1、设置DPI

Bitmap bitmap2 = new Bitmap((int)w, (int)h);bitmap2.SetResolution(96, 96);

2、设置Graphic（如：去锯齿等）

private Graphics GetG(Bitmap bitmap)        {            Graphics g = Graphics.FromImage(bitmap);            //设置高质量插值法            g.InterpolationMode = InterpolationMode.HighQualityBicubic;            //如何将图片覆盖到G            g.CompositingMode = CompositingMode.SourceOver;            //图片呈现质量            g.CompositingQuality = CompositingQuality.HighQuality;            //文字抗锯齿            g.TextRenderingHint = TextRenderingHint.AntiAlias;            //设置高质量,低速度呈现平滑程度            g.SmoothingMode = SmoothingMode.AntiAlias;            //设置背景颜色            g.Clear(Color.White);            return g;        }

3、保存绘制的图片

if (saveFileDialog1.ShowDialog() == DialogResult.OK)            {                this.pictureBox1.Image.Save(saveFileDialog1.FileName, System.Drawing.Imaging.ImageFormat.Png);            }