图片处理

这是一个关于图片处理的工具类:

public static class ImageHelp
{
/// <summary>
/// 获得图片的类型
/// </summary>
/// <param name="_Photo"></param>
/// <returns></returns>
public static System.Drawing.Imaging.ImageFormat ImgFormat(string _Photo)
{
//获得图片的后缀,不带点，小写
string imgExt = _Photo.Substring(_Photo.LastIndexOf(".") + 1, _Photo.Length - _Photo.LastIndexOf(".") - 1).ToLower();
System.Drawing.Imaging.ImageFormat _ImgFormat = System.Drawing.Imaging.ImageFormat.Jpeg;
switch (imgExt)
{
case "png":
_ImgFormat = System.Drawing.Imaging.ImageFormat.Png;
break;
case "gif":
_ImgFormat = System.Drawing.Imaging.ImageFormat.Gif;
break;
case "bmp":
_ImgFormat = System.Drawing.Imaging.ImageFormat.Bmp;
break;
default:
_ImgFormat = System.Drawing.Imaging.ImageFormat.Jpeg;
break;
}
return _ImgFormat;
}
#region 生成缩略图
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">生成缩略图的方式
/// <code>HW:指定高宽缩放（可能变形）</code>
/// <code>W:指定宽，高按比例 </code>
/// <code>H:指定高，宽按比例</code>
/// <code>CUT:指定高宽裁减（不变形） </code>
/// <code>FILL:填充</code>
/// </param>
public static bool LocalImage2Thumbs(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
Image2Thumbs(originalImage, thumbnailPath, width, height, mode);
originalImage.Dispose();
return true;
}
/// <summary>
/// 生成远程图片的缩略图
/// </summary>
/// <param name="remoteImageUrl"></param>
/// <param name="thumbnailPath"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="mode"></param>
/// <returns></returns>
public static bool RemoteImage2Thumbs(string remoteImageUrl, string thumbnailPath, int width, int height, string mode)
{
try
{
WebRequest request = WebRequest.Create(remoteImageUrl);
request.Timeout = 20000;
Stream stream = request.GetResponse().GetResponseStream();
System.Drawing.Image originalImage = System.Drawing.Image.FromStream(stream);
Image2Thumbs(originalImage, thumbnailPath, width, height, mode);
originalImage.Dispose();
return true;
}
catch
{
return false;
}
}

/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="originalImage">源图</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="photoWidth">最终缩略图宽度</param>
/// <param name="height">最终缩略图高度</param>
/// <param name="mode">生成缩略图的方式
/// <code>HW:指定高宽缩放（可能变形）</code>
/// <code>W:指定宽，高按比例 </code>
/// <code>H:指定高，宽按比例</code>
/// <code>CUT:指定高宽裁减（不变形） </code>
/// <code>FILL:填充</code>
/// </param>
public static void Image2Thumbs(System.Drawing.Image originalImage, string thumbnailPath, int photoWidth, int photoHeight, string mode)
{
#region 开始画图
int lastPhotoWidth = photoWidth;//最后缩略图的宽度
int lastPhotoHeight = photoHeight;//最后缩略图的高度

int toWidth = photoWidth;//原图片被压缩的宽度
int toHeight = photoHeight;//原图片被压缩的高度

int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;

int bg_x = 0;
int bg_y = 0;
switch (mode.ToUpper())
{
case "FILL"://压缩填充至指定区域
toHeight = photoHeight;
toWidth = toHeight * ow / oh;
if (toWidth > photoWidth)
{
toHeight = toHeight * photoWidth / toWidth;
toWidth = photoWidth;
}
bg_x = (photoWidth - toWidth) / 2;
bg_y = (photoHeight - toHeight) / 2;
break;
case "HW"://指定高宽缩放（可能变形）
break;
case "W"://指定宽，高按比例
toHeight = lastPhotoHeight = originalImage.Height * photoWidth / originalImage.Width;
break;
case "H"://指定高，宽按比例
toWidth = lastPhotoWidth = originalImage.Width * photoHeight / originalImage.Height;
break;
case "CUT"://指定高宽裁减（不变形）
if ((double)originalImage.Width / (double)originalImage.Height > (double)lastPhotoWidth / (double)lastPhotoHeight)
{
oh = originalImage.Height;
ow = originalImage.Height * lastPhotoWidth / lastPhotoHeight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * photoHeight / lastPhotoWidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}
System.Drawing.Image bitmap = new System.Drawing.Bitmap(lastPhotoWidth, lastPhotoHeight,PixelFormat.Format24bppRgb);//新建一个bmp图片
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);//新建一个画板
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;//设置高质量插值法
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度
g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.Clear(System.Drawing.Color.White);//白色
g.DrawImage(originalImage, new System.Drawing.Rectangle(bg_x, bg_y, toWidth, toHeight),//在指定位置并且按指定大小绘制原图片的指定部分
new System.Drawing.Rectangle(x, y, ow, oh),
System.Drawing.GraphicsUnit.Pixel);
try
{
bitmap.Save(thumbnailPath, ImgFormat(thumbnailPath));
}
catch (System.Exception e)
{
throw e;
}
finally
{

bitmap.Dispose();
g.Dispose();
}
#endregion
}
#endregion
/// <summary>
/// 切割后生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="toW">缩略图最终宽度</param>
/// <param name="toH">缩略图最终高度</param>
/// <param name="X">X坐标（zoom为1时）</param>
/// <param name="Y">Y坐标（zoom为1时）</param>
/// <param name="W">选择区域宽（zoom为1时）</param>
/// <param name="H">选择区域高（zoom为1时）</param>
public static void MakeMyThumbs(string originalImagePath, string thumbnailPath, int toW, int toH, int X, int Y, int W, int H)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
int towidth = toW;
int toheight = toH;
int x = X;
int y = Y;
int ow = W;
int oh = H; //新建一个bmp图片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;//设置高质量插值法
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度
g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//清空画布并以透明背景色填充
g.Clear(System.Drawing.Color.Transparent);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight),
new System.Drawing.Rectangle(x, y, ow, oh),
System.Drawing.GraphicsUnit.Pixel);
try
{
bitmap.Save(thumbnailPath, ImgFormat(thumbnailPath));

}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}
#region 在图片上增加文字水印
/// <summary>
/// 在图片上增加文字水印
/// </summary>
/// <param name="Path">原服务器图片路径</param>
/// <param name="Path_sy">生成的带文字水印的图片路径</param>
/// <param name="addText">水印文字</param>
public static void AddWater(string Path, string Path_sy, string addText)
{
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(image, 0, 0, image.Width, image.Height);
System.Drawing.Font f = new System.Drawing.Font("Verdana", 60);
System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Green);

g.DrawString(addText, f, b, 35, 35);
g.Dispose();

image.Save(Path_sy);
image.Dispose();
}
#endregion

#region 在图片上生成图片水印
/// <summary>
/// 加图片水印
/// </summary>
/// <param name="filename">文件名</param>
/// <param name="watermarkFilename">水印文件名</param>
/// <param name="watermarkStatus">图片水印位置:0=不使用 1=左上 2=中上 3=右上 4=左中 ... 9=右下</param>
/// <param name="quality">是否是高质量图片 取值范围0--100</param>
/// <param name="watermarkTransparency">图片水印透明度 取值范围1--10 (10为不透明)</param>

public static void AddImageSignPic(string Path, string filename, string watermarkFilename, int watermarkStatus, int quality, int watermarkTransparency)
{
System.Drawing.Image img = System.Drawing.Image.FromFile(Path);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(img);

//设置高质量插值法
//g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
//g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
System.Drawing.Image watermark = new System.Drawing.Bitmap(watermarkFilename);

if (watermark.Height >= img.Height || watermark.Width >= img.Width)
{
return;
}

System.Drawing.Imaging.ImageAttributes imageAttributes = new System.Drawing.Imaging.ImageAttributes();
System.Drawing.Imaging.ColorMap colorMap = new System.Drawing.Imaging.ColorMap();

colorMap.OldColor = System.Drawing.Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = System.Drawing.Color.FromArgb(0, 0, 0, 0);
System.Drawing.Imaging.ColorMap[] remapTable = { colorMap };

imageAttributes.SetRemapTable(remapTable, System.Drawing.Imaging.ColorAdjustType.Bitmap);

float transparency = 0.5F;
if (watermarkTransparency >= 1 && watermarkTransparency <= 10)
{
transparency = (watermarkTransparency / 10.0F);
}

float[][] colorMatrixElements = {
new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, transparency, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}
};

System.Drawing.Imaging.ColorMatrix colorMatrix = new System.Drawing.Imaging.ColorMatrix(colorMatrixElements);

imageAttributes.SetColorMatrix(colorMatrix, System.Drawing.Imaging.ColorMatrixFlag.Default, System.Drawing.Imaging.ColorAdjustType.Bitmap);

int xpos = 0;
int ypos = 0;

switch (watermarkStatus)
{
case 1:
xpos = (int)(img.Width * (float).01);
ypos = (int)(img.Height * (float).01);
break;
case 2:
xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));
ypos = (int)(img.Height * (float).01);
break;
case 3:
xpos = (int)((img.Width * (float).99) - (watermark.Width));
ypos = (int)(img.Height * (float).01);
break;
case 4:
xpos = (int)(img.Width * (float).01);
ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));
break;
case 5:
xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));
ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));
break;
case 6:
xpos = (int)((img.Width * (float).99) - (watermark.Width));
ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));
break;
case 7:
xpos = (int)(img.Width * (float).01);
ypos = (int)((img.Height * (float).99) - watermark.Height);
break;
case 8:
xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));
ypos = (int)((img.Height * (float).99) - watermark.Height);
break;
case 9:
xpos = (int)((img.Width * (float).99) - (watermark.Width));
ypos = (int)((img.Height * (float).99) - watermark.Height);
break;
}

g.DrawImage(watermark, new System.Drawing.Rectangle(xpos, ypos, watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, System.Drawing.GraphicsUnit.Pixel, imageAttributes);

System.Drawing.Imaging.ImageCodecInfo[] codecs = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders();
System.Drawing.Imaging.ImageCodecInfo ici = null;
foreach (System.Drawing.Imaging.ImageCodecInfo codec in codecs)
{
//if (codec.MimeType.IndexOf("jpeg") > -1)
if (codec.MimeType.Contains("jpeg"))
{
ici = codec;
}
}
System.Drawing.Imaging.EncoderParameters encoderParams = new System.Drawing.Imaging.EncoderParameters();
long[] qualityParam = new long[1];
if (quality < 0 || quality > 100)
{
quality = 80;
}
qualityParam[0] = quality;

System.Drawing.Imaging.EncoderParameter encoderParam = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);
encoderParams.Param[0] = encoderParam;

if (ici != null)
{
img.Save(filename, ici, encoderParams);
}
else
{
img.Save(filename);
}

g.Dispose();
img.Dispose();
watermark.Dispose();
imageAttributes.Dispose();
}

/// <summary>
/// 在图片上生成图片水印
/// </summary>
/// <param name="Path">原服务器图片路径</param>
/// <param name="Path_syp">生成的带图片水印的图片路径</param>
/// <param name="Path_sypf">水印图片路径</param>
public static void AddWaterPic(string Path, string Path_syp, string Path_sypf)
{
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel);
g.Dispose();

image.Save(Path_syp);
image.Dispose();
}
#endregion
}