gifhelper.cs

gif图像处理 包括对多帧gif动画的缩放

#region Copyright & License
/*----------------------------------------------------------------
// Copyright (C) 2008 jillzhang 版权所有。 
//  
// 文件名：GifHelper.cs
// 文件功能描述：
// 
// 创建标识：jillzhang 
// 修改标识：
// 修改描述：
//
// 修改标识：
// 修改描述：
//----------------------------------------------------------------*/

/*-------------------------New BSD License ------------------
 Copyright (c) 2008, jillzhang
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

* Neither the name of jillzhang nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */
#endregion

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Collections;

namespace Jillzhang.GifUtility
{
    public enum SizeMode
    {
        Large,
        Normal
    }
    public class GifHelper
    {
        #region 对gif动画添加水印-字体颜色确定
        /// <summary>
        /// 对gif动画添加水印
        /// </summary>
        /// <param name="gifFilePath">原gif动画的路径</param>
        /// <param name="text">水印文字</param>
        /// <param name="textForceColor">水印文字的颜色，因为gif不是真彩色图片，所以在显示的时候，该颜色可能有所误差，但基本上可以确定颜色范围</param>
        /// <param name="font">字体</param>
        /// <param name="x">水印位置横坐标</param>
        /// <param name="y">水印位置纵坐标</param>
        /// <param name="outputPath">输出路径</param>
        public static void WaterMark(string gifFilePath, SizeMode sizeMode, string text, Color textForceColor, Font font, float x, float y, string outputPath)
        {
            if (!File.Exists(gifFilePath))
            {
                throw new IOException(string.Format("文件{0}不存在!", gifFilePath));
            }
            using (Bitmap ora_Img = new Bitmap(gifFilePath))
            {
                if (ora_Img.RawFormat.Guid != ImageFormat.Gif.Guid)
                {
                    throw new IOException(string.Format("文件{0}!", gifFilePath));
                }
            }
            GifImage gifImage = GifDecoder.Decode(gifFilePath);
            if (sizeMode == SizeMode.Large)
            {
                ThinkDisposalMethod(gifImage);
            }
            Color textColor = textForceColor;
            int frameCount = 0;
            foreach (GifFrame f in gifImage.Frames)
            {
                if ((sizeMode == SizeMode.Normal && frameCount++ == 0) || sizeMode == SizeMode.Large)
                {
                    Graphics g = Graphics.FromImage(f.Image);
                    g.DrawString(text, font, new SolidBrush(textColor), new PointF(x, y));
                    g.Dispose();
                    bool hasTextColor = false;
                    Color32[] colors = PaletteHelper.GetColor32s(f.LocalColorTable);
                    foreach (Color32 c in colors)
                    {
                        if (c.ARGB == textColor.ToArgb())
                        {
                            hasTextColor = true;
                            break;
                        }
                    }
                    if (!hasTextColor)
                    {
                        if (f.Palette.Length < 256)
                        {
                            int newSize = f.Palette.Length * 2;
                            Color32[] newColors = new Color32[newSize];
                            newColors[f.Palette.Length] = new Color32(textColor.ToArgb());
                            Array.Copy(colors, newColors, colors.Length);
                            byte[] lct = new byte[newColors.Length * 3];
                            int index = 0;
                            foreach (Color32 c in newColors)
                            {
                                lct[index++] = c.Red;
                                lct[index++] = c.Green;
                                lct[index++] = c.Blue;
                            }
                            f.LocalColorTable = lct;
                            f.ImageDescriptor.LctFlag = true;
                            f.ImageDescriptor.LctSize = newSize;
                            f.ColorDepth = f.ColorDepth + 1;
                        }
                        else
                        {
                            OcTreeQuantizer q = new OcTreeQuantizer(8);
                            Color32[] cs = q.Quantizer(f.Image);
                            byte[] lct = new byte[cs.Length * 3];
                            int index = 0;
                            int colorCount = 0;
                            foreach (Color32 c in cs)
                            {
                                lct[index++] = c.Red;
                                lct[index++] = c.Green;
                                lct[index++] = c.Blue;
                                if (c.ARGB == f.BgColor.ARGB)
                                {
                                    f.GraphicExtension.TranIndex = (byte)colorCount;
                                }
                                colorCount++;
                            }
                            Quantizer(f.Image, cs);
                            f.LocalColorTable = lct;
                            f.ImageDescriptor.LctFlag = true;
                            f.ImageDescriptor.LctSize = 256;
                            f.ColorDepth = 8;
                        }
                    }
                }
            }
            GifEncoder.Encode(gifImage, outputPath);
        }
        #endregion

        #region  对gif动画添加水印-字体颜色不定,根据调色板决定
        /// <summary>
        /// 对gif动画添加水印
        /// </summary>
        /// <param name="gifFilePath">原gif动画的路径</param>
        /// <param name="text">水印文字</param>
        /// <param name="textForceColor">水印文字的颜色，因为gif不是真彩色图片，所以在显示的时候，该颜色可能有所误差，但基本上可以确定颜色范围</param>
        /// <param name="font">字体</param>
        /// <param name="x">水印位置横坐标</param>
        /// <param name="y">水印位置纵坐标</param>
        /// <param name="outputPath">输出路径</param>
        public static void SmartWaterMark(string gifFilePath, string text, Color textForceColor, Font font, float x, float y, string outputPath)
        {
            if (!File.Exists(gifFilePath))
            {
                throw new IOException(string.Format("文件{0}不存在!", gifFilePath));
            }
            using (Bitmap ora_Img = new Bitmap(gifFilePath))
            {
                if (ora_Img.RawFormat.Guid != ImageFormat.Gif.Guid)
                {
                    throw new IOException(string.Format("文件{0}!", gifFilePath));
                }
            }
            GifImage gifImage = GifDecoder.Decode(gifFilePath);
            ThinkDisposalMethod(gifImage);
            Color textColor = textForceColor;// Color.FromArgb(closestC);           
            foreach (GifFrame f in gifImage.Frames)
            {
                Graphics g = Graphics.FromImage(f.Image);
                g.DrawString(text, font, new SolidBrush(textColor), new PointF(x, y));
                g.Dispose();
            }
            GifEncoder.Encode(gifImage, outputPath);
        }
        #endregion

        #region 对gif动画添加图片水印
        /// <summary>
        /// 对gif动画添加图片水印
        /// </summary>
        /// <param name="gifFilePath">原图片路径</param>
        /// <param name="waterImg">水印图片</param>
        /// <param name="x">横坐标</param>
        /// <param name="y">纵坐标</param>
        /// <param name="outputPath">输出路径</param>
        public static void WaterMark(string gifFilePath, Bitmap waterImg, float x, float y, string outputPath)
        {
            if (!File.Exists(gifFilePath))
            {
                throw new IOException(string.Format("文件{0}不存在!", gifFilePath));
            }
            using (Bitmap ora_Img = new Bitmap(gifFilePath))
            {
                if (ora_Img.RawFormat.Guid != ImageFormat.Gif.Guid)
                {
                    throw new IOException(string.Format("文件{0}!", gifFilePath));
                }
            }
            GifImage gifImage = GifDecoder.Decode(gifFilePath);
            ThinkDisposalMethod(gifImage);
            foreach (GifFrame f in gifImage.Frames)
            {
                Graphics g = Graphics.FromImage(f.Image);
                g.DrawImage(waterImg, new PointF(x, y));
                g.Dispose();
                OcTreeQuantizer q = new OcTreeQuantizer(8);
                Color32[] cs = q.Quantizer(f.Image);
                byte[] lct = new byte[cs.Length * 3];
                int index = 0;
                int colorCount = 0;
                foreach (Color32 c in cs)
                {
                    lct[index++] = c.Red;
                    lct[index++] = c.Green;
                    lct[index++] = c.Blue;
                    if (c.ARGB == f.BgColor.ARGB)
                    {
                        f.GraphicExtension.TranIndex = (byte)colorCount;
                    }
                    colorCount++;
                }
                Quantizer(f.Image, cs);
                f.LocalColorTable = lct;
                f.ImageDescriptor.LctFlag = true;
                f.ImageDescriptor.LctSize = 256;
                f.ColorDepth = 8;
            }
            GifEncoder.Encode(gifImage, outputPath);
        }
        #endregion

        #region gif动画缩略
        /// <summary>
        /// 获取gif动画的缩略图
        /// </summary>
        /// <param name="gifFilePath">原gif图片路径</param>
        /// <param name="rate">缩放大小</param>
        /// <param name="outputPath">缩略图大小</param>
        public static void GetThumbnail(string gifFilePath, double rate, string outputPath)
        {
            if (!File.Exists(gifFilePath))
            {
                throw new IOException(string.Format("文件{0}不存在!", gifFilePath));
            }
            using (Bitmap ora_Img = new Bitmap(gifFilePath))
            {
                if (ora_Img.RawFormat.Guid != ImageFormat.Gif.Guid)
                {
                    throw new IOException(string.Format("文件{0}!", gifFilePath));
                }
            }
            GifImage gifImage = GifDecoder.Decode(gifFilePath);
            if (rate != 1.0)
            {
                gifImage.LogicalScreenDescriptor.Width = (short)(gifImage.LogicalScreenDescriptor.Width * rate);
                gifImage.LogicalScreenDescriptor.Height = (short)(gifImage.LogicalScreenDescriptor.Height * rate);
                int index = 0;
                foreach (GifFrame f in gifImage.Frames)
                {
                    f.ImageDescriptor.XOffSet = (short)(f.ImageDescriptor.XOffSet * rate);
                    f.ImageDescriptor.YOffSet = (short)(f.ImageDescriptor.YOffSet * rate);
                    f.ImageDescriptor.Width = (short)(f.ImageDescriptor.Width * rate);
                    f.ImageDescriptor.Height = (short)(f.ImageDescriptor.Height * rate);
                    if (f.ImageDescriptor.Width == 0)
                    {
                        f.ImageDescriptor.Width = 1;
                    }
                    if (f.ImageDescriptor.Height == 0)
                    {
                        f.ImageDescriptor.Height = 1;
                    }
                    Bitmap bmp = new Bitmap(f.ImageDescriptor.Width, f.ImageDescriptor.Height);
                    Graphics g = Graphics.FromImage(bmp);
                    g.DrawImage(f.Image, new Rectangle(0, 0, f.ImageDescriptor.Width, f.ImageDescriptor.Height));
                    g.Dispose();                  
                    Quantizer(bmp, f.Palette);
                    f.Image.Dispose();
                    f.Image = bmp;
                    index++;
                }
                GifEncoder.Encode(gifImage, outputPath);
            }