Graphics.DrawString() 生成的图片质量比原图片差很多

[foxwfb]

System.Drawing.Bitmap addBitmap = new Bitmap(StringFileName);

Graphics G = Graphics.FromImage(addBitmap);

G.DrawImage(addBitmap, 0, 0, addBitmap.Width, addBitmap.Height);


G.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

G.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

G.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;

G.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
G.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;



G.DrawString(StringSYName, richTextBox1.Font, new SolidBrush(richTextBox1.ForeColor), Left, Top);

G.Dispose();


addBitmap.Save("文件名")

源文件的大小有110多KB，很清楚的一张图片，加文字水印后，保存后的新文件，只有30K的样子，有点模糊，文件质量大不如以前，
请问有什么办法让加水印后的图片和源图片一样清晰，效果一样的不错，图片文件大小也和原来差不多！

[宝_爸]

楼主是jpg还是bmp?

[conan19771130]

up

[foxwfb]

JPG和Bmp都是一样的效果，都这如我描述的那样子。

[tommir3]

我也用过Graphics画过图片，也写上去的字，但不是水印，没出现模糊现象....
当然，我这断代码是写在时间事件里的，希望对你有所帮助

Image curImage;//存放当前图片
private Graphics curGra;//从资源文件中画出图片的画图

curImage = new Bitmap(this.screenWidth, this.screenHeight);
curGra = Graphics.FromImage(curImage);
curGra.DrawImage(GetImage("_" + i.ToString()), 0, 0, this.screenWidth, this.screenHeight);
this.CreateGraphics().DrawImage(curImage, new Point(0, 0));
this.CreateGraphics().Dispose();

this.CreateGraphics().DrawString("这是我的图片!", new Font("宋体", 50, FontStyle.Bold), Brushes.Blue, 10, 10);

[zgke]

把下面的都删除了 看看
G.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

G.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

G.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;

G.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
G.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

[foxwfb]

之前没加楼上这些，更加模糊......

[CraxyMouse]

保存的时候要设计图片质量的

Bitmap bitmap = new Bitmap(width, height);
//修改图片保存质量
ImageCodecInfo myImageCodecInfo = GetEncoderInfo("image/jpeg");
myEncoder = Encoder.Quality;
myEncoderParameters = new EncoderParameters(1);
//图片质量等级
myEncoderParameter = new EncoderParameter(myEncoder, 100L);
myEncoderParameters.Param[0] = myEncoderParameter;
//建立做图纸
Graphics g = Graphics.FromImage(bitmap);
g.Clear(Color.White);
//做图质量
g.SmoothingMode = SmoothingMode.AntiAlias;

//图像输出
bitmap.Save(Response.OutputStream, myImageCodecInfo, myEncoderParameters);

[CraxyMouse]

之前定义的三个变量
忘了不好意思
private Encoder myEncoder;
private EncoderParameter myEncoderParameter;
private EncoderParameters myEncoderParameters;

[xiaochao1987]

同样问题 绑定！

[foxwfb]

多谢7楼

[弦率]

说的好，我试试， 学习了