using system;
using system.collections.generic;
using system.text;
using system.io;
using system.drawing;
using system.drawing.drawing2d;
using system.drawing.imaging;
namespace wujian.common
{
public class image
{
#region 正方型裁剪并缩放
///
/// 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
///
/// 吴剑 2012-08-08
/// 原图stream对象
/// 缩略图存放地址
/// 指定的边长（正方型）
/// 质量（范围0-100）
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 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
///
/// 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
///
/// 吴剑 2012-08-08
/// 原图stream对象
/// 保存路径
/// 最大宽(单位:px)
/// 最大高(单位:px)
/// 质量（范围0-100）
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 initimage.height || initimage.width == initimage.height)
{
//如果宽大于模版
if (initimage.width > targetwidth)
{
//宽按模版，高按比例缩放
newwidth = targetwidth;
newheight = initimage.height * (targetwidth / initimage.width);
}
}
//高大于宽（竖图）
else
{
//如果高大于模版
if (initimage.height > targetheight)
{
//高按模版，宽按比例缩放
newheight = targetheight;
newwidth = initimage.width * (targetheight / initimage.height);
}
}
//生成新图
//新建一个bmp图片
system.drawing.image newimage = new system.drawing.bitmap((int)newwidth, (int)newheight);
//新建一个画板
system.drawing.graphics newg = system.drawing.graphics.fromimage(newimage);
//设置质量
newg.interpolationmode = system.drawing.drawing2d.interpolationmode.highqualitybicubic;
newg.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality;
//置背景色
newg.clear(color.white);
//画图
newg.drawimage(initimage, new system.drawing.rectangle(0, 0, newimage.width, newimage.height), new system.drawing.rectangle(0, 0, initimage.width, initimage.height), system.drawing.graphicsunit.pixel);
//文字水印
if (watermarktext != )
{
using (system.drawing.graphics gwater = system.drawing.graphics.fromimage(newimage))
{
system.drawing.font fontwater = new font(宋体, 10);
system.drawing.brush brushwater = new solidbrush(color.white);
gwater.drawstring(watermarktext, fontwater, brushwater, 10, 10);
gwater.dispose();
}
}
//透明图片水印
if (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 (newimage.width >= wrimage.width && newimage.height >= wrimage.height)
{
graphics gwater = graphics.fromimage(newimage);
//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(newimage.width - wrimage.width, newimage.height - wrimage.height, wrimage.width, wrimage.height), 0, 0, wrimage.width, wrimage.height, graphicsunit.pixel, imgattributes);
gwater.dispose();
}
wrimage.dispose();
}
}
}
//保存缩略图
newimage.save(savepath, system.drawing.imaging.imageformat.jpeg);
//释放资源
newg.dispose();
newimage.dispose();
initimage.dispose();
}
}
#endregion
#region 其它
///
/// 判断文件类型是否为web格式图片
/// (注：jpg,gif,bmp,png)
///
/// httppostedfile.contenttype
///
public static bool iswebimage(string contenttype)
{
if (contenttype == image/pjpeg || contenttype == image/jpeg || contenttype == image/gif || contenttype == image/bmp || contenttype == image/png)
{
return true;
}
else
{
return false;
}
}
#endregion
}//end class
}