/// <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);
}
/// <summary>
/// Gif动画单色化
/// </summary>
/// <param name="gifFilePath">原动画路径</param>
/// <param name="outputPath">单色后动画路径</param>
public static void Monochrome(string gifFilePath, 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);
int transIndex = gifImage.LogicalScreenDescriptor.BgColorIndex;
int c1 = (255 << 24) | (158 << 16) | (128 << 8) | 128;
int c2 = (255 << 24) | (0 << 16) | (0 << 8) | 0;
int c3 = (255 << 24) | (255 << 16) | (255 << 8) | 255;
int c4 = (255 << 24) | (0 << 16) | (0 << 8) | 0;
int[] palette = new int[] { c1, c2, c3, c4 };
byte[] buffer = new byte[12] {
128, 128, 128, 0, 0, 0, 255, 255, 255, 0, 0, 0
};
gifImage.GlobalColorTable = buffer;
gifImage.LogicalScreenDescriptor.BgColorIndex = 0;
gifImage.LogicalScreenDescriptor.GlobalColorTableSize = 4;
gifImage.LogicalScreenDescriptor.GlobalColorTableFlag = true;
int index = 0;
foreach (GifFrame f in gifImage.Frames)
{
Color32[] act = PaletteHelper.GetColor32s(f.LocalColorTable);
f.LocalColorTable = buffer;
Color bgC = act[(transIndex / 3)].Color;
byte bgGray = (byte)(bgC.R * 0.3 + bgC.G * 0.59 + bgC.B * 0.11);
BitmapData bmpData = f.Image.LockBits(new Rectangle(0, 0, f.Image.Width, f.Image.Height), ImageLockMode.ReadWrite, f.Image.PixelFormat);
unsafe
{
int *p = (int *)bmpData.Scan0.ToPointer();
for (int i = 0; i < f.Image.Width * f.Image.Height; i++)
{
if (p[i] == 0)
{
p[i] = c1;
}
else
{
Color c = Color.FromArgb(p[i]);
int gray = (byte)(c.R * 0.3 + c.G * 0.59 + c.B * 0.11);
if (gray > bgGray)
{
if (bgGray > 128)
{
p[i] = c2;
}
else
{
p[i] = c3;
}
}
else if (gray < bgGray)
{
if (bgGray > 128)
{
p[i] = c3;
}
else
{
p[i] = c2;
}
}
else
{
p[i] = c1;
}
}
}
}
f.Image.UnlockBits(bmpData);
f.GraphicExtension.TranIndex = 0;
f.ColorDepth = 2;
f.ImageDescriptor.LctFlag = false;
index++;
}
GifEncoder.Encode(gifImage, outputPath);
}