制作方形图像

Question

如何将图像重新取样为方形,在c#中使用白色背景填充而不使用任何第三方库(仅限.Net框架)？

谢谢!

Answer 1

这实际上可以很容易地完成.

public static Image PadImage(Image originalImage)
{
    int largestDimension = Math.Max(originalImage.Height, originalImage.Width);
    Size squareSize = new Size(largestDimension, largestDimension);
    Bitmap squareImage = new Bitmap(squareSize.Width, squareSize.Height);
    using (Graphics graphics = Graphics.FromImage(squareImage))
    {
        graphics.FillRectangle(Brushes.White, 0, 0, squareSize.Width, squareSize.Height);
        graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

        graphics.DrawImage(originalImage, (squareSize.Width / 2) - (originalImage.Width / 2), (squareSize.Height / 2) - (originalImage.Height / 2), originalImage.Width, originalImage.Height);
    }
    return squareImage;
}