public class Imager
{
#region 正方型裁剪并缩放
/// <summary>
/// 正方型裁剪
/// 以图片中心为轴心，截取正方型，然后等比缩放
/// 用于头像处理
/// </summary>
/// <param name="fromFile">原图Stream对象</param>
/// <param name="fileSaveUrl">缩略图存放地址</param>
/// <param name="side">指定的边长（正方型）</param>
/// <param name="quality">质量（范围0-100）</param>
public static void CutForSquare(System.IO.Stream fromFile, string fileSaveUrl, int side, int quality)
{
//创建目录
string dir = Path.GetDirectoryName(fileSaveUrl);
if (!Directory.Exists(dir))
Directory.CreateDirectory(dir);
//原始图片（获取原始图片创建对象，并使用流中嵌入的颜色管理信息）
System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);
//原图宽高均小于模版，不作处理，直接保存
if (initImage.Width <= side && initImage.Height <= side) {
initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
} else {
//原始图片的宽、高
int initWidth = initImage.Width;
int initHeight = initImage.Height;
//非正方型先裁剪为正方型
if (initWidth != initHeight) {
//截图对象
System.Drawing.Image pickedImage = null;
System.Drawing.Graphics pickedG = null;
//宽大于高的横图
if (initWidth > initHeight) {
//对象实例化
pickedImage = new System.Drawing.Bitmap(initHeight, initHeight);
pickedG = System.Drawing.Graphics.FromImage(pickedImage);
//设置质量
pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//定位
Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight);
Rectangle toR = new Rectangle(0, 0, initHeight, initHeight);
//画图
pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
//重置宽
initWidth = initHeight;
}
//高大于宽的竖图
else {
//对象实例化
pickedImage = new System.Drawing.Bitmap(initWidth, initWidth);
pickedG = System.Drawing.Graphics.FromImage(pickedImage);
//设置质量
pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//定位
Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth);
Rectangle toR = new Rectangle(0, 0, initWidth, initWidth);
//画图
pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
//重置高
initHeight = initWidth;
}
//将截图对象赋给原图
initImage = (System.Drawing.Image)pickedImage.Clone();
//释放截图资源
pickedG.Dispose();
pickedImage.Dispose();
}
//缩略图对象
System.Drawing.Image resultImage = new System.Drawing.Bitmap(side, side);
System.Drawing.Graphics resultG = System.Drawing.Graphics.FromImage(resultImage);
//设置质量
resultG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
resultG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//用指定背景色清空画布
resultG.Clear(Color.White);
//绘制缩略图
resultG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, side, side), new System.Drawing.Rectangle(0, 0, initWidth, initHeight), System.Drawing.GraphicsUnit.Pixel);
//关键质量控制
//获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff
ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici = null;
foreach (ImageCodecInfo i in icis) {
if (i.MimeType == "image/jpeg" || i.MimeType == "image/bmp" || i.MimeType == "image/png" || i.MimeType == "image/gif") {
ici = i;
}
}
EncoderParameters ep = new EncoderParameters(1);
ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);
//保存缩略图
resultImage.Save(fileSaveUrl, ici, ep);
//释放关键质量控制所用资源
ep.Dispose();
//释放缩略图资源
resultG.Dispose();
resultImage.Dispose();
//释放原始图片资源
initImage.Dispose();
}
}
#endregion
#region 自定义裁剪并缩放
/// <summary>
/// 指定长宽裁剪
/// 按模版比例最大范围的裁剪图片并缩放至模版尺寸
/// </summary>
/// <param name="fromFile">原图Stream对象</param>
/// <param name="fileSaveUrl">保存路径</param>
/// <param name="maxWidth">最大宽(单位:px)</param>
/// <param name="maxHeight">最大高(单位:px)</param>
/// <param name="quality">质量（范围0-100）</param>
public static void CutForCustom(System.IO.Stream fromFile, string fileSaveUrl, int maxWidth, int maxHeight, int quality)
{
//从文件获取原始图片，并使用流中嵌入的颜色管理信息
System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);
//原图宽高均小于模版，不作处理，直接保存
if (initImage.Width <= maxWidth && initImage.Height <= maxHeight) {
initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
} else {
if (maxWidth == 0) maxWidth = initImage.Width;
if (maxHeight == 0) maxHeight = initImage.Height;
//模版的宽高比例
double templateRate = (double)maxWidth / maxHeight;
//原图片的宽高比例
double initRate = (double)initImage.Width / initImage.Height;
//原图与模版比例相等，直接缩放
if (templateRate == initRate) {
//按模版大小生成最终图片
System.Drawing.Image templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);
System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);
templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
templateG.Clear(Color.White);
templateG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
}
//原图与模版比例不等，裁剪后缩放
else {
//裁剪对象
System.Drawing.Image pickedImage = null;
System.Drawing.Graphics pickedG = null;
//定位
Rectangle fromR = new Rectangle(0, 0, 0, 0);//原图裁剪定位
Rectangle toR = new Rectangle(0, 0, 0, 0);//目标定位
//宽为标准进行裁剪
if (templateRate > initRate) {
//裁剪对象实例化
pickedImage = new System.Drawing.Bitmap(initImage.Width, (int)System.Math.Floor(initImage.Width / templateRate));
pickedG = System.Drawing.Graphics.FromImage(pickedImage);
//裁剪源定位
fromR.X = 0;
fromR.Y = (int)System.Math.Floor((initImage.Height - initImage.Width / templateRate) / 2);
fromR.Width = initImage.Width;
fromR.Height = (int)System.Math.Floor(initImage.Width / templateRate);
//裁剪目标定位
toR.X = 0;
toR.Y = 0;
toR.Width = initImage.Width;
toR.Height = (int)System.Math.Floor(initImage.Width / templateRate);
}
//高为标准进行裁剪
else {
pickedImage = new System.Drawing.Bitmap((int)System.Math.Floor(initImage.Height * templateRate), initImage.Height);
pickedG = System.Drawing.Graphics.FromImage(pickedImage);
fromR.X = (int)System.Math.Floor((initImage.Width - initImage.Height * templateRate) / 2);
fromR.Y = 0;
fromR.Width = (int)System.Math.Floor(initImage.Height * templateRate);
fromR.Height = initImage.Height;
toR.X = 0;
toR.Y = 0;
toR.Width = (int)System.Math.Floor(initImage.Height * templateRate);
toR.Height = initImage.Height;
}
//设置质量
pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//裁剪
pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
//按模版大小生成最终图片
System.Drawing.Image templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);
System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);
templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
templateG.Clear(Color.White);
templateG.DrawImage(pickedImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, pickedImage.Width, pickedImage.Height), System.Drawing.GraphicsUnit.Pixel);
//关键质量控制
//获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff
ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici = null;
foreach (ImageCodecInfo i in icis) {
if (i.MimeType == "image/jpeg" || i.MimeType == "image/bmp" || i.MimeType == "image/png" || i.MimeType == "image/gif") {
ici = i;
}
}
EncoderParameters ep = new EncoderParameters(1);
ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);
//保存缩略图
templateImage.Save(fileSaveUrl, ici, ep);
//templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
//释放资源
templateG.Dispose();
templateImage.Dispose();
pickedG.Dispose();
pickedImage.Dispose();
}
}
//释放资源
initImage.Dispose();
}
#endregion
/// <summary>
/// 图片等比缩放
/// </summary>
/// <param name="filePath">原图Stream对象</param>
/// <param name="targetPath">缩略图存放地址</param>
/// <param name="targetWidth">指定的最大宽度</param>
/// <param name="targetHeight">指定的最大高度</param>
/// <param name="watermarkText">水印文字(为""表示不使用水印)</param>
/// <param name="watermarkImage">水印图片路径(为""表示不使用水印)</param>
public static void Resize(string filePath, string targetPath, double targetWidth, double targetHeight, string watermarkText = "", string watermarkImage = "")
{
//创建目录
string dir = Path.GetDirectoryName(targetPath);
if (Directory.Exists(dir) == false) Directory.CreateDirectory(dir);
//原始图片（获取原始图片创建对象，并使用流中嵌入的颜色管理信息）
Image initImage = Image.FromFile(filePath, true);
//原图宽高均小于模版或目标宽度均为0，不作处理，直接保存
if (initImage.Width <= targetWidth && initImage.Height <= targetHeight || (targetWidth == 0 && targetHeight == 0)) {
//文字水印
if (watermarkText != "") {
setWatermarkText(initImage, watermarkText);
}
//透明图片水印
if (watermarkImage != "") {
setWatermarkImage(initImage, watermarkImage);
}
//保存
initImage.Save(targetPath, ImageFormat.Jpeg);
} else {
//缩略图宽、高计算
double newWidth = 0;
double newHeight = 0;
if (targetWidth == 0) {
newWidth = initImage.Width * targetHeight / initImage.Height;
newHeight = targetHeight;
} else if(targetHeight == 0) {
newWidth = targetWidth;
newHeight = initImage.Height * targetWidth / initImage.Width;
} else {
double scaleWidth = targetWidth / initImage.Width;
double scaleHeight = targetHeight / initImage.Height;
if (scaleWidth > scaleHeight) {
newWidth = initImage.Width * scaleHeight;
newHeight = initImage.Height * scaleHeight;
} else {
newWidth = initImage.Width * scaleWidth;
newHeight = initImage.Height * scaleWidth;
}
}
//生成新图
//新建一个bmp图片
Image newImage = new Bitmap((int)newWidth, (int)newHeight);
//新建一个画板
Graphics newG = Graphics.FromImage(newImage);
//设置质量
newG.InterpolationMode = InterpolationMode.HighQualityBicubic;
newG.SmoothingMode = SmoothingMode.HighQuality;
//置背景色
newG.Clear(Color.White);
//画图
newG.DrawImage(initImage, new Rectangle(0, 0, newImage.Width, newImage.Height), new Rectangle(0, 0, initImage.Width, initImage.Height), GraphicsUnit.Pixel);
//文字水印
if (watermarkText != "") {
setWatermarkText(newImage, watermarkText);
}
//透明图片水印
if (watermarkImage != "") {
setWatermarkImage(newImage, watermarkImage);
}
//保存缩略图
newImage.Save(targetPath, ImageFormat.Jpeg);
//释放资源
newG.Dispose();
newImage.Dispose();
}
initImage.Dispose();
}
private static void setWatermarkText(Image initImage, string watermarkText)
{
using (System.Drawing.Graphics gWater = System.Drawing.Graphics.FromImage(initImage)) {
System.Drawing.Font fontWater = new Font("黑体", 10);
System.Drawing.Brush brushWater = new SolidBrush(Color.White);
gWater.DrawString(watermarkText, fontWater, brushWater, 10, 10);
gWater.Dispose();
}
}
private static void setWatermarkImage(Image initImage, string watermarkImage)
{
if (File.Exists(watermarkImage)) {
//获取水印图片
using (System.Drawing.Image wrImage = System.Drawing.Image.FromFile(watermarkImage)) {
//水印绘制条件：原始图片宽高均大于或等于水印图片
if (initImage.Width >= wrImage.Width && initImage.Height >= wrImage.Height) {
Graphics gWater = Graphics.FromImage(initImage);
//透明属性
ImageAttributes imgAttributes = new ImageAttributes();
ColorMap colorMap = new ColorMap();
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = { colorMap };
imgAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
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, 0.5f, 0.0f},//透明度:0.5
new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}
};
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imgAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
gWater.DrawImage(wrImage, new Rectangle(initImage.Width - wrImage.Width, initImage.Height - wrImage.Height, wrImage.Width, wrImage.Height), 0, 0, wrImage.Width, wrImage.Height, GraphicsUnit.Pixel, imgAttributes);
gWater.Dispose();
}
wrImage.Dispose();
}
}
}
}
浙公网安备 33010602011771号