public static Image Resize(Image source, ResizeTypes resizeType, int width, int height)
{
ResizeModel model = new ResizeModel();
model.Source = source;
model.ResizeType = resizeType;
model.Width = width;
model.Height = height;
return(Resize(model));
}
public static Image Resize(ResizeModel model)
{
int srcWidth, srcHeight, destWidth, destHeight, cutWidth, cutHeight, x, y;
#region 初始化变量
x = model.StartX;
y = model.StartY;
cutWidth = srcWidth = model.Source.Width;
cutHeight = srcHeight = model.Source.Height;
destWidth = model.Width;
destHeight = model.Height;
#endregion
#region 确定画布大小及裁剪尺寸
switch (model.ResizeType)
{
case ResizeTypes.Auto:
GetFinalSize(model.Width, model.Height, srcWidth, srcHeight, out destWidth, out destHeight);
break;
case ResizeTypes.Cut:
#region 裁剪算法
double srcProportion = (double)srcWidth / srcHeight;
double destProportion = (double)model.Width / model.Height;
bool autoCut = x == -1 && y == -1;
if (srcProportion >= destProportion)
{
//高瘦，固定高度，求宽度
cutWidth = (int)Math.Floor(srcHeight * destProportion);
if (autoCut)
{
x += (srcWidth - cutWidth) / 2;
}
}
else
{
//矮胖，固定宽度，球高度
cutHeight = (int)Math.Floor(srcWidth / destProportion);
if (autoCut)
{
y += (srcHeight - cutHeight) / 2;
}
}
if (x + cutWidth > srcWidth)
{
cutWidth = srcWidth - x;
}
if (y + cutHeight > srcHeight)
{
cutHeight = srcHeight - y;
}
#endregion
break;
case ResizeTypes.FixedHeight:
GetFinalSize(model.Width, model.Height, srcHeight - 1, srcHeight, out destWidth, out destHeight);
break;
case ResizeTypes.FixedWidth:
GetFinalSize(model.Width, model.Height, srcWidth, srcWidth - 1, out destWidth, out destHeight);
break;
default:
break;
}
#endregion
Image imgResult = new Bitmap(destWidth, destHeight);//结果对象
using (var g = Graphics.FromImage(imgResult))
{
//g.Clear(Color.White);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.SmoothingMode = SmoothingMode.HighQuality;
//g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
//Rectangle destRect = new Rectangle(0, 0, destWidth, destHeight);
//Rectangle srcRect = new Rectangle(x, y, cutWidth, cutHeight);
g.FillRectangle(Brushes.White, 0, 0, destWidth, destHeight);
g.DrawImage(model.Source, 0, 0, destWidth, destHeight);
//g.DrawImage(model.Source, destRect, srcRect, GraphicsUnit.Pixel);
if (model.IsWartermarked)//是否加水印
{
Image warterMark = model.ImageWartermark;
bool doImageWartermark = (null != warterMark &&
warterMark.Width < destWidth / 1 &&
warterMark.Height < destHeight / 1);//能否图片水印
if (doImageWartermark)
{
#region 图片水印
GetWatermarkPlacement(model.Position, g.DpiX, g.DpiY, destWidth, destHeight, warterMark, out x, out y);
/*
* ImageAttributes ia = new ImageAttributes();
* ColorMatrix cm = new ColorMatrix();
* cm.Matrix33 = 0.75f;
* ia.SetColorMatrix(cm);
*/
ImageAttributes ia = new ImageAttributes();
//The first step in manipulating the watermark image is to replace
//the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
//to do this we will use a Colormap and use this to define a RemapTable
ColorMap colorMap = new ColorMap();
//My watermark was defined with a background of 100% Green this will
//be the color we search for and replace with transparency
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = { colorMap };
ia.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
//The second color manipulation is used to change the opacity of the
//watermark. This is done by applying a 5x5 matrix that contains the
//coordinates for the RGBA space. By setting the 3rd row and 3rd column
//to 0.3f we achive a level of opacity
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, 0.3f, 0.0f },
new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f }
};
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
ia.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
ColorAdjustType.Bitmap);
g.DrawImage(warterMark, new Rectangle(x, y, warterMark.Width, warterMark.Height), 0, 0, warterMark.Width, warterMark.Height, GraphicsUnit.Pixel, ia);
warterMark.Dispose();
#endregion
}
else
{
#region 文字水印
int[] sizes = new int[] { 18, 16, 14, 12, 10, 8, 6, 4 };
Font font = null;
SizeF size = new SizeF();
for (int i = 0; i < 8; i++)//自动适应大小
{
font = new Font("arial", sizes[i], FontStyle.Bold);
size = g.MeasureString(model.TextWatermark, font);
if ((ushort)size.Width < (ushort)destWidth * .90)
{
break;
}
}
float fx = destWidth * .95f - size.Width;
float fy = destHeight * .99f - size.Height;
StringFormat StrFormat = new StringFormat();
StrFormat.Alignment = StringAlignment.Near;
//黑色阴影 (Alpha 153)
SolidBrush brush1 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
g.DrawString(model.TextWatermark,
font,
brush1,
new PointF(fx + 1, fy + 1),
StrFormat);
//白色前景 (Alpha 153)
SolidBrush brush2 = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
g.DrawString(model.TextWatermark,
font,
brush2,
new PointF(fx, fy),
StrFormat);
#endregion
}
}
g.Flush();
}
model.Source.Dispose();
return(imgResult);
}
