('.')) + extension;
						}
					}

					FIBITMAP dibToSave = PrepareBitmapColorDepth(dib, format, colorDepth);
					result = Save(format, dibToSave, filename, flags);

					// Always unload a temporary created bitmap.
					if (dibToSave != dib)
					{
						UnloadEx(ref dibToSave);
					}
					// On success unload the bitmap
					if (result && unloadSource)
					{
						UnloadEx(ref dib);
					}
				}
			}
			return result;
		}

		/// <summary>
		/// Loads a FreeImage bitmap.
		/// The stream must be set to the correct position before calling LoadFromStream.
		/// </summary>
		/// <param name="stream">The stream to read from.</param>
		/// <returns>Handle to a FreeImage bitmap.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> is not capable of reading.</exception>
		public static FIBITMAP LoadFromStream(
			Stream stream)
		{
			FREE_IMAGE_FORMAT format = FREE_IMAGE_FORMAT.FIF_UNKNOWN;
			return LoadFromStream(stream, FREE_IMAGE_LOAD_FLAGS.DEFAULT, ref format);
		}

		/// <summary>
		/// Loads a FreeImage bitmap.
		/// The stream must be set to the correct position before calling LoadFromStream.
		/// </summary>
		/// <param name="stream">The stream to read from.</param>
		/// <param name="flags">Flags to enable or disable plugin-features.</param>
		/// <returns>Handle to a FreeImage bitmap.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> is not capable of reading.</exception>
		public static FIBITMAP LoadFromStream(
			Stream stream,
			FREE_IMAGE_LOAD_FLAGS flags)
		{
			FREE_IMAGE_FORMAT format = FREE_IMAGE_FORMAT.FIF_UNKNOWN;
			return LoadFromStream(stream, flags, ref format);
		}

		/// <summary>
		/// Loads a FreeImage bitmap.
		/// In case the loading format is <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/> the
		/// bitmaps real format is being analysed.
		/// The stream must be set to the correct position before calling LoadFromStream.
		/// </summary>
		/// <param name="stream">The stream to read from.</param>
		/// <param name="format">Format of the image. If the format is unknown use
		/// <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>.
		/// In case a suitable format was found by LoadFromStream it will be returned in format.</param>
		/// <returns>Handle to a FreeImage bitmap.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> is not capable of reading.</exception>
		public static FIBITMAP LoadFromStream(
			Stream stream,
			ref FREE_IMAGE_FORMAT format)
		{
			return LoadFromStream(stream, FREE_IMAGE_LOAD_FLAGS.DEFAULT, ref format);
		}

		/// <summary>
		/// Loads a FreeImage bitmap.
		/// In case the loading format is <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>
		/// the bitmaps real format is being analysed.
		/// The stream must be set to the correct position before calling LoadFromStream.
		/// </summary>
		/// <param name="stream">The stream to read from.</param>
		/// <param name="flags">Flags to enable or disable plugin-features.</param>
		/// <param name="format">Format of the image. If the format is unknown use
		/// <see cref="FREE_IMAGE_FORMAT.FIF_UNKNOWN"/>.
		/// In case a suitable format was found by LoadFromStream it will be returned in format.</param>
		/// <returns>Handle to a FreeImage bitmap.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> is not capable of reading.</exception>
		public static FIBITMAP LoadFromStream(
			Stream stream,
			FREE_IMAGE_LOAD_FLAGS flags,
			ref FREE_IMAGE_FORMAT format)
		{
			if (stream == null)
			{
				throw new ArgumentNullException("stream");
			}
			if (!stream.CanRead)
			{
				throw new ArgumentException("stream is not capable of reading.");
			}
			// Wrap the source stream if it is unable to seek (which is required by FreeImage)
			stream = (stream.CanSeek) ? stream : new StreamWrapper(stream, true);
			// Save the streams position
			if (format == FREE_IMAGE_FORMAT.FIF_UNKNOWN)
			{
				long position = stream.Position;
				// Get the format of the bitmap
				format = GetFileTypeFromStream(stream);
				// Restore the streams position
				stream.Position = position;
			}
			if (!FIFSupportsReading(format))
			{
				return 0;
			}
			// Create a 'FreeImageIO' structure for calling 'LoadFromHandle'
			// using the internal structure 'FreeImageStreamIO'.
			FreeImageIO io = FreeImageStreamIO.io;
			using (fi_handle handle = new fi_handle(stream))
			{
				return LoadFromHandle(format, ref io, handle, flags);
			}
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a stream.
		/// The stream must be set to the correct position before calling SaveToStream.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="stream">The stream to write to.</param>
		/// <param name="format">Format of the image.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> cannot write.</exception>
		public static bool SaveToStream(
			FIBITMAP dib,
			Stream stream,
			FREE_IMAGE_FORMAT format)
		{
			return SaveToStream(
				ref dib,
				stream,
				format,
				FREE_IMAGE_SAVE_FLAGS.DEFAULT,
				FREE_IMAGE_COLOR_DEPTH.FICD_AUTO,
				false);
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a stream.
		/// The stream must be set to the correct position before calling SaveToStream.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="stream">The stream to write to.</param>
		/// <param name="format">Format of the image.</param>
		/// <param name="unloadSource">When true the structure will be unloaded on success.</param>
		/// <returns>Returns true on success, false on failure.</returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="dib"/> or <paramref name="stream"/> is null.</exception>
		/// <exception cref="ArgumentException">
		/// <paramref name="stream"/> cannot write.</exception>
		public static bool SaveToStream(
			ref FIBITMAP dib,
			Stream stream,
			FREE_IMAGE_FORMAT format,
			bool unloadSource)
		{
			return SaveToStream(
				ref dib,
				stream,
				format,
				FREE_IMAGE_SAVE_FLAGS.DEFAULT,
				FREE_IMAGE_COLOR_DEPTH.FICD_AUTO,
				unloadSource);
		}

		/// <summary>
		/// Saves a previously loaded FreeImage bitmap to a stream.
		/// The stream must be set to the correct position before calling SaveToStream.
		/// </summary>
		/// <param name="dib">Handle to a FreeImage bitmap.</param>
		/// <param name="stream">The stream to write to.</param>
		/// <param name="format">Format of the image.</param>