收集整理自网上的一个类，支持生成水印、缩略图、调整光暗等，具体出处不记得了。对其中部分方法做了调整和增加了GDI压缩方法 。
ImageClass：
/// <summary>
/// 图片处理
/// </summary>
public class ImageClass
{
private ImageClass()
{ }
#region 生成缩略图
#region 指定一边，得到缩略图大小
/// <summary>
/// 指定一边，得到缩略图大小
/// </summary>
/// <param name="originalSize">原大小</param>
/// <param name="destSize">目标大小</param>
/// <param name="mode">方式（W：宽； H：高）</param>
/// <param name="height">实际高</param>
/// <param name="width">实际宽</param>
/// <returns></returns>
private static Size GetThumbnailSize(Size originalSize, Size destSize, string mode)
{
int towidth = destSize.Width;
int toheight = destSize.Height;
int ow = originalSize.Width;
int oh = originalSize.Height;
switch (mode)
{
case "W": //指定宽，高按比例
toheight = Convert.ToInt32(1.0 * originalSize.Height * towidth / originalSize.Width);
break;
case "H": //指定高，宽按比例
towidth = Convert.ToInt32(1.0 * originalSize.Width * toheight / originalSize.Height);
break;
}
return new Size(towidth, toheight);
}
#endregion
#region 得到最大的宽
/// <summary>
/// 得到最大的宽
/// </summary>
/// <param name="destSize">目标大小</param>
/// <param name="height"></param>
/// <returns></returns>
private static int GetMaxWidth(Size destSize, int height)
{
return Convert.ToInt32(((destSize.Width * 1.0) / destSize.Height) * height);
}
#endregion
#region 得到最大的高
/// <summary>
/// 得到最大的高
/// </summary>
/// <param name="destSize">目标大小</param>
/// <param name="height"></param>
/// <returns></returns>
private static int GetMaxHeight(Size destSize, int width)
{
return Convert.ToInt32(((destSize.Height * 1.0) / destSize.Width) * width);
}
#endregion
#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="thumbnailSize">缩略图大小</param>
/// <param name="mode">生成缩略图的方式</param>
/// <param name="keepThumbnailSize">是否保持缩略图大小，此时建议保存为png格式，否则会有黑底</param>
/// <param name="format">图片格式</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, Size thumbnailSize, ThumbnailMode mode, bool keepThumbnailSize = false, ImageFormat format = null)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
Size destSize = new Size(thumbnailSize.Width, thumbnailSize.Height); //目标图大小
Point originalPoint = new Point(0, 0); //源图起点
Size originalSize = new Size(originalImage.Width, originalImage.Height); //源图截取的大小
#region 确定缩略图大小信息
int tempHeight = 0, tempWidth = 0;
Size size = new Size(0, 0);
switch (mode)
{
#region 缩放模式
case ThumbnailMode.AspectFill:
#region AspectFill
size = GetThumbnailSize(originalSize, destSize, "W");//定宽，高自适应
if (size.Height >= destSize.Height)
{
tempHeight = GetMaxHeight(destSize, originalSize.Width);
originalPoint = GetLocation(WatermarkPosition.LeftMiddle, originalSize, new Size(originalSize.Width, tempHeight), 0).ToPoint();
originalSize.Height = tempHeight;
}
else
{
tempWidth = GetMaxWidth(destSize, originalSize.Height);
originalPoint = GetLocation(WatermarkPosition.TopCenter, originalSize, new Size(tempWidth, originalSize.Height), 0).ToPoint();
originalSize.Width = tempWidth;
}
break;
#endregion
case ThumbnailMode.AspectFit:
#region AspectFit
size = GetThumbnailSize(originalSize, destSize, "W");//定宽，高自适应
if (size.Height <= destSize.Height)
{
destSize = size;
}
else
{
size = GetThumbnailSize(originalSize, destSize, "H");//定高，宽自适应
destSize = size;
}
break;
#endregion
case ThumbnailMode.ScaleToFill:
#region ScaleToFill
break;
#endregion
case ThumbnailMode.WidthFix:
#region WidthFix
size = GetThumbnailSize(originalSize, destSize, "W");//定宽，高自适应
if (size.Height >= destSize.Height)
{
tempHeight = GetMaxHeight(destSize, originalSize.Width);
originalPoint = GetLocation(WatermarkPosition.LeftMiddle, originalSize, new Size(originalSize.Width, tempHeight), 0).ToPoint();
originalSize.Height = tempHeight;
}
else
{
destSize = size;
}
break;
#endregion
#endregion
#region 裁剪模式
case ThumbnailMode.Bottom:
case ThumbnailMode.BottomLeft:
case ThumbnailMode.BottomRight:
case ThumbnailMode.Center:
case ThumbnailMode.Left:
case ThumbnailMode.Right:
case ThumbnailMode.Top:
case ThumbnailMode.TopLeft:
case ThumbnailMode.TopRight:
destSize.Width = Math.Min(originalSize.Width, destSize.Width);
destSize.Height = Math.Min(originalSize.Height, destSize.Height);
originalPoint = GetLocation((WatermarkPosition)mode, originalSize, destSize, 0).ToPoint();
originalSize = destSize;
break;
#endregion
}
#endregion
#region 制作缩略图
System.Drawing.Image bitmap = keepThumbnailSize ? new System.Drawing.Bitmap(thumbnailSize.Width, thumbnailSize.Height) : new System.Drawing.Bitmap(destSize.Width, destSize.Height);
//新建一个画板
Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//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;
#region 绘制透明的图像
ImageAttributes vAttr = new ImageAttributes();
vAttr.SetColorKey(Color.Transparent, Color.Transparent);
g.DrawImage(bitmap, new Rectangle(0, 0, bitmap.Width, bitmap.Height), 0, 0, bitmap.Width, bitmap.Height, GraphicsUnit.Pixel, vAttr);
#endregion
//在指定位置并且按指定大小绘制原图片的指定部分
if (keepThumbnailSize)
{
var startPoint = GetLocation(WatermarkPosition.MiddleCenter, bitmap.Size, destSize);
g.DrawImage(originalImage, new Rectangle(startPoint.ToPoint(), destSize), new Rectangle(originalPoint, originalSize), GraphicsUnit.Pixel);
}
else
{
g.DrawImage(originalImage, new Rectangle(new Point(0, 0), destSize), new Rectangle(originalPoint, originalSize), GraphicsUnit.Pixel);
}
#endregion
#region 保存图片
try
{
if(format == null)
{
var ext = Path.GetExtension(thumbnailPath).ToLower();
switch(ext)
{
case ".png": format = System.Drawing.Imaging.ImageFormat.Png; break;
case ".bmp": format = System.Drawing.Imaging.ImageFormat.Bmp; break;
case ".emf": format = System.Drawing.Imaging.ImageFormat.Emf; break;
case ".exif": format = System.Drawing.Imaging.ImageFormat.Exif; break;
case ".gif": format = System.Drawing.Imaging.ImageFormat.Gif; break;
case ".ico":
case ".icon": format = System.Drawing.Imaging.ImageFormat.Icon; break;
case ".jpeg":
case ".jpg": format = System.Drawing.Imaging.ImageFormat.Jpeg; break;
case ".tiff": format = System.Drawing.Imaging.ImageFormat.Tiff; break;
case ".wmf": format = System.Drawing.Imaging.ImageFormat.Wmf; break;
default: format = System.Drawing.Imaging.ImageFormat.Png; break;
}
}
bitmap.Save(thumbnailPath, format);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
#endregion
}
#endregion
#endregion
#region 图片水印
/// <summary>
/// 图片水印处理方法
/// </summary>
/// <param name="path">需要加载水印的图片路径（绝对路径）</param>
/// <param name="waterpath">水印图片（绝对路径）</param>
/// <param name="location">水印位置（传送正确的代码）</param>
public static string ImageWatermark(string path, string waterpath, WatermarkPosition location)
{
string kz_name = Path.GetExtension(path);
if (kz_name == ".jpg" || kz_name == ".bmp" || kz_name == ".jpeg")
{
DateTime time = DateTime.Now;
string filename = "" + time.Year.ToString() + time.Month.ToString() + time.Day.ToString() + time.Hour.ToString() + time.Minute.ToString() + time.Second.ToString() + time.Millisecond.ToString();
Image img = Bitmap.FromFile(path);
Image waterimg = Image.FromFile(waterpath);
Graphics g = Graphics.FromImage(img);
var loca = GetLocation(location, img.Size, waterimg.Size);
g.DrawImage(waterimg, new Rectangle(Convert.ToInt32(loca.X), Convert.ToInt32(loca.Y), waterimg.Width, waterimg.Height));
waterimg.Dispose();
g.Dispose();
string newpath = Path.GetDirectoryName(path) + filename + kz_name;
img.Save(newpath);
img.Dispose();
File.Copy(newpath, path, true);
if (File.Exists(newpath))
{
File.Delete(newpath);
}
}
return path;
}
#endregion
#region 文字水印
/// <summary>
/// 文字水印处理方法
/// </summary>
/// <param name="path">图片路径（绝对路径），在这个图片上操作</param>
/// <param name="size">字体大小</param>
/// <param name="letter">水印文字</param>
/// <param name="color">颜色</param>
/// <param name="location">水印位置</param>
public static string LetterWatermark(string path, string letter, Font font, Color color, WatermarkPosition position)
{
string kz_name = Path.GetExtension(path);
if (kz_name == ".jpg" || kz_name == ".bmp" || kz_name == ".jpeg")
{
DateTime time = DateTime.Now;
string filename = "" + time.Year.ToString() + time.Month.ToString() + time.Day.ToString() + time.Hour.ToString() + time.Minute.ToString() + time.Second.ToString() + time.Millisecond.ToString();
Image img = Bitmap.FromFile(path);
Graphics gs = Graphics.FromImage(img);
//文字的大小
var sizeF = gs.MeasureString(letter, font);
var loca = GetLocation(position, img.Size, sizeF.ToSize());
Brush br = new SolidBrush(color);
gs.DrawString(letter, font, br, loca.X, loca.Y);
gs.Dispose();
string newpath = Path.GetDirectoryName(path) + filename + kz_name;
img.Save(newpath);
img.Dispose();
File.Copy(newpath, path, true);
if (File.Exists(newpath))
{
File.Delete(newpath);
}
}
return path;
}
#endregion
#region 调整光暗
/// <summary>
/// 调整光暗
/// </summary>
/// <param name="mybm">原始图片</param>
/// <param name="width">原始图片的长度</param>
/// <param name="height">原始图片的高度</param>
/// <param name="val">增加或减少的光暗值</param>
public Bitmap LDPic(Bitmap mybm, int width, int height, int val)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录经过处理后的图片对象
int x, y, resultR, resultG, resultB;//x、y是循环次数，后面三个是记录红绿蓝三个值的
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
resultR = pixel.R + val;//检查红色值会不会超出[0, 255]
resultG = pixel.G + val;//检查绿色值会不会超出[0, 255]
resultB = pixel.B + val;//检查蓝色值会不会超出[0, 255]
bm.SetPixel(x, y, Color.FromArgb(resultR, resultG, resultB));//绘图
}
}
return bm;
}
#endregion
#region 反色处理
/// <summary>
/// 反色处理
/// </summary>
/// <param name="mybm">原始图片</param>
/// <param name="width">原始图片的长度</param>
/// <param name="height">原始图片的高度</param>
public Bitmap RePic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录处理后的图片的对象
int x, y, resultR, resultG, resultB;
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
resultR = 255 - pixel.R;//反红
resultG = 255 - pixel.G;//反绿
resultB = 255 - pixel.B;//反蓝
bm.SetPixel(x, y, Color.FromArgb(resultR, resultG, resultB));//绘图
}
}
return bm;
}
#endregion
#region 浮雕处理
/// <summary>
/// 浮雕处理
/// </summary>
/// <param name="oldBitmap">原始图片</param>
/// <param name="Width">原始图片的长度</param>
/// <param name="Height">原始图片的高度</param>
public Bitmap FD(Bitmap oldBitmap, int Width, int Height)
{
Bitmap newBitmap = new Bitmap(Width, Height);
Color color1, color2;
for (int x = 0; x < Width - 1; x++)
{
for (int y = 0; y < Height - 1; y++)
{
int r = 0, g = 0, b = 0;
color1 = oldBitmap.GetPixel(x, y);
color2 = oldBitmap.GetPixel(x + 1, y + 1);
r = Math.Abs(color1.R - color2.R + 128);
g = Math.Abs(color1.G - color2.G + 128);
b = Math.Abs(color1.B - color2.B + 128);
if (r > 255) r = 255;
if (r < 0) r = 0;
if (g > 255) g = 255;
if (g < 0) g = 0;
if (b > 255) b = 255;
if (b < 0) b = 0;
newBitmap.SetPixel(x, y, Color.FromArgb(r, g, b));
}
}
return newBitmap;
}
#endregion
#region 拉伸图片
/// <summary>
/// 拉伸图片
/// </summary>
/// <param name="bmp">原始图片</param>
/// <param name="newW">新的宽度</param>
/// <param name="newH">新的高度</param>
public static Bitmap ResizeImage(Bitmap bmp, int newW, int newH)
{
try
{
Bitmap bap = new Bitmap(newW, newH);
Graphics g = Graphics.FromImage(bap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(bap, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bap.Width, bap.Height), GraphicsUnit.Pixel);
g.Dispose();
return bap;
}
catch
{
return null;
}
}
#endregion
#region 滤色处理
/// <summary>
/// 滤色处理
/// </summary>
/// <param name="mybm">原始图片</param>
/// <param name="width">原始图片的长度</param>
/// <param name="height">原始图片的高度</param>
public Bitmap FilPic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录滤色效果的图片对象
int x, y;
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
bm.SetPixel(x, y, Color.FromArgb(0, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion
#region 左右翻转
/// <summary>
/// 左右翻转
/// </summary>
/// <param name="mybm">原始图片</param>
/// <param name="width">原始图片的长度</param>
/// <param name="height">原始图片的高度</param>
public Bitmap RevPicLR(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, z; //x,y是循环次数,z是用来记录像素点的x坐标的变化的
Color pixel;
for (y = height - 1; y >= 0; y--)
{
for (x = width - 1, z = 0; x >= 0; x--)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
bm.SetPixel(z++, y, Color.FromArgb(pixel.R, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion
#region 上下翻转
/// <summary>
/// 上下翻转
/// </summary>
/// <param name="mybm">原始图片</param>
/// <param name="width">原始图片的长度</param>
/// <param name="height">原始图片的高度</param>
public Bitmap RevPicUD(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, z;
Color pixel;
for (x = 0; x < width; x++)
{
for (y = height - 1, z = 0; y >= 0; y--)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
bm.SetPixel(x, z++, Color.FromArgb(pixel.R, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion
#region 压缩图片
/// <summary>
/// 压缩到指定尺寸
/// </summary>
/// <param name="oldfile">原文件</param>
/// <param name="newfile">新文件</param>
public bool Compress(string oldfile, string newfile)
{
try
{
System.Drawing.Image img = System.Drawing.Image.FromFile(oldfile);
System.Drawing.Imaging.ImageFormat thisFormat = img.RawFormat;
Size newSize = new Size(100, 125);
Bitmap outBmp = new Bitmap(newSize.Width, newSize.Height);
Graphics g = Graphics.FromImage(outBmp);
g.CompositingQuality = CompositingQuality.HighQuality;
g.SmoothingMode = SmoothingMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(img, new Rectangle(0, 0, newSize.Width, newSize.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
g.Dispose();
EncoderParameters encoderParams = new EncoderParameters();
long[] quality = new long[1];
quality[0] = 100;
EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
encoderParams.Param[0] = encoderParam;
ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo jpegICI = null;
for (int x = 0; x < arrayICI.Length; x++)
if (arrayICI[x].FormatDescription.Equals("JPEG"))
{
jpegICI = arrayICI[x]; //设置JPEG编码
break;
}
img.Dispose();
if (jpegICI != null) outBmp.Save(newfile, System.Drawing.Imaging.ImageFormat.Jpeg);
outBmp.Dispose();
return true;
}
catch
{
return false;
}
}
#endregion
#region 图片灰度化
public Color Gray(Color c)
{
int rgb = Convert.ToInt32((double)(((0.3 * c.R) + (0.59 * c.G)) + (0.11 * c.B)));
return Color.FromArgb(rgb, rgb, rgb);
}
#endregion
#region 转换为黑白图片
/// <summary>
/// 转换为黑白图片
/// </summary>
/// <param name="mybt">要进行处理的图片</param>
/// <param name="width">图片的长度</param>
/// <param name="height">图片的高度</param>
public Bitmap BWPic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, result; //x,y是循环次数，result是记录处理后的像素值
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
result = (pixel.R + pixel.G + pixel.B) / 3;//取红绿蓝三色的平均值
bm.SetPixel(x, y, Color.FromArgb(result, result, result));
}
}
return bm;
}
#endregion
#region 获取图片中的各帧
/// <summary>
/// 获取图片中的各帧
/// </summary>
/// <param name="pPath">图片路径</param>
/// <param name="pSavePath">保存路径</param>
public void GetFrames(string pPath, string pSavedPath)
{
Image gif = Image.FromFile(pPath);
FrameDimension fd = new FrameDimension(gif.FrameDimensionsList[0]);
int count = gif.GetFrameCount(fd); //获取帧数(gif图片可能包含多帧，其它格式图片一般仅一帧)
for (int i = 0; i < count; i++) //以Jpeg格式保存各帧
{
gif.SelectActiveFrame(fd, i);
gif.Save(pSavedPath + "\\frame_" + i + ".jpg", ImageFormat.Jpeg);
}
}
#endregion
#region 得到区域的位置
/// <summary>
/// 得到区域的位置
/// </summary>
/// <param name="position">位置代码</param>
/// <param name="img">图片对象</param>
/// <param name="subSize">子区域大小</param>
/// <param name="margin">与边框距离</param>
/// <returns>返回左上角位置</returns>
public static PointF GetLocation(WatermarkPosition position, Size areaSize, Size subSize, float margin = 5)
{
float x = 10;
float y = 10;
//位置：左上角为(0, 0),x向右增加,y向下增加
var xLeft = margin;//X轴左
var xCenter = (areaSize.Width - subSize.Width) / 2;//X轴中间
var xRight = areaSize.Width - margin - subSize.Width;//X轴右边
var yTop = margin;//Y轴顶部
var yMiddle = (areaSize.Height - subSize.Height) / 2;//Y轴中间
var yBottom = areaSize.Height - subSize.Height - margin;//Y轴底部
switch (position)
{
case WatermarkPosition.TopRight:
x = xRight;
y = yTop;
break;
case WatermarkPosition.RightMiddle:
x = xRight;
y = yMiddle;
break;
case WatermarkPosition.BottomRight:
x = xRight;
y = yBottom;
break;
case WatermarkPosition.BottomCenter:
x = xCenter;
y = yBottom;
break;
case WatermarkPosition.BottomLeft:
x = xLeft;
y = yBottom;
break;
case WatermarkPosition.LeftMiddle:
x = xLeft;
y = yMiddle;
break;
case WatermarkPosition.TopLeft:
x = xLeft;
y = yTop;
break;
case WatermarkPosition.TopCenter:
x = xCenter;
y = yTop;
break;
case WatermarkPosition.MiddleCenter:
x = xCenter;
y = yMiddle;
break;
case WatermarkPosition.Random:
var maxX = areaSize.Width - margin * 2 - subSize.Width;
var maxY = areaSize.Height - margin * 2 - subSize.Height;
var random = new Random();
x = margin + Convert.ToSingle(random.NextDouble() * maxX);
y = margin + Convert.ToSingle(random.NextDouble() * maxY);
break;
}
return new PointF(x, y);
}
#endregion
#region GID压缩图片
/// <summary>
/// GDI压缩图片
/// </summary>
/// <param name="bmp">传入参数Bitmap</param>
/// <returns></returns>
public static byte[] ImageGdi(Bitmap bmp)
{
Bitmap xbmp = new Bitmap(bmp);
MemoryStream ms = new MemoryStream();
xbmp.Save(ms, ImageFormat.Jpeg);
byte[] buffer;
ms.Flush();
if (ms.Length > 95000)
{
//buffer = ms.GetBuffer();
double new_width = 0;
double new_height = 0;
Image m_src_image = Image.FromStream(ms);
if (m_src_image.Width >= m_src_image.Height)
{
new_width = 1024;
new_height = new_width * m_src_image.Height / (double)m_src_image.Width;
}
else if (m_src_image.Height >= m_src_image.Width)
{
new_height = 768;
new_width = new_height * m_src_image.Width / (double)m_src_image.Height;
}
Bitmap bbmp = new Bitmap((int)new_width, (int)new_height, m_src_image.PixelFormat);
Graphics m_graphics = Graphics.FromImage(bbmp);
m_graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
m_graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
m_graphics.DrawImage(m_src_image, 0, 0, bbmp.Width, bbmp.Height);
ms = new MemoryStream();
bbmp.Save(ms, ImageFormat.Jpeg);
buffer = ms.GetBuffer();
ms.Close();
return buffer;
}
else
{
buffer = ms.GetBuffer();
ms.Close();
return buffer;
}
}
#endregion
}