如何生成图像的方形缩略图？

Question

我想从原件创建尺寸为75x75平方的缩略图.缩略图在一个维度中看起来不会拉伸,因为它不会跟随宽高比.

如果使用了Flickr,您将看到它们生成方形缩略图.我需要同样的东西.

任何线索或帮助表示赞赏.

编辑:

我在.NET 4.0 C#

我正在寻找以编程方式生成大拇指.如果没有可用的DLL,则需要批处理功能.

Answer 1

这来自Codeproject:

static System.Drawing.Image FixedSize(System.Drawing.Image imgPhoto, int Width, int Height)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;

float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;

nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
{
    nPercent = nPercentH;
    destX = System.Convert.ToInt16((Width -
                  (sourceWidth * nPercent)) / 2);
}
else
{
    nPercent = nPercentW;
    destY = System.Convert.ToInt16((Height -
                  (sourceHeight * nPercent)) / 2);
}

int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);

Bitmap bmPhoto = new Bitmap(Width, Height,
                  PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                 imgPhoto.VerticalResolution);

Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

grPhoto.DrawImage(imgPhoto,
    new Rectangle(destX, destY, destWidth, destHeight),
    new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
    GraphicsUnit.Pixel);

grPhoto.Dispose();
return bmPhoto;

}