[WPF] 이미지 자르기

사각형, 타원, 삼각형으로 이미지를 자르기 위해 아래처럼 정의합니다.

public enum ShapeType
{
    Rectangle,
    Ellipse,
    Triangle,
}

이미지 자르기

기존 비트맵 이미지에서 주어진 위치과 크기, 도형을 통해 이미지를 자릅니다.

public Bitmap CreateCroppedImage(Bitmap image, double left, double top, double width, double height, ShapeType shapeType)
{
    Bitmap result = new Bitmap(image.Width, image.Height);
    using (Graphics g = Graphics.FromImage(result))
    {
        RectangleF srcRect = new Rectangle((int)left, (int)top, (int)width, (int)height);

        switch (shapeType)
        {
            case ShapeType.Rectangle:
                g.DrawImage(image, new Rectangle(0, 0, result.Width, result.Height), srcRect, GraphicsUnit.Pixel);
                break;
            case ShapeType.Ellipse:
                {
                    int x = (int)width / 2;
                    int y = (int)height / 2;

                    g.SmoothingMode = SmoothingMode.AntiAlias;
                    g.TranslateTransform(result.Width / 2, result.Height / 2);
                    GraphicsPath gp = new GraphicsPath();
                    gp.AddEllipse(0 - x, 0 - y, result.Width, result.Height);
                    Region rg = new Region(gp);
                    g.SetClip(rg, CombineMode.Replace);

                    g.DrawImage(image, new Rectangle(-x, -y, result.Width, result.Height), srcRect, GraphicsUnit.Pixel);
                }
                break;
            case ShapeType.Triangle:
                {
                    float x1 = 0;
                    float y1 = 0;
                    float x2 = (float)(x1 + width);
                    float y2 = (float)(y1 + height);

                    PointF[] destPoints =
                        {
                        new PointF(x1 + (x2 - x1) / 2,  y1),
                        new PointF(x2,  y2),
                        new PointF(x1,  y2),
                    };

                    GraphicsPath gp = new GraphicsPath();
                    gp.AddPolygon(destPoints);
                    Region region = new Region(gp);
                    g.SetClip(region, CombineMode.Replace);

                    g.DrawImage(image, new Rectangle(0, 0, result.Width, result.Height), srcRect, GraphicsUnit.Pixel);
                }
                break;
        }
    }

    return result;
}

이미지 제외 나머지 부분 제거

기존 비트맵 이미지에서 주어진 위치과 크기, 도형을 통해 이미지를 제외한 나머지 부분을 제거합니다.

public Bitmap CreateInvertCroppedImage(Bitmap image, double left, double top, double width, double height, ShapeType shapeType)
{
    Bitmap result = new Bitmap(image.Width, image.Height);
    using (Graphics g = Graphics.FromImage(result))
    {
        switch (shapeType)
        {
            case ShapeType.Rectangle:
                Rectangle rect = new Rectangle((int)left, (int)top, (int)width, (int)height);
                g.SetClip(rect, CombineMode.Exclude);
                break;
            case ShapeType.Ellipse:
                {
                    GraphicsPath gp = new GraphicsPath();
                    gp.AddEllipse((int)left, (int)top, (float)width, (float)height);
                    Region region = new Region(gp);
                    g.SetClip(region, CombineMode.Exclude);
                }
                break;
            case ShapeType.Triangle:
                {
                    float x1 = 0;
                    float y1 = 0;
                    float x2 = (float)(x1 + width);
                    float y2 = (float)(y1 + height);

                    PointF[] destPoints =
                        {
                        new PointF(x1 + (x2 - x1) / 2,  y1),
                        new PointF(x2,  y2),
                        new PointF(x1,  y2),
                    };

                    GraphicsPath gp = new GraphicsPath();
                    gp.AddPolygon(destPoints);
                    Region region = new Region(gp);
                    g.SetClip(region, CombineMode.Exclude);
                }
                break;
        }

        Rectangle destRect = new Rectangle(0, 0, result.Width, result.Height);
        Rectangle srcRect = new Rectangle(0, 0, result.Width, result.Height);

        g.DrawImage(image, destRect, srcRect, GraphicsUnit.Pixel);
    }

    return result;
}