Question

我正在寻找一种方法来调整大小，并以16：9的固定比例将图像裁剪为特定大小。所以我有任何图像和任何尺寸，它应该调整大小并以16：9的比例裁剪。

刚刚裁剪不是很好。我想要更多地调整图像大小，如果需要可能会裁剪。或者更好：我想尽可能多地从原始图像重用，但调整大小并将其裁剪为中心，这样我就可以在一个固定的html div中使用它，比例为16：9。

谢谢！

Answer 1

这是我多次使用的解决方案。这应首先调整大小，然后在任何超出的维度上裁剪。图像不会被拉伸。

using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;

protected Image imageCrop(Image image, int width, int height, AnchorPosition anchor)
{
    int sourceWidth = image.Width;
    int sourceHeight = image.Height;
    int sourceX = 0;
    int sourceY = 0;
    int destX = 0;
    int destY = 0;

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

    nPercentW = (Convert.ToSingle(width) / Convert.ToSingle(sourceWidth));
    nPercentH = (Convert.ToSingle(height) / Convert.ToSingle(sourceHeight));

    if (nPercentH < nPercentW)
    {
        nPercent = nPercentW;
        switch (anchor) {
            case AnchorPosition.Top:
                destY = 0;
                break;
            case AnchorPosition.Bottom:
                destY = Convert.ToInt32(height - (sourceHeight * nPercent));
                break;
            default:
                destY = Convert.ToInt32((height - (sourceHeight * nPercent)) / 2);
                break;
        }
    }
    else
    {
        nPercent = nPercentH;
        switch (anchor) {
            case AnchorPosition.Left:
                destX = 0;
                break;
            case AnchorPosition.Right:
                destX = Convert.ToInt32((width - (sourceWidth * nPercent)));
                break;
            default:
                destX = Convert.ToInt32(((width - (sourceWidth * nPercent)) / 2));
                break;
        }
    }

    int destWidth = Convert.ToInt32((sourceWidth * nPercent));
    int destHeight = Convert.ToInt32((sourceHeight * nPercent));

    Bitmap bmPhoto = new Bitmap(width, height, PixelFormat.Format24bppRgb);
    bmPhoto.SetResolution(image.HorizontalResolution, image.VerticalResolution);

    Graphics grPhoto = Graphics.FromImage(bmPhoto);
    grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
    grPhoto.DrawImage(image, new Rectangle(destX, destY, destWidth, destHeight), new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight), GraphicsUnit.Pixel);
    grPhoto.Dispose();

    return bmPhoto;
}

public enum Dimensions
{
    Width,
    Height
}

public enum AnchorPosition
{
    Top,
    Center,
    Bottom,
    Left,
    Right
}

以下是对函数调用的示例：

Image image = image.FromFile(imagePath);
Image thumb = imageCrop(image, 100, 100, AnchorPosition.Top);

Answer 2

我做了类似的事情来创建标准尺寸的缩略图。这是代码的链接（在博客文章中）。

http://blog.bobcravens.com/2009/07/mobileme-scrolling-image-viewer/

概念是一样的。我使用了一些逻辑来根据尺寸自动选择要裁剪的位图区域。

希望这有帮助。

鲍勃

Answer 3

您可以使用此代码：

 Size NewSize = new Size();
                NewSize.Width = 70;
                NewSize.Height = 60;
                System.Drawing.Image small = resizeImage(Image.FromFile(source), NewSize);
                small.Save(your path);

//这是调整大小的功能

    public System.Drawing.Image resizeImage(Image imgToResize, Size size)
        {
            int sourceWidth = imgToResize.Width;
            int sourceHeight = imgToResize.Height;
            float nPercent = 0;
            float nPercentW = 0;
            float nPercentH = 0;
            nPercentW = ((float)size.Width / (float)sourceWidth);
            nPercentH = ((float)size.Height / (float)sourceHeight);
            if (nPercentH < nPercentW) nPercent = nPercentH;
            else
                nPercent = nPercentW;
            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);
            Bitmap b = new Bitmap(destWidth, destHeight);
            Graphics g = Graphics.FromImage((Image)b);
            g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
            g.Dispose();
            return (System.Drawing.Image)b;
        }

将图像c＃/ asp.net调整为特定格式（宽屏16：9）

3 个答案: